Lotus Europa Community
Lotus Europa Forums => Technical Articles and DIY tools and tips => Topic started by: Lotus 47 on Monday,October 03, 2016, 10:00:01 PM
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I've started this topic to record lots of details on my upper link rear suspension fitted to my 1970 Type 54 S2 - 7004100119Q
There is some existing information at
http://lotus-europa.com/0119q/index.html
A number of modifications accompany this upper link, so there is a lot to absorb.
Why did I do this? I was sick and tired of changing universal joints, and frustrated by the LH drive flange constantly coming loose. A fellow Europa owner lost his LH rear wheel on the track, probably as a result of constantly applying high torques to his LH stub axle nut, to the point where the end of the stub axle and nut disappeared into the weeds, while his whee,l brake drum and drive flange shot off and hopefully didn't hit anything.
My initial aims
- replace the U/J's with CV joints
- add an upper link because the CV joint is designed to change length, and cannot replace the fixed length drive shaft
- find an alternative to the Hillman Imp stub axle
My assumption for the upper link was that it should have a length that is a close as possible to the fixed length drive shaft it was replacing, and that the installed angle of the link should match the installed angle of the fixed length drive shaft.
As a starting point, let's look at the inner upper link mount. The casing of the Renault box is massively strong where it mates to the bell housing, so I built some brackets to pick up existing bolt holes.
I used a piece of 3mm mild steel for the rear flat bracket, and a piece of 3mm thick steel angle for the front bracket. The front bracket dictated where I could mount easily onto the bell housing.
Look at the photos and it is all pretty much self explanatory.
Please note the photos show a Type 395 box which is a 5 speed. The Type 336 4 speed will be very similar.
This design assumed CV joints, and used a complete CV drive shaft from circa 1980 Alfa Romeo Alfetta. These cars used a rear mounted transaxle and de Dion. I happen to own an Alfetta when I did this modification.
The drive shafts are unmodified . I did not want cut/shut shafts in this design, or get new shafts made. I am always very cost conscious when I make a modification.
The drive shafts and links have now been installed for about 200,000km with engines varying from 120-160hp.
In this first batch of photos you will see my links. These are simple ERW tube 1" diameter, with mild steel bosses. The bosses are brazed using what Aussies call "silver solder" or COMCOAT silver 45. I used 1/2 ball joints so they would mount to the existing fasteners for the lower links. All ball joints are RH thread. Half a turn provides accurate setting of the suspension.
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Excellent, I'm looking forward to the next installment. Your take on mounting the top link is an interesting one, I don't think I've seen anyone do that before.
Brian
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I'm interested in the next installment, too. A friend who is building an S2 with a Ztech is implementing your design and I've been following his progress.
My understanding is that you are preserving the original geometry and taking loads off the drive shafts. I understand that the rear wheel bearings were a weak point in the S2s. Does your mod help that situation?
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Yes, I'm very interested as well. I'm interested in the modifications and the reasons for them. Cheers :beerchug:
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I have found the rear wheel bearings to be Ok. My BMW stub axle conversion has a 30mm shaft, so the inner bearing is now a standard 6006-2RS. The 2RS means the bearing is fitted with 2 Rubber Seals. I might be onto my 3rd set of of rear wheel bearings after 29 years and 250,000km.
Here are a few photos of the CV, the mounting flange and its proximity to the inner upper link mounting brackets.
I've also added some photos from inside the bellhousing to show the tightly bunched bolts
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I'll get some more photos of the drive flange, and show how it replaces the existing Europa bits. There are a few things to observe for the uninitiated!
This next photo shows the forward mounting for the trailing arms. I pulled the engine out last weekend and thought I should take a picture of the mount in situ. I have more photos buried on a hard drive somewhere. I'll dig them out.
I never liked the rubber bushes at the front of the trailing arms. They were designed for axial load in the rear suspension of a Rover P6. My original ones were stuffed, and I bought new replacements, but they looked dodgy to me. So after fitting ball joints and upper links at the rear of the trailing arms it made sense to locate the front of the trailing arms precisely with ball joints.
The bolt is 7/16", so I bought 2 generic 7/16" ball joints. I machined a tube about 25mm long, which would accept the ball joint inside with a light push fit. The wall thickness of the tube is about 2-3mm to fit. The rest is 3mm flat plate and some simple stiffeners. I used a stick (arc) welder to make these 20+ years ago and they are still working perfectly with no signs of wear to the bush, or cracking of the fabrication. I also made a steel spacer so I could re-use the existing 7/16" bolt.
Note that the ball joint is held in by simply crimping or distorting the tube. Crude but effective! No point in over engineering.
Cheap & cheerful, and very effective. I did experiment with different rubber bushes, and it was a complete waste of time. I found under hard acceleration the car squirmed. You could feel the rubber bushes deflecting each side which cause a touch of rear wheel steer.
Now you can hit the accelerator, drop the clutch, light up the rear wheels and it will launch straight.
This is one of my favourite mods because it is so simple, and one that is rarely mentioned.
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Nice mod, Richard! It looks very efficiently done (on many levels)!
What am I missing? That picture is taken from the inside of the backbone, right? (it seems like it would be easier to adjust the rear toe if the bolt were turned around - i.e. we would see the bold head in this pictures - another reason why I think I'm missing something) The crimps in the tube keep the ball joint from going into the backbone. What keeps it from falling out?
I have found with the rod ends on my rear suspension that they wear pretty rapidly. After a few thousand miles (don't know how many because my speedo didn't work then) the rod ends lost all their preload and they could easily be moved in the race. Obviously, they aren't worn out but I was concerned enough to get rubber boots for them. It sounds like you don't have any issues with the ball joint wearing out? Do you think that's because it is shrouded in the tube or do you have some sort of seal to protect it (given how simple you made it, I thinking not).
I remember the bolt fits either the trailing arm or the original rubber bush but I don't remember which. Is it the trailing arm?
Has your toe setting been very stable? Have you had to adjust it over time?
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I have always thought that the rubber in the trailing arm mounts and in the gearbox mounts at the rear of the frame deflect enough to change the rear toe-in when you back off the throttle or brake hard. My thought is this rubber deflection is what can make the car 'tail happy'. Anyone have any thoughts on this?
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Nice mod, Richard! It looks very efficiently done (on many levels)!
What am I missing? That picture is taken from the inside of the backbone, right? (it seems like it would be easier to adjust the rear toe if the bolt were turned around - i.e. we would see the bold head in this pictures - another reason why I think I'm missing something) The crimps in the tube keep the ball joint from going into the backbone. What keeps it from falling out?
I have found with the rod ends on my rear suspension that they wear pretty rapidly. After a few thousand miles (don't know how many because my speedo didn't work then) the rod ends lost all their preload and they could easily be moved in the race. Obviously, they aren't worn out but I was concerned enough to get rubber boots for them. It sounds like you don't have any issues with the ball joint wearing out? Do you think that's because it is shrouded in the tube or do you have some sort of seal to protect it (given how simple you made it, I thinking not).
I remember the bolt fits either the trailing arm or the original rubber bush but I don't remember which. Is it the trailing arm?
Has your toe setting been very stable? Have you had to adjust it over time?
1 - the photo of the trailing arm bush is taken from inside the chassis
2 - the bolt heads are on the outside, because the trailing arm is VERY close to the chassis, and there is not enough room for a nut and washer
3 - the steel bracket I fabricated has a clearance hole for the 7/16" bolt. Lets say the hole is 1/2". That stops the ball joint from falling outboard. A picture tells a thousand words and I don't have a picture on hand.
4 - My first upper link design was fitted to my 4 speed, and I used ball joints with nylon races. They pounded out in no time. So spend the money here and buy ball joints with stainless steel balls and stainless races, with a Teflon insert.
5 - the bolt in the front of the trailing arm is 7/16". There is a steel bush welded in to the trailing arm, with a 7/16" holes through it. I didn't want to unnecessarily modify the trailing arm, so I kept it standard and re-used the original bolt.
6 - I particularly dislike the 105E Ford engine mounts and rear gearbox mount (R16 part) They provide heaps of compliance, which means the engine can roll around like one of these silly emojis :FUNNY:
As soon as you drive the car hard, the engine and gearbox are jerking around all over the place. You go from 2nd gear and can't find 3rd cos it ain't where it used to be. The twin cam went some way to solving this by adding a decent mount to the rear of the box. You can clearly see my solution in the "bare chassis " photo
7 - my rear suspension settings are stable. I run 5.5" Cosmic mags and 205 rear tyres. I trimmed the rear guards to make this fit with the original suspension, and my twin link runs identical track as far as I can tell. The camber is no more than 0.5 degrees negative. I like to run the tyres fairly square to the road to maintain a big tyre contact patch. I run about 4mm toe-in. That is a difference of 2mm per side between the rear of the tyre and the front of tyre.
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I have always thought that the rubber in the trailing arm mounts and in the gearbox mounts at the rear of the frame deflect enough to change the rear toe-in when you back off the throttle or brake hard. My thought is this rubber deflection is what can make the car 'tail happy'. Anyone have any thoughts on this?
Hi Tom,
I see you have found my thread!
In the previous post you'll see my thoughts on the rubber in the standard set-up. I am not a fan!
On a road where you have 2 lanes , often I would find the car darting all over the place as I changed lanes.
Fitting ball joints helped.
Fitting the twin cam style rear gearbox mount helped.
Fitting different engine mounts helped. MORE ON THIS LATER
Understanding what the front suspension was doing helped. THAT'S A WHOLE NEW TOPIC CALLED BUMP STEER!
There are many many interlinked issues going on in the rear, and I will try and address all of them.
A standard 80hp S1 is a delightful and nimble car to drive. Put 100hp or 120 hp into and S1 or S2 with fat sticky tyres, and things start to move, loosen, break, etc.
Hopefully I can answer all your questions on line here, so they can be shared with everyone, but feel free to contact me on email richard.mann047(at)gmail.com
Cheers!
Richard
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Richard,
I'm very interested in seeing the CV drive flange. I'm going to running VW Golf shafts on my car and I've picked up a set of 100mm inner flanges from a VW gearbox, but I'm undecided on the way to adapt them. Did you machine up a complete output shaft, or did you cut and weld the Lotus (or Renault) output shaft to the Alfa output shaft/flange?
Rod
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Thanks for the answers to my questions. But...
3 - the steel bracket I fabricated has a clearance hole for the 7/16" bolt. Lets say the hole is 1/2". That stops the ball joint from falling outboard. A picture tells a thousand words and I don't have a picture on hand.
So what you're saying is the plate has a bigger hole than the bolt (1/2") and you crimped the tube after you put the ball joint in?
Theoretically, your alignment shouldn't change. It's nice to know the theory holds sometimes!
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Yes - I installed the ball joint then crimped the tube on my fabricated bracket.
More photos below.
The outer bracket is attached using the 4 x 5/16" UNC bolts in the aluminium upright. So no load goes thru the steel trailing arm. I did try bolting to the trailing arm but it started to distort.
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and another
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BMW stub axles - all of this stuff has been posted for some time now, but I'll repost it here so every thing is together in one spot.
The Microsoft Word document (if it loads) details the stub axle change using a fixed length drive shaft, but the installation is not any different to the CV drive shaft conversion on my car.
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Still have drum brakes!?
Which BMW stub axle dd you use?
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I really like the solution you've arrived at to mount the upper link on the hub carrier, again that's not something I've seen before, every solution I've seen so far has been for the S2 and using a bottom mounted construction which then travels upwards to locate the upper link.
I'm not about to do a conversion on mine but I keep looking about for a 5 speed box and should one come up, I'll probably go that way. I can't see how the S2 solution would work on mine without drilling the carrier and moving the damper mount, which I'm loathe to do. I had thought of welding a bracket on the trailing arm about where the handbrake stop is now, which is almost the same geometry as you've done. So it's encouraging to see someone with experience of that arrangement.
As you've experience of this arrangement, do you think there's any reason why a welded bracket on the arm wouldn't work as well as your bolted set-up ? I'd be interested in your comments because I think you've solved the inboard mount position in a very neat way. (Yes, I'm going to pinch that idea :) )
Brian
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Still have drum brakes!?
Which BMW stub axle dd you use?
Yes I still have drum brakes on the rear.
The definitive answer for the question "Which BMW stub axle did you use?"
is answered with "I don't know."
About 20 years ago I went to BM Spares in Melbourne with a Hillman Imp stub axle in one hand, and a vernier caliper in the other.
Back then they stripped everything down and put them in big plastic tubs. it was like going to the supermarket.
I picked out a pair of shafts with 30mm bearing surfaces with roughly the same bearing spacings, a flat drive flange, and a drive hub with 4 studs. I think they had 2000 written on them. Maybe a 2000 sedan circa 1970 which pre dated the 1602/2002.
I converted another car a few years later, and I know of 4 other owners that copied my design.
A few years later I bought a pair of 320 shafts for future use, only to find they had 28mm bearing surfaces. Ooops!
A search on the net identified that the 323i used 30mm bearings.
My sketch gives the dimensions of the shafts I used.
Unfortunately these days people don't rebuild BMW's. They drive them til they die, then sell them for scrap.
I am always on the look out for the next stub axle to suit my conversion.
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Hmm... That.will make it harder. I think (hope) that the weaknesses of the rear corners of the S2 were solved on the TC but I know that stub axles are not hardened and that concerns me. Maybe it would be a good idea to join some BMW forums and ask around.
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Richard -
Thanks for writing your conversion up! I have printed all I could find on the yahoo group. I'm going to be using your idea in the near future.
"I am always on the look out for the next stub axle to suit my conversion"
One conversion on the Yahoo group used VW beetle stub axles, and axles. Did you read of this conversion? If so, what did you think of it?
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Richard -
Thanks for writing your conversion up! I have printed all I could find on the yahoo group. I'm going to be using your idea in the near future.
"I am always on the look out for the next stub axle to suit my conversion"
One conversion on the Yahoo group used VW beetle stub axles, and axles. Did you read of this conversion? If so, what did you think of it?
I haven't read the VW conversion, but I am already onto it!! It is the next idea I will explore. See attached exploded view. The stub axles and drive flange are perfect donors, as long as they measure up!
I've also attached a screen dump of a 2002 Turbo exploded parts view. 2002 Turbos don't exist in Australia, so the stub axle must have come from a high volume donor vehicle. The Turbo parts looks very familiar because it has 12 holes in the drive flange.
More BMW pictures attached. The stub axle has a 24mm thread on the end - the Hillman Imp has 3/4" UNF which is 19mm, so the BMW one grabbed my attention because I knew it could withstand a much higher torque and apply a bigger clamping load to the bearings, hub and spacers.
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Missed the Turbo picture. here it is
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And some more to keep you distracted from work, household chores etc.
I made these engine mounts in 2005 with only one aim in mind - TO STOP THE ENGINE ROLLING AROUND A LETTING THE REAR SUSPENSION MOVE.
I had many failures with the old shear mounts due to poor quality manufacture. These mounts transmit more vibration, but make a considerable difference to the cars handling.
I'm currently rebuilding an S2 Elan and note the Tony Thompson Racing offer similar mounts.
The last picture was taken by a guy with a Subaru Forester that had been lowered and tweaked. He loved my car so much he photo-shopped it and sent me this picture. :coolpic:
The Europa attracts more attention than any other car I've ever driven.
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As you've experience of this arrangement, do you think there's any reason why a welded bracket on the arm wouldn't work as well as your bolted set-up ? I'd be interested in your comments because I think you've solved the inboard mount position in a very neat way. (Yes, I'm going to pinch that idea :) )
Brian
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I like to do modifications that are easily reversible.
Sometimes they don't work.
Sometime in the future someone may want to convert the car back to original.
You may have noted that I removed the rear hoop from the chassis to incorporate my 5 speed conversion. I carefully cut the original cross member off in such a way that it could be welded back in.
So I am always mindful of how I modify something. I try and make it reversible and I try and make it simple/cheap.
The outer bracket is bolted because I didn't know if it would work. The bracket started life as a bit of 4"x4"x1/8" square tube. It looks ugly to me, but it is effective!
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Richard,
I'm very interested in seeing the CV drive flange. I'm going to running VW Golf shafts on my car and I've picked up a set of 100mm inner flanges from a VW gearbox, but I'm undecided on the way to adapt them. Did you machine up a complete output shaft, or did you cut and weld the Lotus (or Renault) output shaft to the Alfa output shaft/flange?
Rod
The flange is a piece of 1/4" steel plate - nothing fancy. It is welded to a female spline that came from a donor Renault drive shaft, so if you find some old dead Renaults take the drive shafts so you can use the end spline.
The following cars use the same spline - R12, R15, R16, R17, R18, Fuego. Maybe the R20 with the 1647 engine.
I'll find photos, or take photos .
Lastly these cars all use 6mm roll pins, and the Europa uses 7mm roll pins with another smaller one inside.
I haven't use roll pins for about 20 years. I use a 7mm bolt.
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2 - the bolt heads are on the outside, because the trailing arm is VERY close to the chassis, and there is not enough room for a nut and washer
Not particularly clear photos but you can see how close my trailing arm is to the chassis, dictating bolt heads to the outside!
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The flange is a piece of 1/4" steel plate - nothing fancy. It is welded to a female spline that came from a donor Renault drive shaft, so if you find some old dead Renaults take the drive shafts so you can use the end spline.
Thanks for the info, that was going to be my original plan of attack with just machining a plate, but I've changed course slightly by obtaining the VW flanges. I'm planning on turning down the Renault CV and boring the VW flange to have a slight interference fit, then weld them together. Now I just need to find another dead Renault CV axle, the gearbox i picked up had the remains of one. I wish it had two.
Rod
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Thanks for the extra photos, Richard! Your trailing arm is much closer to the frame than on my TCS!
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A fellow Europa owner lost his LH rear wheel on the track, probably as a result of constantly applying high torques to his LH stub axle nut, to the point where the end of the stub axle and nut disappeared into the weeds, while his whee,l brake drum and drive flange shot off and hopefully didn't hit anything.
Oooops . . that was probably me.
Hi Richard. :)
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I like to do modifications that are easily reversible.
Sometimes they don't work.
Sometime in the future someone may want to convert the car back to original.
You may have noted that I removed the rear hoop from the chassis to incorporate my 5 speed conversion. I carefully cut the original cross member off in such a way that it could be welded back in.
So I am always mindful of how I modify something. I try and make it reversible and I try and make it simple/cheap.
The outer bracket is bolted because I didn't know if it would work. The bracket started life as a bit of 4"x4"x1/8" square tube. It looks ugly to me, but it is effective!
Thanks for coming back, I understand your reasoning, it's always good not to burn too many bridges.
"simple/cheap" works for me as well ! :)
Brian
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"I haven't read the VW conversion, but I am already onto it!! It is the next idea I will explore. See attached exploded view. The stub axles and drive flange are perfect donors, as long as they measure up!"
They measure up closely. Following is part of trimarandan's write up from the knowledgebase;
VW axles are a great alternative. I just uploaded 2 pics of my new VW axles
into the 2474R album. The axles to use come from 68-79 VW IRS Bugs. I bought
mine from a local pull it yourself JY for $11 each. If anybody else pulls a
set, make sure to get all the VW spacers as well, they are far superior to the
Lotus spacers. Many of the sand rail shops sell chromoly bullet proof new axles
on line. However, these chromoly axles will have flanges to use VW bus or
Porsche 930 CV joints which are stronger than bug CVs and able to operate a
greater angles. Our cars are not dune buggys with huge suspension travel, so I
will be installing stock VW CV axles shortly. The VW Bug axles are 30mm so they
go right into stock lotus bearings. The VW axles are dimensionally very similar
to Lotus so there is very little hassle with installation. Leave the first VW
spacer on the axle. This will be the spacer next to the CV flange, the one that
the VW seal rode on. Next, use the small Lotus spacer, the one about .382"
thick. The new axle then goes into the inner wheel bearing, through long
spacer, and emerges through the outer wheel bearing. Next, use the medium sized
VW spacer, it measures about .632" thick. This system will put the CV flange in
about the right spot, and more importantly, it will put the inside of the wheel
flange just where it needs to be (.009" more outboard than where the Lotus wheel
hub set). The wheel hub now goes on followed by the VW axle nut which is
torqued to 230-250 ft pounds. Between the wheel bearings, I used the VW spacer
which is German quality and VERY hard. My upright bearing carriers showed some
wear as I expect they all do. To adjust for this wear, do the following:
install the inner wheel bearing in the carrier and make sure it is all the way
home. Then use the depth measurement rod of a digital caliper to measure inside
the carrier from the inner bearing inner race to the ridge where the outer
bearing seats. Take 4 measurements at 90 degrees. The longest of these 4
measurements is the length that you want the spacer between the bearings to be.
I have TC/TCS carriers, so the stock Lotus spacer was 2.125" long. My adjusted
spacer needed to be shorter, but I don't remember the length (maybe .020-.050"
shorter). The VW spacer is about .100" longer than Lotus. Wearing mechanics
gloves, I held the spacer up against the face of a new grinding wheel in a 4
1/2" angle grinder. The spacer was constantly spun in an attempt to keep the
face square. Grind only one end and measure with calipers each time you need to
cool the spacer with water. With care, I was able to keep the run out in the
ground edge to about .005". When I got close to size, I chucked it up in my
lathe and finished to size. Even without the lathe, I think I could have
finished it square with selective grinding and using an oil stone. Anyway, the
results are spectacular, zero play in the new axles/bearings and resistance free
as the axles are spun by hand. If there is a fly in the ointment with this VW
axle conversion, it is with the wheel hubs. In the bug, the brake drum and hub
are one unit. In my donor car, a PO had bought undrilled drums and had a 4 x
100 bolt pattern drilled using 7/16" 20 threads. This is just the pattern I
want to end up with, so I bought the drums/hubs and cut the drum off. The OUTER
face of the new wheel hub was then machined to Lotus thickness, leaving a step
for the Lotus brake drum to center on. All other steps on the new hub were
cleaned up to use for centering wheels. About 1/4" needs to be removed from the
outermost face of the VW wheel hub where the axle nut rides so that the cotter
pin hole will be exposed. An alternative Wheel hub is the VW type 3 which had
rear disc brakes and a separate hub. These hubs can be bought on line from
MOFOCO for $48 each. They will need similar machining to use in a Europa.
*In re-reading trimarandan's write up, he gives you credit as he copied your twin link design!*
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The relevant photo album:
https://groups.yahoo.com/neo/groups/LOTUSEUROPA/photos/albums/2080258933
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A fellow Europa owner lost his LH rear wheel on the track, probably as a result of constantly applying high torques to his LH stub axle nut, to the point where the end of the stub axle and nut disappeared into the weeds, while his whee,l brake drum and drive flange shot off and hopefully didn't hit anything.
Oooops . . that was probably me.
Hi Richard. :)
Hi Gavin!
Why not post some info on your dato conversion?
I found another sketch of the my front trailing arm replacement bush. See below.
Thanks also to Andy for posting the VW info. I need to find a Melbourne wrecker that does Bugs.
Cheers!
Richard
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Richard,
The inside attachment point of your new link has the forward side bolted to the aluminum bell housing with two cap allen screws. Question - did you drill and tap for these two cap allen screws or did you just drill holes and provide a washer and nut inside the bell housing? Is there enough room inside the bell housing for the washers and nuts without coming afoul with the clutch cover?
Tom
74 TCS - 4605R
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Richard,
The inside attachment point of your new link has the forward side bolted to the aluminum bell housing with two cap allen screws. Question - did you drill and tap for these two cap allen screws or did you just drill holes and provide a washer and nut inside the bell housing? Is there enough room inside the bell housing for the washers and nuts without coming afoul with the clutch cover?
Tom
74 TCS - 4605R
They are bolts, he posted a pic in reply#4.
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This photo shows the two cap allen screws into the aluminum bell housing - are there nuts inside the bell housing or has Richard tapped and threaded the aluminum bell housing? Is there actually enough room inside the bell housing for washers and nuts?
Tom
74 TCS - 4605R
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I think this is the picture Blaster was referring to:
(http://www.lotuseuropa.org/LotusForum/index.php?action=dlattach;topic=1724.0;attach=9613;image)
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Richard - can you comment on my last post?
Tom
74TCS - 4605R
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Photo showing nuts inside the bell housing:
http://www.lotuseuropa.org/LotusForum/index.php?action=dlattach;topic=1724.0;attach=9612;image
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Richard - can you comment on my last post?
Tom
74TCS - 4605R
Hi Tom,
I drilled through the bell housing and fitted nuts on the inside. There is very little room. I even deleted the washers due to the tight cluster of bolts/nuts. I do not trust threading into the bell housing. I fitted a larger 215mm clutch. There is heaps of clearance to these bolts/nuts, because they are so far rearwards - much further rearwards than the face of the throw-out bearing.
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Thanks Richard - could you use a self-locking nut plate inside the bell housing? I have used them elsewhere on the frame - they get pop riveted in place, then you can remove the bolt while the nut plate stays in place. The nut on the nut plate is also self-locking.
Tom
74 TCS - 4605R
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I was going to say that I don't think you'd get the clamping support with a nut plate that you'd get with a nut and washer especially in a situation where you're not clamping against a flat surface (and if you happened to have seen this post before I edited it, that's what you'd see. After looking at the pictures again, I still think that's true but I don't think it's as serious an issue as I imagined.
I wouldn't think it's a joint that you're likely to have to take apart after it's been correctly put in place so you'd be going to more trouble to make it something you can take apart and put back together with minimal fuss. In fact, I think it wouldn't be a bad idea to use red loc-tite - just a belt and suspenders way of thinking about it. After all, if the mount for the upper link were cast into the bell housing, you'd probably like that even better!
Just my $0.02.
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Why not post some info on your dato conversion?
Well, it’s not much more than an idea but I’ve done some rough measuring.
Losing a rear wheel at a fair clip does tend to focus the mind.
Probably the main cause of that incident was the compression of the outer 3/8” spacer. It was somewhat mushroomed - obviously too soft.
Having obtained a couple of Hillman Imp axles I had some alloy spacers machined up which were installed on the wheel mounting face. This allowed the elimination of the outer axle spacer and gained 3/8” more spline engagement as well. This worked fine but I reckon the axles are marginal in any case particularly if one ventures onto the track. Two pics attached.
(https://s22.postimg.org/xcivshu6p/Spacer.jpg)
(https://s22.postimg.org/i52w852c1/Spacer_Hub.jpg)
The next pic shows a Datsun 240Z axle which is pretty much the same as a Datsun 1600/510.
(https://s22.postimg.org/q7wh5pxjl/S30_Stub_Axle.jpg)
This axle uses 2 x 6206 bearings on a 30mm shaft . . . similar to the Europa TCS but could also accept a 6206 and 6006 bearing of the S2 and the Europa spacer. The Datsun spacer is only a little longer.
The features I liked were the one piece axle & outer flange with no external threaded portion to break off. The outer bearing is also hard up against the wheel mounting flange without the cantilever feature of the Europa axle.
That’s all fine but it does mean that the wheel mounting face is ~ 25 mm further inward. A 25 mm spacer outboard of the outer bearing would bring this into line I reckon. I’ve yet to fit the arrangement into a Lotus upright but it should work.
The Datsun inner end uses a four bolt flange with a factory torque spec. of 181-239 ft-lb.
Obviously this would require new half shafts. A good opportunity to upgrade to bigger UJ’s or go the whole hog with CV’s . . perhaps VW Type II or Porsche 930 half-shafts.
CV adaptors for the four bolt flange are already available and used by the Datsun 510 crowd.
Still interested to see the VW stuff too.
Cheers,
Gavin
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Here is a quick snap of the Lotus stub axle beside a VW stub axle, including spacers and nuts. The VW axle nut torque spec is 350 ft. lbs., VW axle uses stock Lotus bearings. Seems the VW axles/drive shafts are used in fairly high horse power drag cars, so should be up to a Europa load. I'll get some bearings, mount everything up in a carrier, get some measurements soon, and post. Finally getting where I can spend some time on the Lotus...
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That's pretty interesting, Andy! When you get everything together, maybe you can provide a parts list and any instructions or required mods.
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I really like the Dato set-up where the spline is well away from the flange that mounts the wheel.
I did get a bit carried away last week and bought a couple of VW bits so I can investigate further. These ones have drum brakes, so I will machine the drum away and be left with a drive flange.
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Richard & Andy,
What is the donor car for those VW bits?
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Gavin,
According to trimarandan's yahoo group write up of his conversion, he used 68-79 VW beetle stub axles, spacers and drive axles.
Following link about CV joints and axles I found interesting, but then, it's the first time I've ever read anything about CV joints. YMMV
http://blindchickenracing.com/How_to/CVJoints_Axles/cv_joints_101.htm
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Thanks Andy,
I’m not full bottle on CV’s either but the various VW varieties seem to be widely used and that bodes well for finding correct shaft lengths, I’d presume.
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yes, various shaft lengths available. And to some degree, the various CV's are mixable - which may help to mate a stock length drive shaft to the Europa. Plus the fact the original German parts are of very good quality steel.
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The Lotus (Hillman Imp) pieces are crap - they are not hardened. They work (most of the time), but I can't imagine that the German pieces would not be hardened.
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Hey guys, not sure how crazy you want to get with the VW set ups but because of the sandrail industry there are a lot of good upgrade parts at a reasonable price. I did a search and for example you can get a chromoly version of the Beetle stub axle made to mate up with the stronger VW Bus CV for about $100 canadian plus shipping.
https://www.cip1.ca/ProductDetails.asp?ProductCode=C26-525-101
The CVs are also reasonably priced, German made bus CVs are about $90 a piece (4 required) or good quality full half shafts with a CV at each end are $150-$170, new.
Richard I am really interested to see how the VW stuff works out as I think this is a good quality reasonable priced conversion to make a twin link rear suspension and convert to the more modern CV axle set up. Your set up you have engineered is really amazing and I love how simple it is.
Ross
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Today, got the Europa frame back from being sand blasted. Ordered some VW bug axles, and a couple rotors. So, soon will be able to mock this up to see how it fits.
If anyone needs some type 3 hubs to experiment with, I have some new Brazilian made ones - cheap.
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Please keep us posted on your progress. I like the VW approach, but machining the type 3 hub or hub with integral brake drum leaves me with a lot of questions.
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Richard,
How do you handle the inboard end on the half shaft. How do you add a CV flange to the gearbox output shaft?
Tom
74 TCS - 4605R
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I'll hazard answering - for the VW conversion - yes, a cv flange needed. You'll need some Renault output shaft flanges to mod - unless you use the Lotus yokes, which are pricey.
On the 1st page of this thread is a link to the pics on the YH group of the VW conversion. That is what he did, so I'm assuming they are a different size.
I have no idea what size CV Renault used, if 100 mm. I *think* easy to mate up. I say easy, because it seems a 100 mm CVJ will mate with the stock Bug axle of 33 splines.
I purchased CV flanges from Banks. Pricey, but easy. Then, I find that they are Bank's flanges are 100 mm, and the VW Beetle's are 94 mm, so hoping.
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So, do you replace the stock Lotus output shafts with new shafts that have CV flanges or is there a separate CV flange that splines onto the Lotus output shaft and is secured with the stock Lotus roll pins?
Tom
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Conversion I've seen welded a VW pattern flat plate onto output shafts from a Renault Turbo Fuego. Renault tripod type CV was cut off.
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These ones have drum brakes, so I will machine the drum away and be left with a drive flange.
I presume the drums are cast iron, yes?
Will that be OK for a wheel flange? . . I would have thought it'd be too brittle?
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Conversion I've seen welded a VW pattern flat plate onto output shafts from a Renault Turbo Fuego. Renault tripod type CV was cut off.
Yes, that would appear to be how trimarandan handled it.
Looking at his photo album, the output flange looks to be welded around the small diameter of the item.
I'd be worried about that but maybe it's fine.
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Photo of Banks NG3 CV flange. 100mm, if I measured correctly.
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Photo of Banks NG3 CV flange. 100mm, if I measured correctly.
The Banks flange looks superb, Andy.
I couldn’t find it on Banks site though . . drat. If it's not a rude question, what's the price on these?
I wonder if it also works with 3xxx transaxles? I’m not familiar enough with the NG’s but even the 395 has longer output shafts than the 336/365 for instance.
You mentioned the 94 mm flanges so that presumably means Type 1
Here’s a link to some other VW flange differences too.
http://www.brokevw.com/flanges.html (http://www.brokevw.com/flanges.html)
I’m not sure if we are to assume that the 100 mm CV’s are the best and/or more common variety and therefor having better ongoing support.
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Richard,
How do you handle the inboard end on the half shaft. How do you add a CV flange to the gearbox output shaft?
Tom
74 TCS - 4605R
Here is a bit more info on the inboard end of my conversion.
When you remove the original yoke and half shaft from the gearbox output shaft, there are a couple of shims and a special spacer fitted in there. These are not immediately obvious. Look at the work shop manual and exploded parts view to understand what's in there. The special spacer has a groove on the inboard end to accept an O-ring seal, and the outside surface is smooth to interface with the gearbox lip type oil seal. So this special spacer has two sealing functions.
The special spacer and shims are removed in my conversion.
To replace this special spacer I cut down an old R16 driveshaft. I just cutoff the end bit with the internal spline that goes into the gearbox, and throw the rest away.
The R16 CV is typically French! Absolutely nothing like what everyone else uses in the automotive world. See photo below. It is useless for my conversion.
The other photo shows the end of a R16 drive shaft. I grabbed this photo from ebay. It shows a plastic protective sleeve fitted. This helps to protect the outer surface which is required as a seal surface. The groove in the end of the shaft mates with the O-ring I mentioned earlier. I simply cutoff the splined section, then machine a flat piece of mild steel plate to fit on to the spline. I then machine the whole lot to have ~100mm flange. I recessed the flange by a millimeter or 2 to hold/locate the CV joint, then drill 6 holes in the flange using the CV joint as a template.
The flange is <6mm thick, and I made my first ones about 25 years ago with my dad. We didn't own a MIG or TIG back then, so I preheated the flange/spline with an oxy torch, and dad welded the two with an arc (stick) welder. It worked a treat.
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These ones have drum brakes, so I will machine the drum away and be left with a drive flange.
I presume the drums are cast iron, yes?
Will that be OK for a wheel flange? . . I would have thought it'd be too brittle?
The donor rear suspension arms come from a VW beetle with IRS (independent rear suspension). These started around 1968, and used drums brakes, with those early style VW 5 bolt wheels. The wheels bolted directly into these drum brakes, so I am initially making an assumption they will fine to be turned down into a drive flange with wheel studs inserted.
Later cars used a drive flange, 4 studs and a separate drum. These drive flanges are available new and used out of the US for ~$30ea.
I read somewhere the spline length on the stub axle is shorter for the 4 stud drive flange, but until I get parts in front of my own eyes I'll just work on the parts I have on hand.
I've attached the VW exploded parts view again. Note the different drum/hub arrangements, but it only shows one stub axle. I have seen stub axles advertized in various forms with different overall lengths etc. Buyer beware!
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Tripod CV joints are used in many cars. They are very good on FWDs where short driveshafts change length dramatically as the suspension goes up and down. More than a bit bulky for a Europa, and their ability to change length significantly is not needed but they are plenty strong enough. Virtually no stiction as the length changes unlike the driveshafts with sliding splines that would stick so much under power they would lock the suspension!
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Hey guys, not sure how crazy you want to get with the VW set ups but because of the sandrail industry there are a lot of good upgrade parts at a reasonable price. I did a search and for example you can get a chromoly version of the Beetle stub axle made to mate up with the stronger VW Bus CV for about $100 canadian plus shipping.
https://www.cip1.ca/ProductDetails.asp?ProductCode=C26-525-101
The CVs are also reasonably priced, German made bus CVs are about $90 a piece (4 required) or good quality full half shafts with a CV at each end are $150-$170, new.
Richard I am really interested to see how the VW stuff works out as I think this is a good quality reasonable priced conversion to make a twin link rear suspension and convert to the more modern CV axle set up. Your set up you have engineered is really amazing and I love how simple it is.
Ross
I took these screen shots the other day to show there is plenty of stuff out there.
You can rack up some dollars pretty quickly if you buy it all new.
I bought two trailing arms for AUS$250. Not cheap but in theory they have everything I need. Stubaxles, spacers, drive flange and retaining nut.
I would like to develop a drop in replacement for the original Hillman Imp stub axles, so eventually I'll need to buy a couple of bolt on yokes, and machine the CV flange down to accept them. I may need to cut the flange right off and weld on a U/J yoke. I'll have to get out the trusty vernier, ruler and pen/paper and do some basic layouts.
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"The Banks flange looks superb, Andy.
I couldn’t find it on Banks site though . . drat. If it's not a rude question, what's the price on these?"
I guess the CV flanges are not on the web site, as Richard mentioned them to me. The photo is what he sent to me via email.
Banks price at the time, 296 BP. As Richard said - "Oh, but they are nice".
And so they are!
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" Virtually no stiction as the length changes unlike the driveshafts with sliding splines that would stick so much under power they would lock the suspension"
"Lastly these cars all use 6mm roll pins, and the Europa uses 7mm roll pins with another smaller one inside.
I haven't use roll pins for about 20 years. I use a 7mm bolt. "
John & Richard-
In reading about the different conversions to a twin link suspension, one thing common was not using a pin (or bolt - I had wondered about the viability of this) on the transaxle yoke/flange. This allowed the yoke to move a bit on the output shaft as the suspension moved up & down. Now, I'm wondering if I'm wrong on just being able to remove the roll pin from the CV flange and grease the output shaft for movement.
Could y'all chime in with some insight?
Thanking you in advance.
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Doesn't the CV joint provide plunge? Mine does. I pin mine to the output shaft anyway.
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You need to remove the pins if you are using the original, fixed-length half shafts. Rzeppa CV joints (typical VW joint) accommodate some change in length, certainly more than enough for the very long arm Europa rear suspension.
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Thanks for the input.
From looking at exploded views of VW axles, and reading a bit, I thought that was the case. But - don't have any practical experience.
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Links for VW stuff -
EMPI, lists about every thing, with some specs.
http://vwcatalog.empius.com/default.html
The SAMBA VW forum, w/ classifieds
http://www.thesamba.com/vw/
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Richard,
Do you pin the 100 mm inboard splined CV hub to the gearbox output shaft - same way as the stock U-joint inboard shaft pins to the gearbox output shaft?
Tom
74TCS - 4605R
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Yes, you would pin the CV joint flange to the output shafts.
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Yes, you would pin the CV joint flange to the output shafts.
John is correct. the inboard CV flange and spline is pinned to the output shaft of the gearbox.
A decent CV joint will have the ability to extend/compress by 10mm, so shafts with 2 CV joints will be 40mm shorter when fully compressed compared to fully extended. There is a strong likelihood the inner flange could slip out of the gearbox by 10+mm, so oil will piss out (Australian technical term).
My upper link suspension was installed to over come rapid U/J wear and the possibility of the half shaft winding up and breaking. They are thin and small in diameter, so prone to twist failure.
I am biased but if you are going to play around with the rear end, change the stub axles, install CV joints and fit an upper link. Just do it (American marketing term).
I took a few more photos of the typical R16 CV joints I've cut up in the past. Yet another version of a constant velocity joint that I wouldn't bother with.
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How did you do that (especially the first picture)!? You must have floored it when the rear wheel was locked solid! You certainly know more about the wall thickness of the half shaft than I do, but I've never heard of a failure like that (which means very little) but Jensen's competition manual doesn't mention any mods for the half shafts.
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another :huh: on the twisted shaft.
Is that a standard shaft or one that's been made out of thinner wall section ? Looking at the amount of twisting it looks thin wall, but even so you must have some very sticky tyres on that car !
Brian
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It's just a picture I swiped from the internet to illustrate a point, but it has happened to a friend of mine.
There is a great photo of a Lotus 12 or 16 with a twisted shaft . I think it is in the "Theme Lotus " book tracing the history of Lotus Formula 1
The original shafts (tubes) are small in diameter. I had a replacement made more than 25 years and they couldn't source tube that small. The replacement felt twice as heavy, suggesting the wall thickness of the originals was "light". Lotus wouldn't have it any other way!
A small increase in diameter gives a large increase in torsional stiffness. The stiffness increases to the power of 4 v's radius.
I first saw twisted prop shafts like these when I worked at Kenworth trucks. More recently there has been a spate of prop shaft failures on our local rear drive Holdens and Ford Falcons. With 300kw off the show room floor, and heaps of additional power available with a few tweaks, prop shafts have become the weak link. Our drive shafts take a lot of torque (the diff and gearbox is a torque multiplier) so drive shaft failure and U/J will occur with high horse power.
Our historic race cars do standing starts, and there is nothing like a day of 1/4 mile drags to give your rear end a good work out!
A few years ago I went to a country drag meeting. they had two categories. Below 10 seconds and above. I chose the later. :beerchug:
Pretty sure I was slowest time of the day at around 14.5 seconds :trophy:
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14.5 seconds is pretty darn good for a Europa. Was that a 1/4 mile, what sort of HP do you figure you are getting to get that speed? 160?
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Richard,
Is there an inner CV flange from another car that will fit the Lotus output shaft flange spline and roll pin location or do you take the stock Lotus inner U-joint flange, cut off the U-joint portion and weld on a CV flange?
Tom
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Tom,
I dont think there is any "bolt on" (or pin on in this case) adapter other than what Banks sells. I thought about measuring the diff output shafts in terms of spline count and diameter, then going through the books to find a suitable FWD hub, but I'm fairly certain I wont find a match.
The thought was to take an existing FWD hub and re-drill it to suit the Lobro joint. At the moment, I'm on the look out for a dead Renault CV axle to butcher for the inner CV joint splines then machine and weld to a set of VW output flanges.
Rod
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Richard,
Is there an inner CV flange from another car that will fit the Lotus output shaft flange spline and roll pin location or do you take the stock Lotus inner U-joint flange, cut off the U-joint portion and weld on a CV flange?
Tom
My flanges are flat mild steel plate. I cut off the Renault CV bit from the hollow spline, true up the end of the spline on the lathe, then bore a recess into a bit of mild steel plate to accept the spline. Weld the two, then hold the spline in the lathe and machine a nice true flange to suit the CV joint.
I could machine a flange from solid bar like the Banks part, but it would be very time consuming, and then I'd have to send out the flange to have a spline cut. That is a very expensive solution.
I am lucky I suppose because here in Melbourne they assembled Renault 16's back in the day, and there were thousands of Renault 12 around. Heaps of cars to supply donor splines - however that supply is drying up as these cars are now 40-45 years old.
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I have looked on the Banks Engineering website, but do not find the inner CV hub in his parts catalog - has anyone been able to find it?
Tom
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The CV hub/flange is not listed on Banks website. The photo I posted showing 2 flanges is what Richard sent to me. Price (then) was 396GBP/set
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14.5 seconds is pretty darn good for a Europa. Was that a 1/4 mile, what sort of HP do you figure you are getting to get that speed? 160?
My current engine is around 1765cc, achieved using 81.75mm bores. It has the capacity to produce 160hp, but on the day of the drags it was running lean at the top end and not pulling properly. It was stumbling around 6500-7000rpm but previously my engines would all pulled well into the 8000rpm rang. It was a straight 1/4 mile. It was disheartening to launch the wee beast at full song, and then have a monsterous V8 fly past at about the 1/8 mile and blow me into the weeds.
I should start a new thread on a few of the engines and mods I've built.
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I should start a new thread on a few of the engines and mods I've built.
Yes please!
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I have started another technical thread relating to Renault engines.
It will take awhile to record my experiences, and dig out lots of photos