Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: jjbunn on Sunday,March 26, 2017, 03:12:29 PM
-
I've come to re-mounting the rear wheels. I have new brake pistons and pads installed on both. With the drum off, I can rotate the drive shaft easily by hand. When I place the drum in position, I can rotate the dtum, but it's a bit "graunchy", as if it's catching a little around the rim. When I then mount and tighten the wheel to the drum with the nuts, the wheel wont move at all!
Any help diagnosing this problem would be appreciated - probably it's a stupid error on my part!
Julian
PS are the drums "handed" - is it possible I have swapped the drums and they don't interchange well?
-
Drums are not handed.
What model year and type of Europa do you have?
Most models have a brake adjuster which takes a 1/4" AF wrench. If this is what you have, back off the adjuster before fitting the drum and try again.
The some/most/all TCS models have a wickedly stupid set up with self-adjusting brakes. The adjuster is part of the brake cylinder:
http://www.canleyclassics.com/triumph-gt6-mkiii-brakes-disc-front-and-drum-rear-front-fitted-from-commission-no-ke12389kf12390-rear-fitted-from-commission-no-ke/kf20000
Back it right off and try again. If it is fine, adjust so it is not fine again and then back off until it is "just" ok.
If all this doesn't solve your problem, it might be helpful if you told us why you were in there and what repairs you were attempting.
-
I had to wind in the threaded adjuster fully, after cleaning all the brake dust off, and then by trial and error, wound it out until the drum wouldn't turn, then backed it off a little.
The drums will be a tight fit, and aligning the shoes correctly is essential.
-
'70 S2.
I have the threaded adjuster fully out - thinking that this was the position of smallest diameter across the shoes. So, if the threaded adjuster needs to start off fully in, then that could be my problem. OTOH I have no difficulty mounting the drum over the shoes, so I doubt it's that.
The other thing I wondered is if the new pads are not the right size width-wise ...
-
If you have the adjuster on the backing plate then the shoes should be 1.25" wide. If the adjuster is part of the cylinder then the shoes are 1.5" wide.
-
If you have an S2 but shoes for a TCS, you will have interference problems.
If you have the correct 1.25 in shoes, check that they are snug back against the backplate, retained by the steady rests.
-
I've come to re-mounting the rear wheels. I have new brake pistons and pads installed on both. With the drum off, I can rotate the drive shaft easily by hand. When I place the drum in position, I can rotate the dtum, but it's a bit "graunchy", as if it's catching a little around the rim. When I then mount and tighten the wheel to the drum with the nuts, the wheel wont move at all!
..
Does the drum catch the brake shoes or the back plate?
If it catches the rear plate, maybe you are missing the outer spacer behind the hub?
Do not remove the hub until your are absolutely sure you mean it. But you should be able to see a 1/4''(?) spacer between the hub and the outer bearing.
BTW, you can tighten the drum without using the wheel (you might need some spacer material between the nuts and the drum). That way the wheel isn't in your way when trying to diagnose the sound/grinding.
-
I've come to re-mounting the rear wheels. I have new brake pistons and pads installed on both. With the drum off, I can rotate the drive shaft easily by hand. When I place the drum in position, I can rotate the dtum, but it's a bit "graunchy", as if it's catching a little around the rim. When I then mount and tighten the wheel to the drum with the nuts, the wheel wont move at all!
..
Does the drum catch the brake shoes or the back plate?
If it catches the rear plate, maybe you are missing the outer spacer behind the hub?
Do not remove the hub until your are absolutely sure you mean it. But you should be able to see a 1/4''(?) spacer between the hub and the outer bearing.
BTW, you can tighten the drum without using the wheel (you might need some spacer material between the nuts and the drum). That way the wheel isn't in your way when trying to diagnose the sound/grinding.
I have the correct 1.25" wide shoes, so now I am worried about the outer spacer.
The drum appears to catch the backing plate, which seems to indicate the drum is too far in when mounted.
Before I got the car, the PO had been messing with the rear suspension, so I am now unsure if I have all the bits. However, the car rolled freely on its wheels when I got it ?!
I'm looking in my workshop manual, but can't see a diagram showing the spacer. Does anyone have a photo?
Thanks!
-
Here is what the assembly looks like:
(https://c1.staticflickr.com/3/2938/33723232936_e11884f6ed_b.jpg)
I am pretty sure there was no outer spacer when I disassembled the hub, so that's weird. If I pull the hub and add a spacer, then it looks like the hub nut would not have enough threads to properly engage, as the hub would be further out.
-
Not quite. The outer spacer fits over the plain, unsplined portion of the stub axle, whereas the hub can only fit, naturally, on the splined portion.
The outer spacer is essential in clamping together the hub, spacer, outer bearing, inner spacer and inner bearing. You are right, the nut doesn't cover the thread, but there's plenty of engagement.
It's a good job you discovered this, as if you'd driven with it like it is there's a very good chance of losing a wheel. You MUST fit the missing spacer.
-
By the way, it looks like your drum has been catching on the wheel cylinder.
Are you assembling with the correct grade of Loctite on the splines? I hope so, and you'll need considerable heat to get the hub off again.
If you look at RD Enterprises website, parts manuals, Europa rear suspension, the spacer is part No 18 on the diagram.
-
http://www.lotus-europa.com/manuals/s2parts/d/index.htm
Spacer #16
-
http://www.lotus-europa.com/manuals/s2parts/d/index.htm
Spacer #16
Sorry, I was reading the TC page. 16 it is.
-
Not quite. The outer spacer fits over the plain, unsplined portion of the stub axle, whereas the hub can only fit, naturally, on the splined portion.
The outer spacer is essential in clamping together the hub, spacer, outer bearing, inner spacer and inner bearing. You are right, the nut doesn't cover the thread, but there's plenty of engagement.
It's a good job you discovered this, as if you'd driven with it like it is there's a very good chance of losing a wheel. You MUST fit the missing spacer.
Thanks! No chance of being able to drive it like this as the wheels wont turn :))
I pulled the hub off: here's a photo.
(https://c1.staticflickr.com/3/2925/33647935881_f3ef0bb1b8_b.jpg)
There is no spacer apparent - should it be between the hub and the bearing housing (where the orange ring is)? How thick is the spacer? I wonder if I can turn one on my lathe.
-
The orange ring is an oli seal and I aasume that the steel ring inside it is the inner ring of the hub bearing. The spacer is the same OD as that bearing inner ring.
It looks to me as though your stub axle is too far inside that bearing, because I think the plain portion of the stub axle, i.e. inboard of the splines, should protrude from the bearing. The spacer sits between the hub and the bearing inner. I'm not sure of the dimensions, but it is usually recommended that they be hardened and since you can buy them from regular suppliers I don't know why you'd make them.
I mentioned earlier about using Loctite 35 or modern equivalent on the splines. I see that's only mentioned in the TC manual, but I'm pretty sure it's recommended for earlier cars too. Maybe someone could comment?
-
The orange ring is an oli seal and I aasume that the steel ring inside it is the inner ring of the hub bearing. The spacer is the same OD as that bearing inner ring.
It looks to me as though your stub axle is too far inside that bearing, because I think the plain portion of the stub axle, i.e. inboard of the splines, should protrude from the bearing. The spacer sits between the hub and the bearing inner. I'm not sure of the dimensions, but it is usually recommended that they be hardened and since you can buy them from regular suppliers I don't know why you'd make them.
I mentioned earlier about using Loctite 35 or modern equivalent on the splines. I see that's only mentioned in the TC manual, but I'm pretty sure it's recommended for earlier cars too. Maybe someone could comment?
I think they are $30 a piece from Dent, so making them seems an economical alternative. But if they need to be hardened steel, that might be a problem.
Yes, I was using the correct Loctite on the splines, but didn't need any heat to break them free with the three prong puller.
If the stub axle is too far inside the bearing, why might that be? And how can I fix it? Somehow by pushing the bearing assembly towards the gearbox?
Thanks again!
-
This is from Tim Engels in the knowledgebase regarding the spacers:
X046D0148Z
2.125" +/- .010 long.
All models from the S1 up to but excluding the Twin Cam Special.
X074D0215Z
2.000" +/- .005 long
Twin Cam Special only.
The outer spacer is
0.375" long
All three OEM spacers are basically 1.5 OD / 1.25" ID steel tube parted off
to length and used as is... no heat treating.
1.500" OD (can be much larger
0.125" Wall
1.250" ID
It's a sloppy fit over the shaft and a more snug slip fit would be better.
(Shaft Journal OD = 30mm = 1.181 inch)
The ends of all spacers must be parted square and true
The inner spacers would be easier to center if they had a smaller ID that
was more of a slip fit on the shaft journal. The stock ID is just a
function of using common, off the shelf, thick wall tubing and parting it
off, and not a critical "right" fit. If I were making my own spacers,
I'd be inclined to spend a bit more on materials and machining and go for a
smaller ID and better fit on the shaft.
And the OD could be larger since there's nothing surrounding it. But
anything larger than the contact face of the bearing's inner race would just
be dead weight.
To keep the spacer from crushing under load and relaxing the clamp force
created by torquing the hub nut, the stress in the spacer must be kept
below it's compressive strength limits. That can be done by hardening the
spacer to raise it's limits, going to a higher strength alloy to raise the
limits, or thickening the wall to increase the cross-sectional area to
reduce the stress. Of course, thicker is heavier and not in keeping with
Chapman philosophy..Chapman philosophy..<WBR>. but not a
OEM spacers were nothing fancy and did have a tendancy to crush under load.
They could benefit from hardening. A better alloy steel would also help.
4130 or 4140 hardened would be an improvement. The best material would be
the same as used in the bearing race, but that would be overkill for the
job.
Later,
Tim
-
Strip the rear axle down and make sure the missing spacer isn't inside.
-
Well, Tim knows his stuff so you can make the spacers if you like.
The amount by which the stub axle protrudes from the upright is determined by how far it's pushed in. The inner bearing is relatively free to float in the upright, until the assembly of hub, spacer, outer bearing, spacer and inner bearing is tightened up. Even then, it's not located along the axis of the stub axle, that is done by the outer bearing.
If you have a bit of tube long enough to slip over the splines, try tightening with the hub nut and see if you can pull the stub axle out a bit.
-
Here are some photos of my tear down on my 72 TC. You can clearly see the spacer.
-
The photos are really helpful - thanks! Do you have a photo with the outer bearing removed, by chance?
I'm coming to the conclusion that I have the outer spacer, but it's pushed into the upright.
-
If I understand you, I don't think that could happen. There is a spacer between the two bearings in the housing and the outer spacer is running on the inner race of the outer bearing. If the outer spacer was pushed into the upright, it would have to do serious damage to the outer bearing.
-
I was just thinking the same as BDA. It's not possible for the spacer to get pushed past the bearing unless the bearing is destroyed. And then you have the larger spacer between the two bearings. There is no way for the spacer to move into the bearing carrier.
-
OK, yes that makes sense. The inescapable conclusion is that I'm missing the outer bearing :-\
I've ordered some steel 1.5" OD 1.25" ID stock tubing, so will try to first make a sleeve with that to go over the splines and allow me to tighten with the hub nut against the bearing, as Roger suggested. I'm hoping that this will push the stub axle out a little, giving more room for the outer bearing, which I can also fabricate from the stock tubing.
That's the plan, anyway!
-
FWIW, VW Beetle spacers can be used, already hardened. A lathe or careful grinding gets them to size. (On a TCS)
-
I would stick with a hardened spacer rather than plain steel tubing.
-
I would stick with a hardened spacer rather than plain steel tubing.
I agree! And I think you need to review your use of Loctite. The stuff you put on the splines when you finally assemble the whole is type 650 from memory, and you certainly need heat to get the hub off after it's set.
-
1/8" wall tubing is not going to make a spacer that can hold up under 150 ft/lbs of torque.
I would again recommend taking the upright completely apart to make sure nothing else is amiss.
The proper loctite to use is 635. It is slow setting so you have ample time to assemble things before it sets.
-
635, that's what I meant. Thanks jb.
-
1/8" wall tubing is not going to make a spacer that can hold up under 150 ft/lbs of torque.
I would again recommend taking the upright completely apart to make sure nothing else is amiss.
The proper loctite to use is 635. It is slow setting so you have ample time to assemble things before it sets.
But 1/8" wall tubing is what the factory used, no?
-
Yes, my point exactly. Use better steel and thicker walled!
-
There is/was a chap in the US who makes replacement stub axles for single-seat race cars from the 60s which used the Imp/Minx rear wheel set-up. Here's the spacer he supplies:
https://jbcollier.smugmug.com/Lotus-Europa/i-BCMxN3J/A
You have to machine it to suit your application but it is quite the step up from the piece-of-crap, thin-wall, mild-steel, and-even-f-ing-seamed, tubing that Lotus used. The Lotus spacers are so weak that Lotus specified replacing them every time the rear wheel bearings were serviced.
-
Here are photos of the stub axles mentioned above:
https://jbcollier.smugmug.com/Lotus-Europa/i-cQpwGW8/A
https://jbcollier.smugmug.com/Lotus-Europa/i-qpK59M9/A
-
There's a set available on ebay here: http://www.ebay.com/itm/Lotus-Europa-TCS-rear-hub-bearing-spacer-Twin-Cam-Special-TC-S2-/222075472524?hash=item33b4baca8c:g:exIAAOSwJQdXAv3A&vxp=mtr
All the usual disassociations apply (i.e. I don't know the guy)
-
Thanks guys ... I bought a couple of the Ebay ones.
-
I received the outer spacers, and have been test fitting them. With the spacers installed, there is no longer any contact between the drum and the backing plate, so the wheel turns freely. Hoorah :-)
However, there are now minimal threads exposed for the hub nut to engage with, especially if I use the D foldable washer with the nut.
Here's a photo without the D washer:
(https://c1.staticflickr.com/4/3939/33922832602_5532c5ee56_b.jpg)
It seems to my inexperienced eye that the stub axle isn't long enough. I wondered whether the bearing assembly had shifted down the stub axle because the suspension has been fully extended due to the car being on jack stands for so long. So a couple of days ago I lifted it up with a jack to see if the axle would move outwards or not - but this doesn't appear to be the problem.
I may have to resort to tearing down the whole assembly, as jbcollier advised, but I'm really loathe to go to all that trouble (it looks like a major operation) if it's not necessary.
Can anyone think of what the problem may be? What is baffling me the most is that when I got the car I was able to push it around the yard without issue: the rear wheels turned freely, and I'm certain that there were no outer spacers on them!
-
The problem may be the previous owner's messing about, as you put it.
You don't know what's inside your hub carrier, and I'd be nervous about that if it were me, and I would definitely take it apart and find out. You've done the hardest part of the job since your hub is free on the stub axle. Now, to strip it you need to drive out the roll pin on the inner u/j, remove the trailing arm from the hub carrier, take off hub and outer spacer, and it should all come apart. Nothing difficult.
-
My guess is still that you will find the missing spacer inside the hub.
-
OK! I'll take it apart. I recently replaced the roll pins, so know how they work ... so to strip it, is the following procedure good:
1) punch out rollpins on inner u/j
2) remove trailing arm from bottom of upright/bearing carrier
3) remove outer spacer
4) remove hub
At that point should the axle pull out of the bearing carrier (towards the center of the car) easily?
-
Not quite. Review the workshop manual (http://lotus-europa.com/manuals/s2work/d/s2d.pdf). Disconnect the half shaft from the tranny output shaft. Take the hub off the stub axle. This might (should) require heat to break down the loctite down (don't forget to get new loctite to use in reassembly - Loctite 35 or modern equivalent for splines). It will also require a puller. Pull the stub axle through the upright. Disconnect the shock from the upright. The upright can now be unbolted from the radius arm. Chances are that whatever the problem is, it will become obvious in this process so you may not need to take the upright off the radius arm. I believe that the bearings in the upright are a weak point on the S2 in part because the spacer between the bearings is not hard enough. At this point, it might be a good idea to get some hardened spacers from one of the usual suspects. This would require taking the upright off the radius arm by undoing the eight bolts (four on each side of the radius arm).
I think I've gotten the major steps and issues correct, but someone more familiar with S2s might want to check me and correct me if needed.
-
I extracted the half-shaft complete with stub axle. I think I see the "missing" outer spacer in the upright, but I'm not sure (and haven't tried to extract it yet):
(https://c1.staticflickr.com/4/3935/33975936811_4261846e5a_b.jpg)
Here's the stub axle (sorry for poor focus):
(https://c1.staticflickr.com/3/2811/34106372245_1019173089_b.jpg)
-
You mean there's an inner spacer AND an outer spacer in there? Or just an outer? I can hardly believe the former, and the latter is just plain daft.
-
You mean there's an inner spacer AND an outer spacer in there? Or just an outer? I can hardly believe the former, and the latter is just plain daft.
I don't know yet - haven't had a chance to explore further. My understanding is that in the carrier there are two bearings separated by a (rather long) spacer. The outer spacer fits over the splines between the hub and the hub carrier. Should there be another spacer, between the inner bearing and the u/j on the stub axle?
The parts diagrams are not very readable, and I've searched through all the photos in the Yahoo Lotus group looking for a good image, but drawn a blank.
-
Update: I looked closely inside the carrier, between the bearings at each end there is a long spacer and what appears to be the MIA outer spacer!
So, now I just need to extract the outer spacer, somehow.
-
That's right. There should be a spacer between the bearings and a spacer between the hub and the bearings (i.e. upright). The hub has a counter sunk surface on the outer bore and Dave Bean (I believe) sells a 'conical' washer to go between the hub and the nut to help center it. I don't think that was ever a stock bit. I don't believe there are any other spacer type things.
I don't know if this picture from the TC shop manual will help, but it might...
-
Check the manual, but IIRC, you heat up the upright with hot water to get the bearings out. How old are your bearings? It might be a good time to install new ones.
-
kudos to jbcollier correctly predicting that the MIA outer spacer was inside the hub carrier! Why the PO put it in there is anyone's guess.
I was able to gently tap out the inner bearing with a drift placed against the outer spacer in the hub carrier - so that was convenient! Out came the inner bearing, the outer spacer and the inner spacer (in that order).
(https://c1.staticflickr.com/3/2880/34127988835_318ec15f57_b.jpg)
Now I suppose I just need to replace the inner spacer and press in the inner bearing and its cover, before re-inserting the stub axle. The inner bearing looks good, and the outer bearing appears to be relatively new.
-
Amazing! I don't know how he could have fit it in there!
-
The outer axle bearing journal is no good and the splines may be damaged also. It also appears the inner bearing was not seated fully and not pressed onto the shoulder. Check the length of the long spacer, it should be 2"
-
The outer axle bearing journal is no good and the splines may be damaged also. It also appears the inner bearing was not seated fully and not pressed onto the shoulder. Check the length of the long spacer, it should be 2"
Yeh, the inner bearing couldn't meet the shoulder as the PO had placed an outer spacer in there preventing it!
The splines look serviceable to me for the time being.
The inner spacer is a tad over 2", which is correct I believe.
-
The inner bearing does not seat, it provides no axial location.
Since you don't have a TCS, your spacer should be 2.125" long.
I'd clean up the outer journal with a bit of fine emery, then look again keeping in mind that the outermost part, just before the splines, is where the outer spacer sits.
As for the splines, since you are going to fill them up with Loctite, they probably are ok. They will only wear further if they chatter in the hub.
You are going to use the correct Loctite I hope! An earlier comment you made about removing the hub without heat doesn't suggest the correct grade was used then.
-
having followed this post for a few weeks now I'm going to strip mine down again in the coming weeks. This was one of the few jobs I didn't do on my restoration project and took the parts to my local garage to do the bearings and UJs. I have no doubt he didn't use locktite.