Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Adde on Sunday,September 03, 2017, 11:13:44 AM
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Hi
I need some advise to diagnose a "slip/movement" in my right rear wheel.
1) I have a slip/movement in my wheel at (12) twelve o'clock if I put my jack right under the suspension (see fig 1)
2) But the slip will begone if I instead put the jack support right under the radius arm or what its named. (See fig 2)
Why is that? Where is the slip? Wheel bearing or something, else?
BR/
Adrian
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If the movement is only at 12 o'clock and not at 3 and 9 o'clock, then I would not suspect the wheel bearings. I'm thinking that jacking on the upright gives a pivot support that jacking on the radius arm does not. I would look at the half shaft - u-joints, the attachment to the output shafts of the tranny, and their bearings or adjustment - most likely the tranny bearings.
As an aside, I would not jack on the radius arm. You won't likely damage the arm, but you could scratch paint off or create little dents. And jacking on the upright seems a bit tedious. I recommend jacking at lower suspension attachments on the tranny, the tranny itself, or the rear hoop if it's handy.
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Hi
Thanks for the very quick response, I will make a new attempt to pinpoint the reason for the slip/movement tomorrow. (And I will then use the rear hoop as jacking point.)
BR
Adrian
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I would also suspect the uj's or even pay on the output from the gearbox. I.e. Not properly shimmed gearbox output shaft. By jacking on athe radius arm you are locking out any other play that the bearings.
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I would also suspect the uj's or even pay on the output from the gearbox. I.e. Not properly shimmed gearbox output shaft. By jacking on athe radius arm you are locking out any other play that the bearings.
As BDA says, wheel bearings normally show play at all round so my vote is another one for the gearbox shimming then UJ's. How much movement do you have there, is it just by feel or is it noticeable ?
I suspect we've all lifted the car as you've done (I admit I've got a small bottle jack + wood block that I use under the radius arm for a quick check with brake pads, etc) but there are so many potential wear points on the rear suspension that it's probably best to go off the rear hoop and let the whole lot hang free. Otherwise you can end up masking one or other places.
Brian
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I didn't think about the shims, partly because I don't need them, but does the tranny need to be reshimmed occasionally? I would have thought that once it's done, it's done.
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Recommend you have a friend look at the driveline while you rock the wheel back and forth to see if he can detect any movement. Could a broken yoke pin cause movement?
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I didn't think about the shims, partly because I don't need them, but does the tranny need to be reshimmed occasionally? I would have thought that once it's done, it's done.
In my experience, yes, I've never found wear and although I've replaced old shims with new I very much doubt the totals have changed in years.
But I'm mindful of Chris Foulds who told me early on that it was a service item which they always checked when a Europa came in for any sort of routine service. Maybe it's in case the pins break or maybe just because the consequences of not having such a simple thing right will lead to more expensive problems, I don't know because he didn't elaborate. But he made an impression on me that's hung around to this day !
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That's what I thought. I agree with you that they (and the pins) should be regularly checked - especially when there is slop found in the rear suspension.
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Back from the garage where I now have...
1) disassembled the outer drive shaft (stub axle) from the wheel bearing housing and the bearings seems to be new and when I feel with my fingers is feels tight and good. (I bought the car for about 1 year ago, and has been fixing with it since then, hence no real driving). I therefor don't expect the bearing to be worn any more.
2) However, I'm a bit suspicious if there is a gap between the bearing and the axle, i.e if the axle has been too much grind. I tried to measure the axle and it then seems to be like 29.7-29.8mm instead of 30.0mm, BUT I'm not sure that my vernier caliper is very accurate, hence I don't trust it fully. (I need to get a better vernier caliper for a second opinion).
If there is a gap between the bearing and the axle, is there any way to fix it then?
3) I have also been thinking of the U-joint and if that can be the reason. How tight should these joints be, supper tight or can there be some movements? This need some more investigation.
(If its the U-joint, would these fit? "http://www.mevspares.co.uk/UNIVERSAL-JOINTS-x2-Lotus-Europa-Driveshafts.html?main_cat=1288&child=0")
4) The gearbox feels rather solid, no major axial or radial movements as far as I can tell. However there is some rotational movements, but I assume that is normal as the gear teeth is not in contact in both rotational directions, or should they?
I appreciate all your kind and constructive feedback. This forum is great and just what I need if I ever should get my S2 68 out on the road.
Best Regard
Adrian
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There should be no play in your u-joints. If you need new ones, look for these: Hardy Spicer K5 GB161 [/size](TR3, TR4, TR4A, TR250, TR6, Volvo 164) for a TC. For an S2, look for these: Hardy Spicer K5 GB150, Borg Warner 114 514, Neapco 1-300 (TR Spitfire).There will be some rotational movement due to the gear lash. There shouldn't be any axial movement at the tranny output shafts.There are products that can "make a shaft a little bit bigger in diameter" but I really can't give advice about that. Maybe someone else here can address that or a machinist should be able to help. While the upright is apart, you should make sure you have hardened spacers (or just buy a set if there is any doubt. You should also get the proper Loktite for fitting the hub to the shaft. The manual tells you but you may have to convert to the more modern product. It's NOT regular red Loktite.[/color]
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2) However, I'm a bit suspicious if there is a gap between the bearing and the axle, i.e if the axle has been too much grind. I tried to measure the axle and it then seems to be like 29.7-29.8mm instead of 30.0mm, BUT I'm not sure that my vernier caliper is very accurate, hence I don't trust it fully. (I need to get a better vernier caliper for a second opinion).
If there is a gap between the bearing and the axle, is there any way to fix it then?
3) I have also been thinking of the U-joint and if that can be the reason. How tight should these joints be, supper tight or can there be some movements? This need some more investigation.
(If its the U-joint, would these fit? "http://www.mevspares.co.uk/UNIVERSAL-JOINTS-x2-Lotus-Europa-Driveshafts.html?main_cat=1288&child=0")
Hi Adrian,
I've no idea what the shaft measurement should be but yours doesn't sound too far away. There are numerous "bodges" for getting round minor wear which range from using a gap filling material often sold as "Bearing Fit" (similar to the stuff used on the axle splines) to building it up by metal spraying. Incidentally, that axle looks clean, have you cleaned it for the photo or was it assembled without Loctite ? Loctite is very important there....
The U-Joints on my car are pretty solid. They rotate freely of course but in terms of movement, well I can't feel any. With the driveshaft forming the top link, I wouldn't expect any there. Incidentally, those U-Joints seem very cheap, they may of course be perfectly ok but at a fiver apiece it would raise my suspicions as to where they were made and what the quality is like.
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Hi
1) I have not cleaned the splines, i.e. it was assembled without any Loctite. Can that cause the gap/movement that I felt in the wheel, or is it only to prevent wear of the splines? What Loctite should I use for the splines and for the contact between the axle and bearing?
2) I also plan to change the UJ, and need therefore to disable the driveshaft from the gearbox. Is it just to pull out the shaft from the gearbox with the right amount of force or are there any tricks?
Best Regards/
Adrian
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Here's the reference from the TC workshop manual (I couldn't find any reference to loctite in the S2 manual):
2. BEFORE fitting the rear hubs and to ensure a positive fit between the hubs and the outboard drive shaft, ensure that both the hub and drive shaft are free from grease and dirt. Spray the mating surfaces with Locquic primer grade 'T' and allow to dry. Apply Loctlte 'High Strength Retaining Compound Type 35'.
As I said before, that type of loctite may have been superseded so you should ask for the modern equivalent.
In spite of the fact that the S2 manual doesn't mention it, if you have an S2, I would still use the loctite. I don't think not having the loctite would cause the slop you were seeing presuming the hub nut was torqued at all.
The u-joint is pinned to the output shaft. After that, it just slides off.
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The modern equivalent is 635.
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Hi
Some updates regarding my progress the last week (1, 2), and some further questions regarding shimming the drive shaft into the gearbox (3).
Sorry for the very long mail, but I have so many question marks.
Since last time, I have:
1) checked the bearings in the rear hub and the seems to be in good condition. Now reassembled with an looctite equivalent on the bearing and splines.
2) Changed the universal joint as there was a very small clearance/movement axial in it. I must say that the UJ was not that easy to remove, it took me quite some time.
3) I have now assembled the drive shaft again, and can now conclude that there is an axial movement (end float) in the shaft connected to the gearbox, as some of you already suspected earlier in this thread (BDA, and buzzer). As I understand it this is not unusual, and something that can be fixed through shims, correct? I have tried to search for guidance in earlier threads and found some useful info, but I still need some more guidance.
Is it correct that I can fix this through shims and that it can be done without disassemble the gearbox except from the diff nut (fig 1)?
What is the the correct procedure for shimming the drive gearbox?
1) Remove the drive shaft.
2) Remove the diff nut (where to get the tool, can it be homemade or handled in any other way?)
3) Add shim(s) outside the spacer (can I get universal shims with ID 25mm OD 35mm, as last post in http://www.lotuseuropa.org/LotusForum/index.php?topic=618.0 (http://www.lotuseuropa.org/LotusForum/index.php?topic=618.0))
4) Reassemble everything
5) See if the axial movement is gone, if not start over from (1) and add another shims.
Is this the correct way, or should it be done different?
Can I decide what's decent number (total thickness) of shims without reassemble everything in between?
How tight should it be, as tight as I can get it?
Isn't the contact face between the gears in the diff extremely important for the wear (i.e. needs accurate measurements), or can it be handled in this rather basic method?
What will/can happen if I don't fix this at once?
Some figures borrowed from "http://www.lotus-europa.com/manuals/misc/transmission/diff_nuts.html"
Best regards
Adrian Dahlquist
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Having done u-joints and reassembled the upright including using hardened spacers and torquing the axle nut and locking it, other than the differential bearings, the only other place to look is shimming the u-joint yoke on the tranny. I THINK this is the most likely problem you're experiencing. It is certainly the easiest to address so I think you should fix this and if it doesn't fix it, go to the tranny. The shims are available on your side of the pond from Richard at Banks, SJ Sports Cars, and other vintage Lotus outlets. The idea is to stuff enough shims between the yoke and tranny so there is no slop after you install the roll pin. You don't have to take the differential nuts off (rdent.com has a tool for the diff nuts if you end up needing one). You should get more than you think you'll need.
In steps:
1. take the drive shaft off from the output shaft of the tranny (it sounds like yours is already off the car).
2. put a couple of shims over the output shaft, put the u-joint yoke back on the output shaft and sight through the roll pin hole to see if the hole in the output shaft lines up with the hole in the yoke.
3. add or take away shims till the holes line up. (I might add an extra thin shim here.)[/size][/font]
4. install the roll pin. If the thin shim made it so the pin won't go into the output shaft, take it out and try again. It should fit now.
5. test for play. adjust if necessary.
If that doesn't fix your problem, you may have a problem with your bearings which might imply a problem with the crown & pinion back lash. If that's the problem, things get a little more complicated. Hopefully the shims fix it.
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Get the tool to undo the castellated ring nut from Banks.
Don't try and undo it with a hammer and chisel or you will break it, and replacements are made from unobtainium.
Or if you are passing by in Norfolk you can borrow my tool.
Alex in Norfolk.
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Ok, where EXACTLY do you have axial play?
Does the half-shaft move in and out?
With the half-shaft removed, does the splined output shaft move in and out? If so, how much?
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If the half shaft is locked to the differential output half with the roll pin, won't the remaining sources of axial movement be the U-joint at the inboard side or the output shaft at the differential or possibly a worn roll pin hole or broken roll pin?
According the Renault manual (I'm using the NG manual for reference), the differential adjusting nuts are turned in until all end play is removed and the differential still turns freely. If there is output shaft end play could the differential adjustment nut been previously misadjusted.
Before doing anything else have a second person move the wheel back and forth while you pinpoint where the movement is.
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If the output shafts have axial play, then the diff gear shim/spider gears have worn. This usually results from insufficient shims between the half-shaft and the seal run. You have to strip the transaxle to repair. Very minor amounts of output shaft axial movement is ok.
The large side nuts hold the seals but their primary function is adjust the diff's crown gear position and bearing preload. This CANNOT be adjusted in situ. You have to remove the transaxle and bell housing to set it up properly.
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I should have mentioned that the manual requires the differential adjustments have to be done with the transaxle removed and cases split. It's not a job to be done lightly as pulling the transaxle is a pain in the ass. You really need to identify the source of the movement first, you don't want to get into the transaxle unless you narrow it down as the source.
I'm doing the differential bearing preload and backlash adjustments for the first time with a 336 transaxle in my Manual transaxle/driveline class. Really looking forward to learning about this as I have another spare 336 disassembled on my work bench as a practice run.
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Thanks for all the replays, really appreciate.
I need to digest the information and think through this some more before deciding what to do next as I haven't been able to determine if the movement is the UJ sliding on the "tranny" axle or if its the tranny axle itself. I was just in my garage making an attempt, but was not able to remove the UJ from the tranny axle (due to the loctitet I added earlier this week). Which I, however, think indicates that the movement is in the tranny axle, as I otherwise likely would be able to remove the UJ.
I have also been thinking about whether this minor movement will be any problem in reality, or not. My thinking is that this movement will only be present when the car is standing on the jack, and unload the suspension, hence removes the compression force on the driveshaft. But, when the car is standing on the ground, will the suspension be compressed and and the driveshaft pushed against the tranny, as it also acts as the upper linkarm,
It is hard to tell how big the axial movement is. I captured a video with my cellphone when the car is on the jack, see https://youtu.be/Jm_Uz5Prbaw (https://youtu.be/Jm_Uz5Prbaw).
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It is hard to tell how big the axial movement is. I captured a video with my cellphone when the car is on the jack, see https://youtu.be/Jm_Uz5Prbaw (https://youtu.be/Jm_Uz5Prbaw).
If I'm viewing that correctly, my initial impression is that you have far too much movement there. My car is rock solid at that point, not even a "feel" of movement, whereas that looks like it's physically moving. 1mm ?
Assuming the roll pin isn't broken (it doesn't look like it) then there's either something adrift with the bearing/diff settings or a lot of shims missing. I can't tell you what I have in the way of shims on mine but I'd guess it's no more than 2 or 3 shims at between 0.005" to 0.010" thick.
I really wouldn't drive the car in that condition. at the very least I'd remove the roll pin and insert shims to take up the play.
Brian
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That movement is unacceptable and since you have a roll pin installed, and assuming it's not broken, it is because of slop inside the tranny. You're going to have to take the tranny out to take care of it. I'm no expert, but I would say that at a minimum, the bearing pre-load (and thus the crown/pinion back lash needs to be adjusted), but I think more likely you have issues with the bearings themselves and they will need to be replaced. Those bearings not only take the loads from the crown gear but also the upper lateral suspension loads.
I wonder if you've misunderstood about the loctite? It should be used on the splines of the stub axle where it mates to the hub (which holds the brake drum and wheel studs). There is none needed on the output shaft ("tranny axle") to u-joint yoke joint nor is any desired for the reason you found - it makes taking the half shaft off the output shaft a lot more difficult and it doesn't add anything. It will require heat to break it loose.
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OK, too much play and insufficient shimming. Do not drive it.
Busy right now but will post a detailed explanation later.
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I really wouldn't drive the car in that condition. at the very least I'd remove the roll pin and insert shims to take up the play.
OK, too much play and insufficient shimming.
When I had my tranny out, I didn't check for lateral movement in my output shafts (just the crown/pinion back lash and bearing pre-load) so I don't have direct experience with this. And since I have a twin link rear suspension, I don't have to concern myself with shimming the u-joint yoke in the first place. I always thought that the shims were there to keep the roll pin from taking the suspension loads. So maybe my understanding of this is flawed.
I look forward to your comments, John.
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and I thought if the shims between the drive shaft and the gearbox were insufficient, the roll pin would just break.
I think it may be a problem with the shimming of the diff, but will let others with better knowledge of pre-loads, diffs, planet gears, and the mystery of the correct differential building explain.
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It seems as I have a bigger problem then I was hoping for. Lets see if anyone has some good advise how to solve it.
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Hi
I want to start by apologizing for possibly using the wrong terminology or misunderstanding it all.
But, what are you opinion about this:
I'm thinking that maybe the issue is a too big backlash in the "spider" gear connected on the tranny axle where I see the movement. (That would then also explain the rotational movement (Backlash) that I mentioned in my first post).
If so, can it be worthwhile to try to tighten this by first tighten the diff nut until the axial and rotational movement is gone and then just lose the nut slightly to get some backlash in the gear?
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No. You must adjust the crown/pinion backlash as well as the bearing pre-load with the tranny out of the car. These adjustments are not something you can do by just snugging the diff nut.
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Ok, thanks.
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I think John is the most knowledgeable of us on this topic and as I've never pulled this type of gearbox apart I think I'd wait for his input before making your final decision on what to do.
Personally I would be tempted to fit shims and see how it all feels (play and backlash) before stripping the gearbox. If there is serious wear present then I'd expect it to feel rough or noisy even when shimmed correctly. Then I wouldn't feel so bad about having to remove the gearbox from the car.
I'd suggest that because it's easy and can be done in an hour or less whereas removing the transmission is a much bigger job. Drive out the roll pin (make a punch tool if need be from steel rod) and with the car supported on axle stands on the chassis and the suspension free you should have enough movement to slide off the yoke and drop a few shims in. Don't rotate the stub axle or yoke so you keep the holes aligned and know that the new roll pin should fit perfectly.
My method of shimming was crude; I guessed the first attempt and looked if the holes line up with the yoke pressed hard against the gearbox. If they don't, add or remove shims until it looks right. It's always been a tough job to drive the roll pin back in place with no play present.
As an aside, yet again I'm impressed with the technology we have today and this interweb thingy. Even 20 years ago there would have been email debates over what was actually wrong and yet your phone video sets it out clearly. I think this computer thing might just catch on y'know..... ;)
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Typically there is NO perceptible axial play on the output shafts. You have a lot of play.
Have a close look at the image you posted with the arrow to the diff. The arrow points to the diff side and spider gears. Immediately to the left of the left side gear is the shim which controls the output shaft's axial play. Here's another image:
http://www.rdent.com/manuals/europa/tcparts/transmission/FM.gif
The diff housing (incorporating the ring gear) is a solid assembly. The external nuts set the ring gear's position and bearing preload but would have NO effect on the output shaft axial play.
The shimming people are talking about is the placement of shims between the pinned half-shaft yoke and the collar which the seal runs against. The seal collar presses against the very large diff housing and its bearings which have no problem carrying the suspension's loads. Without these shims, the suspension load goes to the internal side and sider gears. These are not up to the task and quickly wear giving the excess axial play you are experiencing. The play develops first, then complete failure.
Myself, I would remove the transaxle and repair the problem. This may involve just replacing the diff side gear shim, or fitting another unworn diff housing.
Mr E. TC is suggesting that you properly shim the half-shafts. This will correctly apply the suspension loads to the diff housing from the internal gears. The internal shim/housing/gears will not get "better" but they will stop getting worse. This may be worth pursuing and provide a lasting fix. Unfortunately it is impossible to know for sure without stripping the transaxle and checking the diff's condition.
So, now it is your decision which way to go.
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Or go to a twin link set up and not worry about pins, shims, and diff loading. Did mine 10 years ago.
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(part quote)
The internal shim/housing/gears will not get "better" but they will stop getting worse. This may be worth pursuing and provide a lasting fix. Unfortunately it is impossible to know for sure without stripping the transaxle and checking the diff's condition.
Can't argue at all with that John, whatever damage is done won't be fixed by externally shimming it correctly.
I have been puzzling over the video this afternoon while fixing my bike because to me there's a heck of a lot of movement and I kept thinking with that amount of potential wear on a gear or bearing we were into grinding bearings/gears that were shouting "fix me" very loudly. I had a failure on the diff of a Scimitar many years ago and although it sounded like the axle was about to explode, when I replaced it I was surprised how little misalignment made so much noise.
Which got me thinking along a different tack, could this have been assembled incorrectly at some point and not driven much since ? The lack of loctite on the splines got me wondering because that's a well known item so perhaps there's an element of improper assembly here as well. I'm curious if there has ever been any shims fitted, internally or externally ?
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Thanks, John! It's always an education when I read your posts!
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Hi
I removed the UJ today today to see if I could pinpoint the axial play to the output shaft.
But, with the UJ removed I was not able to recreate the axial play through pulling/pushing on the output shaft. I could feel some minor axial play, but not close to what was seen on the movie before. However I could not apply the same amount of force now, but I tried by both hand power and through putting a screwdriver through the pinhole to get better grip.
This makes me unsure about where the real play is, i.e. in the axle or in the UJ?. If it is not in the axle I can not really understand how the UJ should be able to move on the axle whit the pin properly installed through the axle and the UJ. (The pin fit is tight in both UJ and axle, but maybe the pin spring when the UJ don't have a solid support against the differential house? Probably just a wishful thinking of me but I will start by buying some shims and add these between the UJ and the nut on the differential to see how that works. There don't seems to be any shims on the UJ right now, see fig)
"The external nuts set the ring gear's position and bearing preload but would have NO effect on the output shaft axial play." Ok, then I will not touch the nut.
I will return with the results and most likely further questions, too. (for sure if I decide to disassemble the gearbox)
All your support is so appreciated!
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If you replaced the u-joints, the movement is not coming from them. From your video, it seems very clear that the movement is coming from the output shaft moving.
jbcollier is the expert in this area (and most others, too). I would prepare myself to follow his advice.
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Wrap the output shaft with a rag and grip it with vise-grips. That should give you enough grip. Rotate the diff and try in several different places. Hard to believe it is gone but you can't fix what isn't broke.
I quickly checked with my long-suffering wife and she assured me that I'm invariably wrong in all matters great and small. Seriously though, we are diagnosing over the "phone" so to speak, and it is not always easy to understand what is actually occurring. Lots of discussion and investigation is a good first step in any repair. As I tell my students in the mechanical classes I teach, I have just been making mistakes longer than they have.
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OK, to my mind its the shimming of the output shaft on the gearbox. In looking at the video that is your issue (assuming you have not shimmed the driveshaft yoke onto the output shaft but just fitted the roll pin, if you have shimmed correctly then its gearbox output bearings and the box has to come out)
The splined gearbox output shafts do have end float as the output bearings ride on the diff crown wheel which control the crown wheel backlash and bearing fit. The splined output shafts are a clearance fit inside this crown wheel housing and will have backlash from the internal differential gears.
IF there was no end float on the gearbox output shafts the shims would serve a different purpose. i.e. after fitting the roll pin there could be a gap behind the driveshaft yoke and the gearbox and you would feel no play. THIS IS NOT THE CASE! there is end float on the gearbox splined output shaft which the shims take up to ensure any load is taken on the output bearings and not on the internal diff gears and the roll pin and allow excessive driveshaft play, all of which are bad....very bad...
When fitting the shims follow the manual.
However, if after shimming the yoke onto the output shaft properly you still have float then its must be in the gearbox output bearings, which if this is the case you will find vertical movements too as these bearing are tapper bearings
hope this helps
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Generally diff side gears and spider gears are set up to be a "stiff" or "snug" fit. This means the diff gears will be a bit stiff to rotate (not the diff itself, but the internal gears). This will wear into a nice fit with minimal drag, good tooth contact, little stress to the gears and shafts and hardly any play. In and out play as shown in the video means that gears are moving around under load and during load/no-load transitions. The gears are under going considerable stress and tooth contact is not ideal.
In Europas this is caused by incorrect half-shaft shimming. Instead of the suspension loads being applied to the large tapered roller bearings supporting the diff housing, the load is going through the diff side and spider gears first. They were not designed for these loads and they will wear and fail.
Now the question is: Can he get away with just shimming the half-shafts correctly?
I don't know myself though, again speaking for myself, I would open it up and repair the diff.