Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: StephenH on Wednesday,February 12, 2014, 05:47:18 PM
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Having just replaced the uni joints on my S2 I notice there is some play in the R/H splined yoke.
On the R.D. Enterprises website there is available some 'Rear Axle Shims'.
http://www.rdent.com/ (http://www.rdent.com/)
None on my car and the yokes don't appear to have a surface designed to take a thrust washer.
Are these shims fitted to all Europas and what is the rule of thumb for use and clearance?
The manuals available do seem to show a spacer or thrust washer, but as I said, the yoke doesn't appear designed to take one (no flat machined surface on the end of the yoke).
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AFAIK they all have them and if yours doesn't then it's either unusual in not needing any, or it's been wrongly assembled.
When I bought my car I was quite friendly with a Lotus specialist and aside from selling parts he was very helpful about telling you about weak points he'd found. The driveshaft shims were one thing he mentioned specifically and how I should always make sure that the yoke was shimmed tight to the inner surface. He was so fanatical about it that he'd check customers cars when they came in for service and I remember he said it was a "service item" as far as he was concerned.
I've never thought too much about the design because Chris was so adamant about it, I think it was something to do with the load on the diff bearings/driveshaft in cornering but I can't remember off hand other than he predicted dire consequences for getting it wrong.
Ever since I've just fitted as many shims as would fit, I simply pack shims until the roll pin holes are just fractionally "too tight" and then press the pin in place. Once the roll pin is pushed in fully it's a very rigid assembly. I don't know if that's right or not, but it's worked for me.
Nothing special about the shims, you can buy similar things at most engineering suppliers.
Brian
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Thanks, sounds about right.
I have been poking around tonight.
Would say the L/H side probably doesn't need any shims but the R/H probably does.
Would explain the tiny bit of play that shows up on that side and probably why some wear is apparent on the splines on that side.
Now that I have pulled the rear-end apart once and shoved it back together it should be a breeze to get it right.
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Anyone happen to have the shim ID and OD dimensions handy so I can chase up locally?
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The shimming ensures that the side loads go directly into the diff's carrier bearings. If there is free play the load goes through the side and spider gears first and they are not designed to take side loads and will fail.
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When I needed shims I used blower shims for a Detroit Diesel inline 71 available from a nearby trucking garage and very cheap. You can check them out here.
http://www.detroitdieselpartsdirect.com/search.aspx?searchTerms=5150856 (http://www.detroitdieselpartsdirect.com/search.aspx?searchTerms=5150856)
The part numbers you need are:
5150372 - shim .002"
5153938 - shim .003"
5150855 - shim .005"
5150856 - shim.010"
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George, great info on the DD part numbers. I believe the three Lotus vendors supply shims of only two widths.
For how to shim and why shimming is necessary, check the Knowledgebase under "roll pins" for all the posting by Tim Engle. He gives the most clear explanation for why correct shimming is required for the output axles.
Joji Tokumoto
Fallbrook, Ca
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I should have mentioned the Knowledgebase too, Joji. It's a great resource and it's probably where I got the idea for using the Detroit Diesel shims.
http://www.lotus-europa.com/ekb.html (http://www.lotus-europa.com/ekb.html)
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Thanks all, job done.
Finding the DD parts isn't easy here, joy of having a small market, you can't just pick stuff up across the local counter.
For fellow Australians I found an online place located in Queensland that supplies a range of shims.
Ordered a selection last night to keep on hand for future use.
http://www.smallparts.com.au/store/partscombined/precisionshimwashers/ (http://www.smallparts.com.au/store/partscombined/precisionshimwashers/)
25mm ID / 35mm OD seems to do the trick.