S1 336-08 Transaxle LEAK!!!!!!!!!!

[My S1]

HELP!!!!!!!!!!  Well, just as I was enjoying a love fest with the Europa, a significant and constant leak magically appeared.  The transaxle oil is seeping out between the drive shaft yoke and the spacer ring and or bearing retaining nut.  WTF!  Have you guys experienced this problem?  Is it a tremendous undertaking to remove the yoke and replace whatever is supposed to seal the ring and nut?

[bjthomp]

There is a lip seal mounted inside the retaining nut. I think just about everyone has experienced it. One has to remove the axle from the transmission; remove the retaining nut; and remove and replace the seal. Then reverse the procedure. There are various techniques people have used to accomplish each step. I'll leave that to others. Considering that your car is not quite fully assembled, I would say it's not that big a hassle. But I've never found it pleasurable. 

[My S1]

bjthomp,  thank you for that.  I just found this old discussion on the forum;

https://www.lotuseuropa.org/LotusForum/index.php?topic=1384.msg12224#msg12224

Good to know I'm not the first guy to experience this horror.  I think I have a good idea of what is going on now however I would like to know from you guys:

1.   Is this a bench job or can I do it with the transaxle in situ?  Fortunately it is on the right side rather than under the silencer.

2.   What is involved with pulling out the half shaft?  Do I have to remove the upright and trailing link?

3.   There was allot of talk about RD's square seals and O rings.  What is the latest?  Where to source them?

4.  As my luck would have it, I have a scrap of 2-3/4" O.D. x 1/4" wall 6061 in the scrap rack so I can make a tool.  Does the bearing retaining nut unscrew by hand or do I need to attach a nut on the end of the tool for a rachet?

[314159td]

Did a rebuild on a 336 recently, I don't think this should be too bad.

1. Can do in-situ unless you have another reason to pull it (in which case, it's pulling the engine and trans as one unit)
2. I think you can get away with unbolting the front pivot, spring/damper assembly, and lower link. Then you can drive the two roll pins out of the transmission-side yolk and the yolk should slide off as you move the suspension arm outboard.
3 idk, I just ordered seals and o-rings by the size I pulled out. I find that less frustrating than combing the forums as long as you're careful and consider the various elements of the application - don't use viton seals here.
4. After removing the screwed in holding clip, I tapped the finned nuts loose using "Performance Tool W1270" with a normal length ratchet and then unscrewed them by hand. Ensure to mark the position before unscrewing.

Definitely clean up those fine aluminum threads on the nut and transaxle case before screwing them back in, and grease them! Aluminum on aluminum loves to cause problems and I believe it's also a leak path in this design.

[My S1]

314159td,  that Performance Tool W1270 looks like it will save me allot of trouble making the tool  I read somewhere that there is a special drift pin for the yokes (?) and also a special thread cleaning tool.  I can see that this leak will drive me into restoring the whole damn rear end with powdercoating etc.  Don't be surprised if I'm asking dumb questions for several months.

I sure wish there was a more concise and detailed shop manual available.  The official Europa manual skips over so many details that would make things clear to the novice. This manual was decidedly written by Mechanics and for Mechanics, and not for the weekend mechanic wannabees like this knucklehead.  By Mechanics, I mean brilliant tradesmen who prepare race cars and/or repair cars for a living. 

[BDA]

A regular 3/16" punch is usually enough to get the pin out enough to grab with pliers but these (https://www.harborfreight.com/5-piece-long-drive-pin-punch-set-93111.html) from Harbor Freight would, without doubt, do the job.

I recently rebuilt my NG3. It's really not as daunting as you might expect. Give the usual suspects a shot at having the parts you need but if you can't find them in the States, Renault 16 Shop (https://www.renault16shop.com/?Lng=en) is your friend.

edit: actually I think it’s a 5/32” punch.

[My S1]

That's exactly what I need....extra length on the punch to reduce the strain on my back!  Any idea what this "special thread cleaning tool" might be?  Simply a brass brass ?

[jbcollier]

It is not a seal retaining nut.  It is a differential bearing adjusting nut with a seal in it.  The diff bearing adjustment is absolutely critical.

Is it possible to change the seal and keep the proper diff bearing adjustment?  Yes.  BUT, I have lost count of the number of people who have screwed it up.  If you are an experienced mechanic then you can try.  I’m a retired 35 year mechanic.  Personally, I would take the transaxle out and do it properly.

First drive the car.  Is the diff quiet?  Any whining on or off throttle in fourth?  If it is not quiet, then take the transaxle out as your diff needs adjusting regardless.  Next pull the half shaft out of the way.  Clean around the seal nut thoroughly.  Mark the seal nut’s EXACT position.  Carefully undo the nut while counting the number of turns until it is free.  Replace the seal (and the o-ring behind the seal run).  Refit the nut to the EXACT same number of turns and final position.  Refit the seal run and use a piece of pipe to pop it fully home.

When everything is back together, drive the car again.  Diff quiet?  Excellent.  Diff noisy, or noisier than it was?  You $&@ up.  Pull the transaxle and do it properly.

Square sealing ring or round?  Doesn’t matter.  I have one of each and both are dry.

The Lotus implementation of the Renault transaxle uses a bit of a mickey mouse fitting of the half-shafts.  While Renaults seldom have oil leaks there, it is very common for the Europa to be at least weeping.  Check and top up the oil level.  Drive it and check it every week until you get a good idea of how much it is leaking.  Less than half a litre a year?  I’d just live with it until the transaxle comes out for some other reason.

Regardless, before every major trip, check the oil level.  The number 1 killer of 5th gear is a low oil level as that is the first gear torun dry.

YMMV

[My S1]

John,  once again  you have scared the hell out of me. 

The transaxle feels and sounds wonderful especially after refilling with the Redline MT-90.  Only problem that I can detect (other than the drip) is that the 3rd gear synchros are definitely heading south.

I will do as you say and monitor the leak closely and keep it topped up.  It had a very slow leak since I got it in '23 with the black, thick old oil.  I timidly assumed it was just the fill nut and put a pan under it but after those 2-1/2 years I only got about a couple of oz of leakage.  After changing out the fluid I now have a considerable drip, though I just noticed this morning that it slowed substantially.

You say so casually;  "Next pull the half shaft out of the way."  What exactly is the proper cadence for removing the whole corner, trailing arm and all?  I think I'll restore the whole suspension next.  Are there any disastrous screw ups that I should avoid? Will all the members drop and crack the hell out of the paper thin belly pan that I so carefully restored?

Many Thanks.

[Fotog]

I've found that if you take the roll pin out at the inboard end of the half shaft and jack up the car so the suspension is hanging, you should be able to pop the half shaft off the transaxle output shaft by simply giving a yank outboard on the top of the tire.  The fact that the trailing arm is mounted with a rubber mounting means that it can be pushed outboard. Hard to describe, but give it a go and the thing ought to pop right off.

[My S1]

Fotog, that is the best news I've heard since the previous owner agreed to sell me the car!  I'll try that before I tear apart the whole rear corner.  I'll have the lower link and the coilover off as well.  I was a bit nervous about removing/replacing that trailing arm by myself with the engine/transaxle installed.

[dakazman]

 I second that procedure, fotog is right on , that’s how I did mine.
I never did get my roll pins in but I use a machine screw to hold it in place. I just can’t get the roll pin started .
Dakazman

[jbcollier]

Been a while but I think I also disconnected the shock from the chassis.  Don’t remember it being anything but straight forward.

[Triton]

I have replaced oil seals and o rings on both side's a few times now trying to get them oil tight.  I polished the part that the seal runs on to make sure there was no wear line. I also put flexible sealant on the splines,.  I still have a very slight leak,more of a stain really. i can accept that,  I just give both sides a blast with brake cleaner every few weeks and check level....