Mike C.

Does anyone know of a souce for transaxle shims (other than the dealer)? How about bearings, circlips, etc.?

badcoupe

most of the bearings can be gotten aftermarket autozone etc. you just need the numbers off the backside of them, Carquest here is about the best source. As for shims most tool and die shops have shim stock in sheets of varying thickness and can cut you shims, I have a customer that owns a mach. shop and I go down there and get what I need and he then bring it home and cut it out.

Mike C.

Update. All bearings pulled out. Closer inspection reveals noticeable wear, especially on the races (no real surprise at 175K). There are several magnets in there too. All are 'furry' with steel bits but this isn't abnormal. So the idea of re-using the bearings is out of the question. I was able to successfully remove the pinion bearing race with my slide hammer & home made tool. It is a very tight fit though. I don't think it will go back in without heating the housing (similar to the caveat on putting wheel bearing races in aluminum hubs without heating the hubs). Luckily, we do have an industrial oven at work that just barely fits the housing. So the question becomes how to safely move around a 300 F aluminum casting and get the race in before it cools off too much... I guess some oven mits ought to do it. I imagine it would be easier to soak the race in LN2 to shrink it but, no LN2 on hand...

Tom Carson

here is a good reference for what the gear mesh pattern may look like and how to correct:
http://www.fiat-spider.net/servicema...toothcheck.htm

in fact there is a lot of good stuff here...like:
http://www.fiat-spider.net/servicema...f-carriert.htm
too bad we don't have these images for our Audi 016 transaxles

Mike C.

Thanks Tom, I have a few non-Porsche shop manuauls that show similar diagrams. Since we're still talking about hypoid gears, I think these will suffice.

badcoupe

some brake clean wil cool the race a little. Or just stick it in a fridge. I froze my four wheeler crank pin before reassembling it.

Mike C.

Update: Success in heating case to drop in new pinion shaft bearing. It took about 20 minutes for the oven to reach 300 F and then I left it in there for another 1/2 hour. The bearing race dropped into place - no force (other than gravity) needed. Metal temperature, as measured with a hand held digital theremometer, was around 250 F after being out of the oven for 10 seconds or so. I doubt it had gotten all the way up to 300 but apparently 250 is enough if you heat the entire case. I then put it up on the press to hold the race down until heat was transferred. Just for practice, I installed the old ring & pinion and put some prussian blue on the ring gear to look at mesh patterns. I can't say things looked very obvious. Web searching shows other gear marking compounds that might do a better job and I haven't yet tried the Zinc Oxide. Some photos included...

Mike C.

Well I uploaded photos... I'm not sure where they went...

Mike C.

Ah.. the images were too big...

badcoupe

not too bad! looks like the pinion may be a little too deep, you need to shim it away from the ring gear. but isn't that the old gears? Remember you have to look at both the coast and drive pattern.

Mike C.

Badcoupe, yes, it is the old gears and shims (note the pinion gear in the first photo). I don't think I had enough prussian blue on there. I read somewhere that the drive pattern is most critical and it would seem the coast pattern would have to follow. What would it indicate if you had a good drive pattern but a poor coast pattern? It doesn't seem you could adjust anything to help - maybe this identifies a bad gear set....

Mike C.

For those following this thread an update: recieved new ring & pinion and have paritally assembled the pinion shaft. Ring gear is installed on the differential and new race (plus old shim) is installed in transaxle case. I took my first gear mesh readings tonight (see photos). I believe the patterns look good - I still have to check ring gear back lash though. Any opinions on the patterns by those who've been there appreciated.

Bob Ward

The pictures seem to show that the R&P does not need any shims??

You are going thru all this work, would it have been worthwhile to get and LSD while rebuilding???

Mike C.

Bob, the original shim is in there (about 0.023" thick). It seems I'm just lucky that things have stacked up such that I may not need to change the shim thickness. You do have a point about switching over to LSD. I just figured it would be more money than I wanted to spend since the new parts (if available) from Porsche would be very expensive and the alternative would be to find a used LSD tranny with a blown R & P. If you go the 2nd route, then you take the chance that internal damage is more extensive than R & P alone... I suppose if I could buy just a used LSD differential unit, that might be affordable but I doubt people will tear apart a transmission just to sell the diff..

Bob Ward

I just saw a used LSD sold on ebay for around 600 (orginal Porsche unit).
6speed racing has guard LSD's (the best as far as I know) for around $1100.
I just figured if you have to rebuild the trans, it would be easier to put in the LSD then.

I need to rebuild mine too as it is leaking all over the place so I got the gasket kit. the rest of the unit looks OK though.

I have blown up several of these and it seems that the spider gears is what goes and the chunks then cause the rest to blow. Your pictures of the blow R7P looks the same, were the spider gears shot too?