Cloud9...68

Literally the day I put the insurance back on my car after its 2+ year track car conversion project, I started getting the jet engine sound from the rear of the car. I'll confirm by putting the car up on jacks, and "driving" it to confirm the noise is coming from the differential area, but it's definitely giving the symptoms.

Assuming I need to replace the pinion bearing, I want to save as much money as possible in the procedure, as the project has left my finances pretty tapped out. I plan to at least R & R the transaxle myself, but I was wondering if anyone at this site has ever (or know of anyone who has) disassembled their own transaxle. I'd like to break it down as far as reasonable and then take it to someone to do the actual bearing install and set-up, both to save on labor costs, and to cut down on the weight of the unit that I have to lug to the shop. I did a search, and couldn't find any info on the tear-down of the 968 transaxle, so I'm not optimistic, but I would appreciate any leads anyone could provide.

RajDatta

I for one would not recommend doing so. This would make a classic situation where it would be questionable who is responsible in case things don't go right. With things like this, it is best to have a shop doing everything. This way they are 100% responsible and there is no finger pointing in the future. You can remove the transmission yourself, but that would be the farthest I would go. Opening it up would not save you much more $$ but open you up to liability.

Transmissions are not something you want to normally mess with.

Cloud9...68

I hear you. It's just that my life is flashing before my eyes as I rocket through all the psychological levels of coping with the tragedy (denial, anger, depression, a few I'm forgetting, and finally, acceptance) of having a major portion of my budget for the intended use of the car (tracking) I've spent 2+ grueling years of my life preparing for wiped out. Ugh... I feel myself slipping back into depression. Can I request a suicide watch, please...?

PorscheG96

I could be mistaken on this but when I had my pinion bearing rebuilt I believe they said that re-bolting the case is a critical step to setting the correct bearing preload, therefore I think that delivering the entire trans to repair shop is best.

PorscheG96

PS. Did you ever sell your CF hood?

Cloud9...68

PorscheG96,

To answer your second question, you may have me confused with somebody else, because I never had a carbon fiber hood. I bought a used fiberglass hood from someone on 968.net, and, amazingly, the fit is nearly perfect, so I definitely have no intention of selling it. I did sell my stock steel hood to someone, though.

If re-bolting the case is indeed critical to setting the preload, then yes, it would be foolish to try to do any of the transaxle teardown myself. I found a thread on another forum started by a guy who did most of the job himself, only relying on an expert to install the bearing itself and of course set the preload, but he never provided any details of the teardown, other than to say is was actually pretty easy, and that the instructions in the WSM were clear enough to follow. But he didn't provide any details of his teardown, and vanished after his last post on the thread, so I have no way of knowing if his job was successful, or if his transaxle grenaded a week after his rebuild.

I just got off the phone with Sunset Porshce to try to find the availability of the pinion bearing, but since the parts catalog doesn't have a listing for a part by that specific name, it was difficult to determine which part I may need. The part number they found was 999 059 064 00, but it's listed as a pair (I've always heard the pinion bearing referred to in the singular), for $56 apiece, and they're available in the US. Could someone who has been through this please confirm if this is the right part, and if not, could you let me know the number of the correct one? Thanks.

odurandina

Cloud,

when I switch to my V8 transmission, I was planning to clone my unbuilt unit (currently in my car) to have the same parts as the V8 box (lsd + 4 taller gears). it's going to cost, but having two proper transmissions for the LS engine is more fun. so, if you dread doing the rebuild (and you should), maybe we can facilitate a trade, since I was planning the full rebuild anyway (and the pinion bearing is one of the replacement items).

Cloud9...68

Thanks for the offer, but it looks like the parts, if there is nothing else needed besides the pinion bearing(s?), are very cheap - only $56 apiece (didn't realize there are two; need to confirm this). I also found somebody locally who's recommended by a machinist I trust whole-heartedly, so given that the box shifts flawlesly, my current plan, once I've confirmed it really is the pinion bearing and not something else (like a wheel bearing), is to remove the transaxle myself, and take it to this local guy to replace the part, and of course any others he finds that are worn.

RajDatta

It would be unwise not to freshen it and do the syncro's while you are in there.

flwbyu

One thing I learned after the third time on my pinion bearing issue was not to follow the Porsche specs directly. The one thing they did not account for was wear and tear, age, etc.. I agree with Raj, that it is better to let someone else deal with the whole removal and build. This is one thing that requires a certain amount of expertise and knowledge to make sure everything is done correctly.

dougs968

Cloud, sorry to hear about the setback. I'm sure my day is coming, difference is (if I can EVER get any time and money ahead ), like OD I will get a spare transaxle, but rebuild it myself. Not recommended by most here, but somebody needs to do it and impart that knowledge to this forum. Kind of suprised no one has yet. Most every other subject with our cars has been covered. It's not voodoo or rocket science, it's a manual transaxle. A little complicated and some special tools required. Should be a fun and interesting project.

pontifex4

Here's an epic transmission teardown by our upside down friends:

https://rennlist.com/forums/944-turb...age-heavy.html

dougs968

Excellent! Thanks for posting that.

Thom

FWIW I have concluded from going through the FSM multiple times that it's going to be very difficult to adjust bearing preload correctly without that expensive VW special tool kit.

I would say that tearing down a properly-working transaxle to replace pinions and/or syncros and/or the differential is not going to be a big deal as long as bearings, and consequently their preload, are left untouched.

odurandina

the #1 rule when you fix part of a working system and don't fix the whole, is the good parts just help the bad stuff to fail sooner.

a transmission is a lot of equipment to move. and you want to play without having new problems... you shouldn't have one of these boxes apart without having the installer replace all the suspect bearings (not just the pinion bearing... bad bearings also cause added stress to other parts), synchros, (incl. all synchro rings/springs), input/output shaft seals, selector shaft seal/s, case gasket, all O-rings incl. selector shaft cover O-ring, updated 1-2 shift outer collar, and even gearsets (2nd and 3rd get pretty chewed up in a relatively short period).

btw, I have good 3~4 gearsets available if anyone needs....


trustworthy rebuilders who will do the job (including the dreaded pinion bearing) correctly;


Advanced Automotion - Corpus Christi, TX, 817 939-6761

contact: Scott Dewitt, http://www.advancedautomotion.com/


Catellus Engineering; Stow, MA, 617 306-0457

Contact; Kevin Gross kgross@connact.com.


California Motorsports CMS - Lake Havasu, AZ, 928 855-5755

contact: http://www.californiamotorsports.net/contact.htm