HughA44s

I recently had the dreaded ring and pinion failure but the good news is that it was relatively mild and torn some teeth off the pinion with little debris generated. The bad news is the tranny was a M220 so I am looking to rebuild. PORSCHE offers some rebuild kits at reasonable prices (shocking). I know the regular N/A kit will work but the first question is will the S2 ring and pinion be a direct replacement? Also, I will attempt this rebuild myself so is there some source of rebuild info? The rest of the tranny is in great condition and shifts well but I will be replacing the diff carrier and pinion bearings. Any adivce would be appreciated. I have access to presses and other tools so I thinl I will give this a try.

Van

Do you have the factory manuals? Those contain all the info -- backlash, play, wear specs, etc.

zoxx2004

that and grand of specailty tools!

HughA44s

BUMP

Oddjob

Im not aware of a transmission "rebuild" kit, other than the gasket/seal sets. How much $ are you willing to spend on a rebuild? A factory new R/P set will be around $1000. If you replace all the bearings and synchros and seals, it will be over $500 in parts. If you want to refresh the LSD unit (pre Turbo S LSD) it will be another $500 in parts.

Only viable source of info for rebuilding transmissions is the factory service manual.

Mike C.

I've never seen a rebuild kit either. To di it right you will also need access to an oven large enough to hold the main aluminum casting. The pinion bearing race cannot be driven in by force - you must heat the case up to around 300 F so the aluminum expands (more than the steel) and the race can be easily lifted out. If you don't have access to such an oven, forget trying to do it yourself. Here is a thread from my rebuild:
https://rennlist.com/forums/showthre...ission+autopsy

Tabor

What did you do to it?

J Berk

My s2 tranny will likely need similar work...It's being torn down as we speak to determine the extent to which it needs work...mean time I am driving the car with an NA trans....did not want to lose the summer!

If it looks like that much work / $ I may sell it as is and keep my eyes opened for either another S2 box or a 968 6-speed.

HughA44s

Porsche lists a Ring and Pinion repair kit that has the ring, pinion, thrust washer and some other parts.n Will get the parts numbers soon - there at work but call Pelican Parts and ask for a ring and pinion. Mike C. thanks for the link will will examine that later. I took a hard look at the pinion gear and there is evidence of fatigue crack growth for some period of time before the final failure. You can see this by the the difference in the way the metal looks. Basically the fatigue failure areas have a flat dark color where as the final brittle failure is shinny. This is why I am looking for a rebuild rather than a used unit. Basically I don't want to buy someone elses fatigue growth.

Mike C.

You got it Hugh. I even brought one of the pinion teeth into work and had one of our SEM microscpe guys look at it to confirm fatigue. I have more photos from rebuild if you want them. You'll notice some are missing from the link - I had to remove some to free up some photo space for other things on the list.... (I think it's a 1 MB limit for photos here).

HughA44s

Hot darn - the material science classes were worth something. Again, thanks for the link. By the way, my son and I just rebuilt the motor and although there are no internal mods (thats my story and I am sticking to it) it is a VERY strong motor and it actually fractured just leaving a stop-light very easy. Now 1/2 mile previous to that, I was doing a break-in test to 5500 rpm which is when I think it broke but just coasted to a stop-light.