Skip

...a broken ring & pinion!

That's right... the ONLY part on my car that has never been opened or otherwise molested is now a very large paperweight. <img src="graemlins/crying.gif" border="0" alt="[crying]" />

Just into second gear, first AX run of the day, tires just catching traction, and BAM! Felt like a broken axle at first, with all the racket and lurching... that would've been nice by comparison, eh. <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" />

So, anyone out there in the PacNW with a good used tranny? I need something to get back on the road for scheduled events while removing the shrapnel from mine. Ah well, I needed LSD anyway. <img src="graemlins/oops.gif" border="0" alt="[oops]" />

Be careful out there... the only consolation was the amount of folks that have already BTDT, and knew the sound from 100's of feet away.

944 R&P = tick, tick, tick... BOOM!

Skip

Bob S. 1984 Silver

Sorry to hear it, Skip

Isn't the scuttlebutt that the tranny is capable of 300+ Hp? What are you running?

Bob S.

sb944

That's bad news.

Scary stuff for the rest of us too.

Sam.

Skip

The longevity of transmissions (and diffs and r&p's) is more to do with the way they are used... mine had been abused by me for the past 5 years. It had developed some noticable *slack*, and the 1st/2nd gear syncro/slider was hanging on by a thread. I'm not surprised at all that it went... I was launching pretty hard out of a side-raked gate... wheels were spinning pretty hard on the second gear shift... I surely could have been a bit more graceful, but hey... it's a race.

There are Turbos out there with 500+HP and standards tranny's... they either won't last long, or aren't driven hard. My car has comparatively little torque (~186 ftlbs), but I was using some pretty sticky Kumhos.

Ring & Pinion failures in heavily autocrossed cars (especially Pro-Solo) are relatively common... maybe as much so as the #2 rod bearing failure is on track cars. But I've had both now on autocross... guess I'm blessed... or whatever

So, Rennlisters, since I haven't tempted fate by researching which R&P's are best, anyone know if there's a specifically *mo'betta* one?

Skip

Skip

Anyone out there ever cracked open the case to replace this bugger (R&P)? Any tips? Any special tools (or not so special)? Manuals cover it *vaguely*... and I've never seen much said about it.

Does this mean "I'll" be writing the tech article

TIA!

Skip

Dave

BTDT X3, breakin' 'em, not fixin' 'em, 1 a year. I still have the last one (LSD), I've been thinking of opening it up for a look-see if I ever have time. If you write it up, at least I'll have a clue (read, better you than me )

Dave

BTW, my last one went durring a hard 1-2 shift too, but it was more of a "click,click, bam, screech(from the rear locking up)" kind of noise. My first and second units went at low speed, and made the sound you described.

Tom Pultz

[quote]Originally posted by Skip:
<strong>Anyone out there ever cracked open the case to replace this bugger (R&P)?</strong><hr></blockquote>My guess is the whole trans is toast now. That's how Terry's was in his S2. Metal particles were everywhere.

Except for the bad gearing for a NA car, the 951S trans would be good because it's stronger and has a stronger 8:27 R&P ratio.

TaboII

When I blew mine it looked like a grenade had gone off inside. Had to replace the whole thing. Even the outer casing was cracked. really shinny mettle bit inside after something like that happens though. Mayby some one would be interested in a couple hundred pond paper weight.

Anyone, Anyone,?

Scott at Team Harco

Skip - It's really nice to be able to offer some assistance to a master. I did basically the same thing about a year ago. Bought my 85.5 for a song, knowing full well I would need to do a lot of work to get it reliable. After all the suspension, brakes, timing belt, water pump and steering rack work - I thought it was ready for a brisk test drive (2 miles to the car wash). Took the first left off my main road and got on the gas...

...lots of noise, lots of grinding and almost no-go. Walked home, hooked the trailer to the tow vehicle and proceeded to bring poor "Herbie" home for more love and affection.

A short period of diagnosis revealed the problem was internal. Pulled the transaxle the next day and pulled the side cover. There were little bitty pieces of 6 pinion teeth working their way through the box <img src="graemlins/c.gif" border="0" alt="[ouch]" />

This was not a big surprise. When I drained the old fluid out, during the early "restoration" process, I only got about a pint (and it wasn't Guiness) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> The refill with Modil 1 sythetic did nothing to save what was clearly a box on the way out.

Now to the issue you have: How to rebuild.
Get the section of the Workshop Manual (30 - 39) that describes the rebuild process. I'm sure you probably own, or have easy access to it (I photocopied the sections from my local, friendly German repair shop (Munk's - free plug )) <img src="graemlins/r.gif" border="0" alt="[king]" />

Scott at Team Harco

Sorry about that - I hit the "enter" key at an inappropriate time.

Back to the story...

Use the Manual and follow it to the letter. (Except for the fancy dial indicator tool). I was fortunate that all gears and synchros were in decent shape and did not need replacement. However, even if they did, the work would have been essentially the same (just more expensive). Be sure to measure all gaps and use the appropriate snap rings to obtain the minimum gaps called for in the manual. Obviously you will need a press and various pullers and press tools. It is also wise to heat parts as called for. The work is very straightforward and clearly described in the manual.

When the time comes to set the pre-load and gear lash take your time. Spacers of various thickness must be placed under the bearing races to properly position the ring and pinion with respect to each other (as if this were news) <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />

I was fortunate that my local dealer did not pay particular attention to the number of spacers delivered in each packet (that had to be ordered from Germany). I ordered several different sizes and hoped to luck-out by guessing close and minimize the number of times I would have to return to order more spacers. One useful tip is to remove the spacers from the cover side and place 3 or 4 pieces of 1/8" solder between the race and cover. After installing everything, torquing down the bolts, rotating the assembly then disassembling the unit - you must measure the thickness of the crushed solder. This will provide a starting point when determining how much spacer thickness will be needed to set the proper preload on the bearings.

At the same time you must also look for the mesh of the ring and pinion gears. I used liberal applications of zinc oxide (available at the pharmacy).

It can take a lot of trial and error to arrive at the correct gear mesh and bearing preload. Luckily I had the aide of an experienced hand for this. My old pal Lee Kesh - at the Lawrence Technological University - helped me out and gave me the confidence to trust my senses when feeling the amount of resistance in motion and reading the "footprints" in the zinc oxide.

This can be a very rewarding experience to rebuild your own transaxle (I have done several - though this is my first Porsche rebuild). Based on what I have seen of your comments - I know you can and will do it.

If you have more specific questions, please feel free to ask. I don't frequent the list as often as I would like - so you may wish to contact me off list if you do have a pressing question. (scott@teamharco.com should work)

Oh- make sure you get a matched ring & pinion set. I'm sure you have access. I got mine at Vertex (sorry).

Best of luck
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Scott
<a href="http://www.teamharco.com" target="_blank">www.teamharco.com</a>
Team Harco Motorsports
"Win on Sunday, Sleep on Monday"

Larry Parker

MICHIGAN! munks! what? other michiganders
cool... Hay scott i went to your site and noticed a few names like brian scott and kleckner....
you may know my boss evan moen? Is that brians old car?....

skip, did you find the problem in your gearbox yet? When you do my buddy has a 86 951 box with a bad second, maybe you could get some parts cheap?

Scott at Team Harco

I know we're off topic on this now - but yes I do know Evan. And no that is not Brian's old car. It is a car that I prepared. There are no photos there yet - but there is a complete page on building a car for performance rally competition. I use "Talon 2" as the subject.

So what do you do at Morris? And what do you do with your Porsche? And who is this Luke kid that is always dreaming of Morrisdampers?

Just curious,
Scott
<a href="http://www.teamharco.com" target="_blank">www.teamharco.com</a>
Team Harco Motorsports
"Win on Sunday, Sleep on Monday"

*Rothmans*

Skip, Charles Coker has what seems to be a whole bunch of brand new S/LSD trans for sale on eBay.
Try him at
Cwcssc@aol.com
His business is 356 Inc.
I am not techy enough to know if the gear ratios
are what you need or want, but the trans sells
for what just the LSD is worth from what I have
seen. Plus he seems like an all around nice guy.
And by the way thanks for the strut tower mounts and stuff. A bargain at twice the price!
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Mongo

dude skip you just repeated my history...the same thing happened to me....I hate Audi-made transmissions.. <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" /> They break too easy! Was yours a 951 tranny? If you want factory gearing still wouldn't a later model tranny be better? I've heard that any transmissions over 87 for 944s tend to be more durable....but then again thas what i've heard and these people don't autocross

Sorry to hear about the dilemna Skip