915 w/lsd- need to rebuild?

mikesarge · 04:41 PM

Well, my engine is almost ready, so I thought this afternoon i'd skip out of work early to tackle the gouged shift shaft seal mating surface I noticed on my transaxle nose cone. I drained the trans, a dowel popped out, see here: (where does this go? EDIT: Yes, it's the reverse pin, I'll put it back "where I found it" behind the switch)

Then, I heard some stuff hit the cardboard under the trans- dog teeth. I found 4 of em, but that doesn't mean there weren't more in the oil or elsewhere.

I can't see much inside the trans, so I'm not sure from where they came. Drain plug didn't look *too* bad, but this car was sold to me by a crook, so who knows what was done to conceal any deeper problems.

I did frequently have trouble shifting into first from a stop before, but I got all new bushings, mounts, and a WEVO shifter which I hoped would address that. Looks like I may now need to go full blown rebuild.

What say ye- what are my options?

Who can competently rebuild this transaxle in the Portland, Oregon area? I'm aware of German Transaxle in Bend, Oregon from my experience with Vanagons, and I'd be happy to take this to them, but I'd also be happy to find someone in town.

QueWhy · 02-11-2020, 04:36 PM

Dang Mike! First the missing head stud and now this. I don’t know enough about the 915 or transmissions in general to offer any specific advice but I’m feeling your pain. My gut says a refresh on the trans is probably in order, especially if you want the most out of that sweet 3.1l you have in the works.

yelcab1 · 02-11-2020, 04:56 PM

It means the dogteeth on your first gear bit the dust. It is at least a first and second gear refresh. Sold by a crook? Now we know why.

That dowel is actually the back up light actuator.

QueWhy · 02-11-2020, 05:15 PM

Quote:

Originally Posted by mikesarge

Who can competently rebuild this transaxle in the Portland, Oregon area? I'm aware of German Transaxle in Bend, Oregon from my experience with Vanagons, and I'd be happy to take this to them, but I'd also be happy to find someone in town.

Maybe try reaching out to Steve Weiner at Rennsport and see who he uses/recommends(maybe they do trans work too). I live in Bend and drive over the hill to Portland fairly regularly, I could probably take the wife’s truck and facilitate one leg of the journey at least.

mikesarge · 02-11-2020, 08:01 PM

Quote:

Originally Posted by QueWhy

Maybe try reaching out to Steve Weiner at Rennsport and see who he uses/recommends(maybe they do trans work too). I live in Bend and drive over the hill to Portland fairly regularly, I could probably take the wife’s truck and facilitate one leg of the journey at least.

That is a very generous offer! I may take you up on that if I can’t find someone in town. I’ll follow up via PM.

For anyone who stumbles into this thread in the future- I found two threads which confirm that I’ll likely need a rebuild, and have a ton more info on this issue and diy rebuilds- “crunchy bits in my transmission” and “gordo’s 915 transmission rebuild”

Matt Monson · 02-12-2020, 03:23 AM

German Transaxle is in Bend. They can do it. Steve used to use Gordon Ledbetter at Orehon Rennsport, but I’ve been told he retired.

Peter Zimmermann · 02-12-2020, 10:36 AM

Mike, for more DIY info check out my 9-part 915 repair Tutorial at Porsche wikidot...

mikesarge · 02-12-2020, 11:10 AM

Quote:

Originally Posted by Peter Zimmermann

Mike, for more DIY info check out my 9-part 915 repair Tutorial at Porsche wikidot...

Hi Peter-

I read through it last night. Very comprehensive, and undoubtedly a huge asset to the DIY community. Thank you for making it available! The R&P portion in particular made me quite nervous as a DIY guy. I'm comfortable with most work on most cars, but the precision required for engine and transmission rebuilds always makes me question my abilities. Doubly so with a trans as expensive as the 915.

I'm considering either 1) buying a used trans in unknown condition, and installing that temporarily while I rebuild mine myself, or 2) having my trans rebuilt and waiting patiently.

It'll depend on whether or not I can find a good used transaxle more quickly than I can figure out how to get a good quality rebuild somewhere close to home.

Trackrash · Trackrash's Garage

Quote:

Originally Posted by mikesarge

Hi Peter-

I read through it last night. Very comprehensive, and undoubtedly a huge asset to the DIY community. Thank you for making it available! The R&P portion in particular made me quite nervous as a DIY guy. I'm comfortable with most work on most cars, but the precision required for engine and transmission rebuilds always makes me question my abilities. Doubly so with a trans as expensive as the 915.

I'm considering either 1) buying a used trans in unknown condition, and installing that temporarily while I rebuild mine myself, or 2) having my trans rebuilt and waiting patiently.

It'll depend on whether or not I can find a good used transaxle more quickly than I can figure out how to get a good quality rebuild somewhere close to home.

Buying a used transmission of this vintage is very risky, unless you have personal experience or history of the trans in question. AHIK

mikesarge · 02-12-2020, 12:19 PM

I agree, which is why it'd be a temporary solution at most.

After talking with several folks about rebuilds, it sounds like a rebuild can be somewhat risky too, so I'm feeling a bit like I could be screwed any way I cut it. At least if I can get a working used unit in the car, I can get back to enjoying the thing while I rebuild the trans on my own, which seems like it could end up being the best option.

darrin · 02-12-2020, 12:41 PM

Mike, I'd follow Matt Monson's advice on German Transmission in Bend. Matt's with (owns?) guard transmissions (google it) and works with/sells his products to a number of companies that work on Porsche transmissions, giving Matt good insight into who to seek out (and who to avoid). I briefly worked with German Transmission to replace a failed transmission in my friend's (Subaru-engined) westy and found their knowledge/customer support/product to be first rate. Can't remember who I talked with at German Transmission, but believe he was the principal/owner there.

Trackrash · Trackrash's Garage

Quote:

Originally Posted by mikesarge

I agree, which is why it'd be a temporary solution at most.

After talking with several folks about rebuilds, it sounds like a rebuild can be somewhat risky too, so I'm feeling a bit like I could be screwed any way I cut it. At least if I can get a working used unit in the car, I can get back to enjoying the thing while I rebuild the trans on my own, which seems like it could end up being the best option.

Agree, that Matt, is the MAN, when it comes to 911 transmissions, so worth checking that out.

There are a couple of good threads on rebuilding these transmissions. I have done it. It does take some specialized tools. You probably won't have to mess with the ring and pinion set-up, unless there is a problem there.

On the positive side, you know that, most likely I am assuming, that none of the gears make noise. So you have a basicly good box and won't have to mess with changing gears.

The next challenge is figuring how far to to go once in there. Will it be a basic refresh, with new synchros and dog teeth on first and second gear? Replace the bearings that need it?

OR go full on and replace every wear item, meaning all bearings and synchros and sliders/ dog teeth?

Then there are some upgrades, like a one piece retainer. Oh I almost forgot, a lot of those cases need to be machined due to loose bearings....

Here is a good read. Gordo's 915 Transmission Rebuild

Jonny042 · Jonny042's Garage

Quote:

Originally Posted by Peter Zimmermann

Mike, for more DIY info check out my 9-part 915 repair Tutorial at Porsche wikidot...

I second that! And also, Peter, thanks for your contribution to the DIY community in posting that!wonderful tutorial!

Gordo's thread is also a great read and was equally useful.

To the OP, I apologize that I don't "know" you well, but if you're comfortable enough building a motor a basic 915 trans refresh isn't really that hard as long as you aren't touching the R&P. The specialized tools required to take apart the mainshaft and pinion/countershaft aren't really that big a deal to aquire.

In fact, it's downright fun.... and you'll get plenty of good advice here.

Whatever route you end up choosing, I'd like to add that there does seem to be a lot of hand-wringing and gnashing of teeth when it comes to synchros and dog teeth and the general quality of available parts. Last spring when I did the Rot Rod trans I used all "OEM" parts, generally the cheapest of the options available on the Pelican site, and had no issues whatsoever with the quality of the parts, and the car shifts like an absolute dream now:

timmy2 · timmy2's Garage

When you go pick up you engine that Al is finishing off, maybe head to Marysville and drop the tranny off with John Walker.... give him a call first to see if he’ll take it on.
His contact info is in this post.
Blew 2 coils in 24 hours

evan9eleven · evan9eleven's Garage

For what itts worth— here is a link to my rebuild adventure. I’d never done a gearbox before but thanks to Peter Z’s tutorial and the great members of this forum the rebuld went fine. I also rebuilt my LSD and set up the R&P myself. The only thing I didn’t do was the machining.

915 rebuild and ITB/EFI project, here we go!