Ok, who's the resident "gearbox god"

[Leland Pate]

Well, I was peacefully planning on sending my gearbox to a shop for a rebuild until Superman *had* to ask me why I'm not doing it myself. The that got me thinking, "Hey why am I not doing it myself?"
The first answer of course is that I know nothing about transmissions. But on the other hand, I didn't know much about 911 engine last year.
What is the concensius? You don't hear too much about people doing their own gearbox rebuilds. It seems like I remember seeing something about the job requiring special jigs and such.

Has anyone had first hand experience with this?
Ideas?
Warnings?
Suggestions?

Someone educate me!


gearbox info. 915 out of a '79 SC
220K on it.
1st and 2nd are worn badly, but not critical.

[ChrisL]

Leland,

For what it's worth, I rebuilt the 5-speed transmission on a TR-7 years ago (hey - it was a convertible) and it was one of the easier jobs I've ever attempted. Finding parts after British Leyland went belly up in the US was the hard part. After looking at the parts available for the 915, I don't think you'll have that problem. You may need a few special tools, but after seeing what you've alreay accomplished and the shop facilities you have at your disposal, I think it's well within your capabilities.

Chris.

[Rot 911]

Chris, my first tranny rebuild was also a TR7! Not sure how complicated a 915 tranny would be, but Leland, if it was me, I would first look over the procedure in the Bentley manual and see if it takes any special tools that are outrageously expensive. If not, I would probably give it a try. Seeings how you are out in the wastelands right now with out your Bentley Bible, I will check things out for you!

[Superman]

Yes, special tools are needed to get the synchro teeth off the gear sets. Hoever, I think I know where you can borrow those tools VERY inexpensively, as long as you don't schedule the job at the wrong time.

I do not profess to be any kind of Porsche expert or tranny expert or anything of the kind! But trannies are really not that hard. two shafts with gear assemblies tuck on them, and some shims. The job would take me many hours probably, but John Walker could probably rebuid one in an hour if he focused. I'm guessing really but I bet he could set your tranny on the bench, then hand it to you rebuilt in one hour. Perhaps I'm dreaming.

[911nut]

While I've never had the opportunity to rebuild a transmission, I do have a Bentley manual. I've looked over the transmission section and it looks like you don't have to be a magical elf from the Black Forest to do it. I say give it a shot.

[Doug Zielke]

Lee,
Looking through the Bentley SC manual, and then comparing it with my Factory manual...no contest! I'd say I would have to copy out the Factory manual transmission section for you. Not enough detail in the Bentley, IMO.

As far as you being able to do it... you're probably more capable than most of us amateurs.
Go for it!

[Bill Douglas]

Leland, I think if you can do the engine, you can definitly do the gearbox. All I know is don't cut any corners with trying to save costs. And inspect every component that's going to go back in with a magnifying glass.

No one seems to replace the brake band and excellerator blocks - I could be wrong but I think these "spin up" or "spin down" the gear before it meets with the syncro on the next. If these were replaced with new ones it may give the the syncros a chance of working beter. Warren may know what these do.

[Early_S_Man]

Lee, sure ,you can do it!

Did you get my email?