captainOCD

Looked like about 50 bucks a piece, but supply seems to be the issue there.

GregBBRD

......I must have a defective set that I'm judging.

I measure all of the shafts I have, except the later automatic shafts, slightly smaller...enough that the bearings slide easily on these shafts.,

(And none of the shafts I have are from the first 54 cars.)

GregBBRD

Yes, Porsche discontinued them, last I checked.

I have them.

islaTurbine

This is a timely thread for me. I’ve got a noisy TT on my ‘78 and have been considering my options between the two suppliers listed here.

Kevin in Atlanta

You are within driving distance of Constantine.

GregBBRD

I actually like 928 International's bearing better than Constantine's....both in terms of cost and in terms of weight. (Thinking that the heavy bearing carrier will take the place of the counterweight is not correct, according to every single "harmonic engineer" I can find.....I love to see Constantines's documentation and harmonic testing that tells him that he is correct.)

On a 1978 car, I'd "add" in the later counterweight to the torque tube, in order to take advantage of Porsche's latest engineering (I have these, brand new and complete with the rubbers, from Porsche.)

Hopefully, I can figure out why Mark and I are getting a discrepancy on dimensions/fit....probably just me....my old brain gets confused, at times. (Although my son discovered the problem while trying to assemble a manual torque tube and brought it to my attention.)

captainOCD

I can say one thing for sure about the vibration dampener, pulling it in and out of the torque tube sucks.

captainOCD

I got the bearing cap off the input shaft tonight. Tried pulling it off first, but it didn't want to budge and all I managed to do was break an ear off. Putting some vice grips on it and using another pair to give a surface to tap on with a hammer got it out though.







Again, noise travels, so it's hard to tell, but with the stethoscope against the outer race, it still doesn't sound like it's the loudest there. That still seems to be from right ahead of the input shaft on the main shaft.

Tomorrow I'm going to get a wooden dowel and it looks like I ought to be able to push that through from the diff side as I pull the countershaft out to catch the gears. Then hopefully the only gear that has to come all the way off is the frontmost one that engages with the input shaft. Looks like I shouldn't have to disturb the selector shafts and forks to pull the input shaft too.




Crossing my fingers that one of the needle bearings in the input shaft is the problem.

GregBBRD

No.

The needle bearing on the input shaft are never bad enough to be noisy. I routinely replace them, as they do get little grooves in them from the cage. And trust me, you wouldn't want those needle bearings to be your problem......those bearings going bad would ruin both 5th gear and the pinion shaft. Huge dollars!

Same with the needle bearing on the layshaft....ruins the layshaft, which is a matched set with 1st and 2nd gears. Huge dollars!

You want to hope/pray that the ball bearing for 5th gear is your problem!

captainOCD

Then hopefully it's just the ball bearing. (Insert joke about rollercoaster of emotions)

belgiumbarry

Hope for you too !

PS Matt, i admire your courage.... i am "hobby wrenching" for 44 years now on rally cars … even partly engines …. but never touched a gearbox. That, i always leave to a prof for rebuild.
Always a inspection/rebuild in the first place and never had problems with them….

For my rally 928 build now i have a "inspected" LSD '88 transaxle ( OK, now 10 years on the "shelf" ) and a spare one from a '90 GT , good condition , as i drove that car … also 10 years ago. That one i would swap the way it is. I even have bought at the time the better LSD from Carl to swap in the '88 box but didn't daire to do it myself. It's on the shelf for a prof to do

captainOCD

I don't think I'd want to tackle a whole rebuild (don't have the tools or experience to do that), but it seems like this bearing shouldn't be too bad of a job and shouldn't involve anything that requires adjustment, shimming, etc.

GregBBRD

Different people have different levels of ability.

I've never removed the 5th gear bearing (input shaft) without having the entire transmission apart, as by the time that bearing goes bad (and puts all of its metal into the transmission), the layshaft bearings are also suffering (from age and the loose metal from the 5th gear bearing). The other issue, by the time the bearing goes bad, is that the synchros are generally at the end of their life expectancy....especially in the lower gears.

Regardless it is technically possible, although it will be a bugger to get out of the case.

By the time you are done, you will need almost a complete gasket set. I have these, with a Viton input shaft seal (new product) that is much better than the original $40 seal, for a great price.

I have 5th gear bearings at a price no one can touch, and the NLA needle beatings for 5th gear and the layshaft.

captainOCD

I don't have the wsm in front of me since I'm not at home, but if I pull the diff apart to pull the main gearset out of the transmission, am I going to have to worry about resetting tolerances up or anything that requires special tools? If not I could pull the mainshaft out from the diff side.

I guess this is where the history of this transmission being unknown isn't helping much. To my inexperienced eye, it looks like this transmission has been been rebuilt before. There some paint marks on bolts that don't appear factory as well as some etchings on gears, both in the trans and on the ring gear on the diff (can see those on the one photo from last night). If it was in fact rebuilt I don't know how much was touched and how much wasn't. I suppose in an ideal world, the syncros and needle bearings were replaced and this input/5th gear bearing was left alone due to cost, or maybe it just got stuff built up in it sitting (it's branded *** with part number 562306 if that tells anything)? I'll be sure to take a look at the syncro that looks like it will come out with the input shaft and post up some pictures of that. The trans shifted butter smooth for the week I had it in.

This car was always intended to be an ongoing project for me and to learn about new things outside of the old mopar and chevy world I grew up in. I've never worked on a manual trans before (have rebuilt several turbo 350s with my dad and grandpap), but I don't mind learning about it. That said if there's some stuff that I just flat out can't do without expensive specialized equipment, I don't want to bugger it up beyond where someone else with the equipment could fix it.

GregBBRD

If you can rebuild a turbo 350, this should be a walk in the park.