Getting Ready for 915 Rebuild - It's my turn.

[Christien]

How's the other end of your input shaft? And the pilot bearing in the flywheel? I ask because that was the cause of my shifting problems - the pilot bearing had disintegrated into nothing and the end of the shaft was worn. I was able to have it chromed and ground, rather than replacing it - about $200. See the pics on p. 1 of my rebuild thread:

Christien's 915 rebuild

[arbita1]

Originally Posted by coollx

Matt,

Assuming the area of the shims surrounding where the pinion and input shafts go thru them isn't beat up or curled over, I think you just need to put them aside for now. You'll re-install them upon reassembly assuming you don't change the pinion bearing.

If you do you do a search regarding the loose pinion race you'll find a lot of discussion about it. Depending on how loose it is some solutions are very expensive. My race was a bit loose so I took the approach of using loctite bearing retainer which is supposed to be designed for this kind of problem. Some people think it won't last others think it may. I decided to try it.

As far as the circlips, there's a special tool for removing those that's not too expensive.

Dom

I had originally bought a snap ring pliers and realized they were the wrong thing when I tried to use them. Today I bought a lock ring plier (which looks like the tool shown in the Bentley manual so I think I have the right tool now.)

On this pinion bearing issue. I did some research and am not happy. Yes...my bearing is spun

However, it is not loose to the point that it moves around. I can spin it in its position. And I can remove it. But it slides in and out tightly. So I am HOPING that I am a canidate for the Loctite solution. The Wevo solution is $ 1,000 plus I'm very afraid to mess with the differential.

What are the symptoms of a spun bearing by the way?

[arbita1]

Originally Posted by Christien

How's the other end of your input shaft? And the pilot bearing in the flywheel? I ask because that was the cause of my shifting problems - the pilot bearing had disintegrated into nothing and the end of the shaft was worn. I was able to have it chromed and ground, rather than replacing it - about $200. See the pics on p. 1 of my rebuild thread:

Christien's 915 rebuild

I saw that when I previously read your thread. The input shaft looks good. As for the pilot bearing on the flywheel...I have no idea.

This transmission didn't come off my car. I got it as a core from a fellow Pelican and I'm rebuilding it so I can keep driving my car while I'm doing the work. I haven't dropped the engine yet.

[Christien]

Ah, ok, gotcha - sorry if you mentioned that earlier and I missed it. Smart move, rebuilding a 2nd one so you can keep driving! When you swap it out, remember to have a look. The pilot bearing is cheap - $22 if memory serves. Oh yeah, and replace your RMS! I didn't, but will when I pull the engine/tranny again in a week or 2 for a reseal.

[coollx]

What are the symptoms of a spun bearing by the way?

Matt,

I'm not sure what all the symptoms of a spun bearing race would be, but I think one might be a pattern of movement on the outside of the race and the inside of the bore the race fits into in the housing. I think a normal race has a fairly shiny surface on the outside just like the outside edges of the inside where the roller bearings do not touch. If you see dull or black marks on the outside it might mean its been moving around.

What I did was to measure the o/d of the race and the i/d of the bore and found the difference to be only a few thousands. Plus, the inside surface of the bore where the race fit in was still smooth with no apparent damage. Therefore, I decided to take a chance and use Loctite 648 Retaining Compound which is a high strength/temperature product for retaining close fittings/press fit cylindrical assemblies. I think if the race is not too loose, and can't be wiggled side to side with your fingers, it may work. At least I'm hoping it will.

Dom

[Peter Zimmermann]

Originally Posted by arbita1

The shim depth is .015". There are three shims. What does that tell me? (1)

I can remove the pinion shaft bearing race. What does that mean? (2)

1. Shim depth? The shims were used to final-adjust pinion depth, clean the shims and check them for wear (which is common on transmissions with a loose bearing race). You might have to replace them with new from the P-car dealer. They come in .10mm, .15mm & .20mm - measure them and write down the info. Also, check the bearing surface of the clamping plate carefully. You might have to go with a WEVO because I think that the P/S clamping plate is NLA, if you need a replacement.

2. Loctite sleeve retainer will not work, and peening usually won't either. Remove the diff carrier bearing races from the housing and cover (mark them or replace them!), buy a new bearing for the P/S, pack up the housing, side cover, and the outer bearing race and prep it for shipment. The machine shop that I use (in Los Angeles) will do the reinforcement that I do on all the 915s that I repair - $150. PM me for their address if you want to go this way.

Bear with me, I would send a couple photos, but I'm using a temp PC - my big-bucks Dell laptop took a dump and is being repaired!

Pete

[arbita1]

Originally Posted by coollx

Matt,

I'm not sure what all the symptoms of a spun bearing race would be, but I think one might be a pattern of movement on the outside of the race and the inside of the bore the race fits into in the housing. I think a normal race has a fairly shiny surface on the outside just like the outside edges of the inside where the roller bearings do not touch. If you see dull or black marks on the outside it might mean its been moving around.

I meant really what are the symtoms while driving? Is there a noise, vibration, etc.?

Here are some pictures of what the race and the housing looks like.





There is some visible wear on the outside ring...so it definitely was spinning. However, it fits in the hole tight still. I measured the gap between the race and the housing to be .076mm. So I'm thinking I should be able to use the loctite.

The 660 version is made for spun bearings. It's also supposed to fill gaps up to .020".

Pete...I wrote this before seeing your post. I'm going to PM you for info.

[arbita1]

The brake bands, anchor/stop blocks, and dog teeth I think look fine. Can I just replace the synchro, or do I need to replace the internals as well?

[arbita1]

The brake bands and anchor/stop blocks look okay here too? Do they need to be replaced?

[arbita1]

A bit more wear on the brake band on this gear for some reason.

[dentist90]

Originally Posted by arbita1

I meant really what are the symtoms while driving? Is there a noise, vibration, etc.?

Here are some pictures of what the race and the housing looks like.





There is some visible wear on the outside ring...so it definitely was spinning. However, it fits in the hole tight still. I measured the gap between the race and the housing to be .076mm. So I'm thinking I should be able to use the loctite.

The 660 version is made for spun bearings. It's also supposed to fill gaps up to .020".

Pete...I wrote this before seeing your post. I'm going to PM you for info.

If the race came out of the tranny housing without forcing it it is surely loose (spinning) in it's bore. As long as there isn't much freeplay, bonding it back in is a possibility, although many will argue that is is not ideal. Check the bore carefully for cracking. If any is seen the housing is toast. If you see a crack like this don't use the Loctite bonding approach. Same crack from opposite views:

[Porsche_monkey]

I would definitely try the Loctite, provided, as the good Dentist said, there are no cracks.

[Peter Zimmermann]

Matt: pm sent. Re: 2nd gear - the critical thing is to measure the new synchro in its installed position. You can have wear on the inside of the dog teeth that you really can't see, but that wear will allow the synchro to rest outside the factory acceptable range and cause terrible shifting even with a new slider (which must be replaced with new synchro rings). Order your 1/2 synchro rings and your 1/2 slider. Measure your new 2nd synchro (no groove) after installation, if it's too big then you can order your new dog teeth.

FYI: Anchor blocks, brake bands and energizer blocks are pretty bullet-proof. Usually they are damaged during major synchro failure, if they look good and no trauma has occurred you can normally re-use them. The bearing opening crack in the housing pictured above is wild - and fortunately so rare that I've never seen one like it!

[arbita1]

Originally Posted by Peter Zimmermann

Matt: pm sent. Re: 2nd gear - the critical thing is to measure the new synchro in its installed position. You can have wear on the inside of the dog teeth that you really can't see, but that wear will allow the synchro to rest outside the factory acceptable range and cause terrible shifting even with a new slider (which must be replaced with new synchro rings). Order your 1/2 synchro rings and your 1/2 slider. Measure your new 2nd synchro (no groove) after installation, if it's too big then you can order your new dog teeth.

FYI: Anchor blocks, brake bands and energizer blocks are pretty bullet-proof. Usually they are damaged during major synchro failure, if they look good and no trauma has occurred you can normally re-use them.

I thought 2nd gear dog teeth looked a bit worn so I was planning on replacing it anyway. Do you think otherwise?


With exception of 2nd Gear I think all the brake bands, anchor/stop blocks look good enough to reuse.

In regards to the differential race bearing. Thanks for PMing me the shop info. I responded to you, but I'll post here to for other people to comment.

If I send the differential case to a shop for reinforcment, I have to remove the differential. With all the info on here about preload, backlash, etc...it's kind of scaring me that its not a DIY job. Can anyone comment?

Also, if anyone knows of any shops in the NY/NJ/CT area that may be local to me I'd appreciate it.

[Porsche_monkey]

Originally Posted by Peter Zimmermann

Matt: pm sent. Re: 2nd gear - the critical thing is to measure the new synchro in its installed position. You can have wear on the inside of the dog teeth that you really can't see, but that wear will allow the synchro to rest outside the factory acceptable range and cause terrible shifting even with a new slider (which must be replaced with new synchro rings). Order your 1/2 synchro rings and your 1/2 slider. Measure your new 2nd synchro (no groove) after installation, if it's too big then you can order your new dog teeth.

^^ Read this carefully. It is good advice. I had that synchro issue from worn dog teeth I couldn't even get into fifth. Very annoying to yank it, repair it (again) and re-seal it. Spend a few bucks and do it right.

[coollx]

Matt, if RENNWERKE in Elmsford, NY is reasonably close to you, Cheech the owner and his people are very good and I'm sure they could set the differential up for you.

Dom

[Peter Zimmermann]

Originally Posted by arbita1

I thought 2nd gear dog teeth looked a bit worn so I was planning on replacing it anyway. Do you think otherwise? (1)


If I send the differential case to a shop for reinforcment, I have to remove the differential. With all the info on here about preload, backlash, etc...it's kind of scaring me that its not a DIY job. Can anyone comment?(2)

1. Sorry, Matt, the pictures aren't clear enough to tell...

2. Every diff housing that I've had reinforced I have replaced the diff carrier bearings, and have measured pinion depth, pre-load and backlash. I have never had to alter an original setting. If you put the old carrier bearings back in you might have to re-set pre-load (sometimes they loosen up), but that will not effect pinion depth or backlash. You will not lose any settings by simply R&I the diff...

[arbita1]

Originally Posted by Peter Zimmermann

1. Sorry, Matt, the pictures aren't clear enough to tell...

2. Every diff housing that I've had reinforced I have replaced the diff carrier bearings, and have measured pinion depth, pre-load and backlash. I have never had to alter an original setting. If you put the old carrier bearings back in you might have to re-set pre-load (sometimes they loosen up), but that will not effect pinion depth or backlash. You will not lose any settings by simply R&I the diff...

No problem...I ordered new dog teeth for the 2nd gear anyway.

I spoke to Bill at EMS. He was very nice. They charge $ 300 + shipping to reinforce the race bearing. He said they bore it and insert a new steel sleeve that the new race can be pressed into.

I wish I could find someone local though, so I wouldn't have to pay for all the shipping...seems wastefull. Maybe tomorrow I'll give Gary Fairbanks a call and see what he recommends.

Honestly...I still haven't completely ruled out the loctite solution either.

[Porsche_monkey]

How much play do you have? And (Peter Z) why do you say no to the loctite? Concentricity issues?

[oregonmon]

Ugh, I wish I had the ability to do this.