I have had my transmission rebuilt TWICE by a forum sponsor here, HORRIBLE WORK. It has had leaks from every possible place from the case to the input shaft seal, and a BAD 5th gear grind right out of his shop BOTH times.


I havent even put 1000 miles on the rebuilds and I just pulled it out for the 3rd time.

addressing the front input shaft seal leak, I noticed when I would jerk the shaft in one direction or another It had play of atleast .055 or more(estimateing without a dial indicator)

What causes the shaft litterally to have room for you to wobble it arround? Would this be the culprit of BOTH input shaft seals leaking?

what is considered normal shaft play?

 

.050 out at the pilot shaft isn't bad, end-play isn't really a spec since the bellhousing alignment and pilot bushing should negate most. The input shaft seal is usually damaged by the input shaft during install, or from dirt/grit from the case. Can you tell if the seal is leaking around the rubber seal, or out around the seal casing?

Alot of wobble in the input shaft would indicate the shimming wasn't done properly. This is easy enough to check with the trans out, and a dial-gauge.

 

A leak from the input shaft seal is very uncommon . I would start by replacing the pilot bearing in the crank shaft for starters if its not brand new already . After that , I would check the block and bellhousing for alignment issues . Missing or worn dowel pins could be the cause of your problems .

If this is on a vette unit , be sure its not the shift rail seal on top leaking , those can give trouble if not properly installed . Also check the cluster gear plug and make sure its not leaking from there either . Its located under the input shaft .

Other than that , leaks from a rebuilt T56 are pretty uncommon .

 

it is a corvette unit, I see a "little" oil on the shift rail seal, but the MAJORITY of the oil comes from the groove where the input seal sits in, you can litterally see it puddleing up there.

When I rock the shaft i can litterally see the seal move some..

I wonder if I installed a sleeve on the shaft and a fresh seal if this will fix my issues?

 

Do you see fluid coming from around the out side of the seal or from the inside of it where it comes into contact with the gear itself ?

 

it almost loooks like its coming from arround the seal, not FROM the seal to shaft region.

 

I took the front cover off, is it normal for the imput shaft bearing to spin kind of like an egg in some ways?

the other bearing beside it had spun perfectly round. When I set the race back on it it didnt seem to be as bad, but again the other bearing did it none at all.

Can I shim it with the front cover off and achieve the proper shimming?

The input bearing has a .036 shim, and the other bearing has a .025 shim

I was looking at it closely with the cover off obviously it has allot of play all the play is moving down in the 4th gear synchro region. How would shimming keep this from happening?

 

Shimming it reduces in and out but all crowds the bearing a little bit more reducing the side to side action . Most of the time , it will not make the unit leak as long as the pilot bearing is in good shape .

 

for me its a corvette unit so it goes into the torque tube with no pilot bearing setup. Same principal though?

I didnt have any issues in the front 1-4th with the trans other than the leak, So should I leave well enough alone and just replace the seal?

I was playing with the input shaft and I accidently picked it up, I believe it dropped back down where it came out, as that main gear blocked it from being removed, Did I do any harm there before I seal it back up? Is there any special alignent? It seems ok

 

I am not that familiar with the Vette drivetrain . I have built several C5 T56's but never done an installation since we only build them . I would imagine there has to be some sort of support bearing or bushing in the tube to help support the input shaft . If so , I would take a look at it and see if it needs to be replaced . Other than that , change the seal and hope for the best .

 

do you have experience for the sleeves for the shaft? Im going to install one, as for this gives the shaft OD more thickness pushing for a tighter seal

 

I seriously doubt you need to sleeve the inputshaft . I personally have never seen one that needed it done . If the tip of the shaft where the pilot would go is chewed up , that could be a problem . As for the actual surface where the seal rides , never ran across one needing attention .

 

the source thanks for all the help man I really do appreciate it. You see, My transmission before it was rebuilt Never leaked or grinded now its doing both. Im going through and checking over everything and I already see the seal looks somewhat damaged from the install.

The seal was installed FLUSH with the bore it goes into, Is this its correct position? I have a new seal to put in and I also have a matco seal intaller kit that put them in smooth and flat.

 

Yeah it goes all the way in against the case . I build my unit totally different from others so I never have an issue with seals . Most build the units from the front to the back . I building mine with the guts going into the rear case and then sliding the front plate on to it .

 

so the seal needs to be flush with the bearing race bore basically, I was confused by against the case, or does it have to go DEEP back into it, leaving it unflush with the bore it goes into

 

I push it all the way to where it bottoms out in the case myself .

 

after calling the gear box, I discovered that the seal was installed backwards. The seals that were installed were the ones without the lip. Being as I didnt rebuild the transmission my self I wasnt for sure if that was the way it was supposed to be but it didnt look right from the beginning.

The side with the spring was facing the outside of the transmission. when its supposed to face the inside. I think I found my smokeing gun.

Theres going to be a longggggggg post about this sponsor when im done.

 

No **** !!!! Yeah I would say thats the problem . Always , ALWAYS ,ALWAYS install the spring to the side you are trying keep fluids from coming out of . Other wise it does no good as in your case .

 

sorry I think I got a bit OT lol

well sometimes you cant see the forest for the trees

I have been paranoid ever since I got some shoddy work done years ago. I now try and do all my own work.. but at the same time its very dauting and intimidating, to think there might be somethign small im overlooking since I dont do this stuff for a living or daily etc.

If we break something we sure as heck will know it and want to make sure we get it fixed, nothing makes me madder than for someone to break something else while fixing on problem only to try and charge me to fix the other thing they just noticed was broke Or when you come back after finding some other noise ticking or clunking that wasnt there before and they say oh thatll be another charge to fix that... grr