T56 Input shaft bearing question

danbo313 · 10-19-2009, 09:43 PM

Are the bearing races supposed to spin on the input shaft bearing? Here are some pics of the the race and shim.

I'm trying to find the source of the whine I had in neutral/gear.

85MikeTPI · 10-19-2009, 09:55 PM

No. The trans was built with too much preload on the bearing, or you're getting some pressure on the drivetrain. Is your driveshaft a little too long and binding into the tailhousing?

LS1powerhouse02 · 10-19-2009, 10:16 PM

what kind of noise was your trans making?

danbo313 · 10-20-2009, 12:00 AM

I don't think the driveshaft was too long, i could slide it forward some to remove it. I didn't check the endplay on the input shaft before taking it apart..

It was making a whining/wurring noise with the clutch out in neutral. When pressing in the clutch in neutral, it would slow down to a stop. I could also sort of hear it with the clutch in and the car off coasting up the driveway.

How difficult should it be to remove the races? I just pulled this one out with my fingers. The race for the intermediate shaft could be spun by hand, but doesn't look like it was spinning as much as the one for the input shaft. I pulled that one out with some picks. The t56 manual doesn't say much about installing the races.

cody161 · 10-20-2009, 12:31 AM

i pulled mine out with very little effort when i rebuilt mine, i put all new bearings back in and they went back in the same way. mine has no issues to speak of right now.

LS1powerhouse02 · 10-20-2009, 09:03 AM

that is the EXACT same noise mine is making......it is driving me insane.

Keep us updated on what you do and if it fixes it.

Also I know the noise is annoying but is it really screwing up anything? I mean is it something that should be taken care of now or can it wait a while?

Gen414 · 10-20-2009, 09:37 AM

Quote:

Originally Posted by LS1powerhouse02

Also I know the noise is annoying but is it really screwing up anything? I mean is it something that should be taken care of now or can it wait a while?

Well, IF it is a bearing issue, waiting can do more harm, yes. Bearing starts to eat itself up, it will contaminate the fluid, and that fluid gets circulated through the tranny, and once bad enough, can damage other parts. Also, once the bearing starts to go, clearance's start to open up, causing "slop" or "play" in teh tranny, potentially leading to other damage as well.

Gen414 · 10-20-2009, 09:39 AM

Also, teh races are in the midplate pretty good, and normally if you try and pull them out with yuor hand, they will not come out, unless you pull them out JUST RIGHT. Normally, what I do, is either take the midplate, and flip it over (race down) and tap on midplate, and race falls right out. You can also fish it out with a small pick or whatnot.

But, with your hands, normally they are a little snug for that (to be removed with your hand). Not saying it can't be done, but you have to have pretty good hands....

danbo313 · 10-20-2009, 10:13 AM

Well you can see my hand in the pic, and its pretty awesome! I could spin the race pretty freely

Mine was making this noise for a while. I though i might have damaged the bearing/race by putting too much weight on it when I was putting the tranny back in after changing the slave.

I was also noticing some slop in the drivetrain, If was was just cruising along at a normal speed around town and shifted fast and dumped the clutch out it would sound make a clunk like there was some slop.

The input bearing doesn't look bad. I don't see any damage to it or much wear. I will take some pics of it when I go home at lunch.

Oh one other thing, I know the tranny was rebuilt about 4k miles before i bought it and i put about 46k on it in the 2 years i've had it.

LS1powerhouse02 · 10-20-2009, 10:24 AM

Quote:

Originally Posted by danbo313

Well you can see my hand in the pic, and its pretty awesome! I could spin the race pretty freely

Mine was making this noise for a while. I though i might have damaged the bearing/race by putting too much weight on it when I was putting the tranny back in after changing the slave.

I was also noticing some slop in the drivetrain, If was was just cruising along at a normal speed around town and shifted fast and dumped the clutch out it would sound make a clunk like there was some slop.

The input bearing doesn't look bad. I don't see any damage to it or much wear. I will take some pics of it when I go home at lunch.

Oh one other thing, I know the tranny was rebuilt about 4k miles before i bought it and i put about 46k on it in the 2 years i've had it.

I have the exact same slop in the drivetrain myself. Nice to know what it is. Did you have to disassemble the entire trans to get to the input shaft bearing/race?

danbo313 · 10-20-2009, 11:11 AM

So far i just have the Mid plate off. I think I'm going to go get a gear puller and cut a hole in my work bench tonight. I'm hoping my dial indicator gets here soon so i can start checking some end play.

danbo313 · 10-20-2009, 02:43 PM

Alright, here are some pics of the bearings.

and a video!

I appreciate all the input!

the_merv · 10-20-2009, 11:16 PM

When you took the Tranny out could the Input Shaft move side to side and turn easily..or was it hard to spin?

danbo313 · 10-20-2009, 11:37 PM

I don't recall a lot of side to side movement. It wasn't too hard to spin by hand.

danbo313 · 10-21-2009, 01:26 AM

Quote:

Originally Posted by 85MikeTPI

No. The trans was built with too much preload on the bearing, or you're getting some pressure on the drive train. Is your driveshaft a little too long and binding into the tailhousing?

Now I've seen conflicting things concerning preload. I've read article like GM-High Tech performance and other peoples write-ups like this one: http://www.noid.org/~lj/T56/T56.htm

They talk about preloading the main-shaft/input shaft. According the the service manual, you shim for end-play not preload. The counter shaft is preloaded.

Excerpt from manual:
"Place tip of dial indicator on end of main-shaft (23).
e. Measure
1. Input shaft/main-shaft end play by moving
input shaft (10) up and down.
2. Select shim (6) to achieve 0.000 to 0.002 in.
(0.00 to 0.05 mm) end play."

I put the mid-plate back on and started disassembling the tranny the proper way. I tried pulling up and down on the main shaft, but there seems to be no play at all. I wonder if it was preloaded..

I forgot to add this video of the race:

Oh and is it normal for the main-shaft to look like this where the 5th/6th driven gears go? I could pull this gear off by hand.

85MikeTPI · 10-21-2009, 08:24 AM

The small mainshaft bearing looks bad, the input shaft bearing looks scored.. I'd replace both. The mainshaft 5/6 splines appear to be starting to shear. The 5/6 driven cluster will shear on the splines under load eventually. If you plan on keeping the trans for a while, you should look into a new mainshaft and 5/6 cluster..

Input bearing is suppose to have end-play, but alot of builders will add a slight pre-load to it so it remains tight as the aluminum case expands under temp. Goal is to keep it close to 0.000".

danbo313 · 10-21-2009, 09:36 AM

dang, thats not gonna be cheap.. I was thinking it wasn't supposed to look like that. Here's a pic of the gear

I wasn't quite sure about the bearings, thats for the input.

85MikeTPI · 10-21-2009, 10:23 AM

Ouch.. Yeah.. Definitely don't want to put it back like that..

danbo313 · 10-22-2009, 01:55 AM

Hmm, I'm pretty sure I found another potential source of noise.. The Mainshaft large taper bearing should probably not be spinning on the shaft.. I was able to dismantle most of my mainshaft without a press, well i should say most of my tranny without a press or puller.

cole99trans · 10-22-2009, 02:03 AM

whats the rating on a stock input shaft?