T56 input shaft

[Van B]

I am attempting to install my T56 with my LS2. The trans was from a 2002 Z28. I was able to get the input shaft through the splines of the clutch disc and I thought I was having trouble getting it into the pilot bushing. I had it as far as the throwout bearing touching the pressure plate springs.

When I took the trans back down, it looked like the input shaft had been in the pilot bushing, but I could not push it any further in. What are the chances that: A) the input shaft is too long, or B) I was unable to compress the little spring on the throwout bearing far enough to get everything together?

At the closest point, trans case was about 1 inch from the flywheel housing, too far to get a bolt started.

Anybody have any input as to what my problem is? Thanks in advance for any advice.

[Van B]

Update: Had it almost together last night. The first time I had the clutch disc off center just enough not to let the input shaft go into the pilot bearing. After recentering the clutch, I was able to get the trans and bellhousing to within about 1/4 inch by sliding it in as far as I could and drawing it in with the mounting bolts. At 1/4 inch everything stopped solid.

It seems to me like the input shaft is bottoming out in the pilot bearing. As if the tapered part of the input shaft is all the way through and the splined part is pushing in on the pilot bearing.

Again, does anyone know of any compatibility issues with an LS2 and a LS1 T56?

[andrewb70]

One idea is that when the pilot bearing was installed, it was not pressed in far enough. Another thought is that the pilot bearing is the wrong one for the application. perhaps its time to take it apart and start taking some careful measurements. I would seperate the bellhousing from the tranny and measure the depth of the bellhousing and the length of the input shaft. See if there is something odd there.

What clutch are you using?

Andrew

[Van B]

The pilot bearing was pressed in all the way, but the splined portion of the input shaft was bottoming out on the pilot bearing. I took a lot of measurements this morning and found that the pilot bearing needs to be in about 7/16 " further. That or the input shaft needs to have the same distance machined down so the pilot bearing can go over it. Does that make any sense?

I had thought about spacing the transmission out a little, but that would screw up the throwout bearing operation. I am using a Spec Stage 3 clutch for an LS1 F Body.

I am thinking that the crankshaft depth must be different between an LS1 and LS2.

[Mkelcy]

I am thinking that the crankshaft depth must be different between an LS1 and LS2.

I have no special knowledge, but I strongly doubt Chevy changed the crankshaft depth from the LS1 to the LS2. Why would they create an incompatability between two versions of their LSx engines? You'd have to change the block or the crank, and neither seems likely.

I'd look for other issues. As Andrew suggested, take it apart and measure everything. Either the pilot bushing is not pressed in all the way, the input shaft on the transmision is wrong or the bellhousing is wrong. That's where I'd look.

[andrewb70]

The pilot bearing was pressed in all the way, but the splined portion of the input shaft was bottoming out on the pilot bearing. I took a lot of measurements this morning and found that the pilot bearing needs to be in about 7/16 " further. That or the input shaft needs to have the same distance machined down so the pilot bearing can go over it. Does that make any sense?

Is it possible that the wrong pilot bearing was used? Did you press the bearing in or did Wegner do it? Wegner builds engines for circle track and those guys use reverse mount bellhousings and T10 style transmissions. Perhaps that combination of parts requires a slightly longer pilot and that is what was used? I am guessing here...

I had thought about spacing the transmission out a little, but that would screw up the throwout bearing operation. I am using a Spec Stage 3 clutch for an LS1 F Body.

So then you are using an LS1 style flywheel, correct?

I am thinking that the crankshaft depth must be different between an LS1 and LS2.

I believe the crank depth is the same on LS1 and LS2 engines.

Please keep us posted.

Andrew

[Van B]

All I have to say is duh! To answer your question Andrew, Wegner's put the pilot bearing in, and you know how sometimes you have to walk away and do something else to be able to see what was right in front of you the whole time? I pulled the pilot bearing out yesterday and quit working on it.

All the while it had bothered me that the pilot bearing I got with my clutch & pressure plate was so different than the one that the engine builder put in my crankshaft. See pic below. The one on the right is the one that was in my engine, the one on the left came with my clutch.

Andrew, your last post finally got me thinking about it the right way. I went out, crawled under the car and lo and behold, there is another recess behind where the other pilot bearing was and it just happens to be the same size as the piece that came with the clutch.

Many thanks to all who shared their ideas.

[andrewb70]

Let me know when you are ready for a real racing clutch. Not that 45lb truck clutch....LOL

Andrew

[Van B]

I'm afraid to ask what the price tag is on that work of art.

[andrewb70]

I'm afraid to ask what the price tag is on that work of art.

I am not sure what the final pricing will be, but its going to be in the 3K range. You would really only need a 2 disk. The one in the picture is a 3 disk.

Andrew