T56 with LS7 clutch?

[GeoffP]

I'll just plan to pre-assemble my engine to the trans so I can check everything prior to putting it in the car. Sounds like it'll be time well spent!

[LAMBSKIN71]

Still waiting on Machine shop to cut the spacer, went back and re measured, looks like .450 is going to be the magic number, for my set up at least. I am still concerned about the three raised fingers on the LS7 pressure plate, not sure how that is going to affect things, I was told to meassure to the rest of the fingers that are about 1/16" lower than the three,

[samckitt]

I'm somewhat curious about this too. I have an LS2 from a Trailblazer SS, and am putting a T56 magnum behind it with LS7 clutch. I bought the bigger/outer bearing for the crank thinking it was more durable because it's bigger. Am I going to have to change it & go with the smaller/inner one? What throw out bearing do I need?

Thakns,
Scot

[LAMBSKIN71]

Being that you are using a "truck" motor too, I would assume you would have the same issue as I did, I just went to the local GM dealer and went to the parts dept and told them what i had, they gave me the smaller bering that sits further in the back of the crank, using the larger bering would have caused there to be about a one inch gap between the back of the block and the face of the bell housing. You may need to use a spacer and longer dowell pins like i did, and then ANOTHER spacer for the throw out berring. Then again the issues Ive had may be unique to me because Im using a newer 2007 6.2ltr Escalade bottom end and an older T56, the newer cranks may just be different than the earlier LS based motors.

[LAMBSKIN71]

Oh and Im using the stock T56 throw out berring and hydraulic slave.

[GeoffP]

I really looked my setup over really close this past weekend. I think I'm going to be fine with the smaller roller bearing without needing any spacers. The larger bearing is definitely not going to work without spacers. Everything appears that it will work. I hope to test fit the engine and transmission together in a couple weeks and will share my experience here if I don't forget.

[andrewb70]

There is no need for any spacer, anywhere. The L92 crank is no different than the older LS1 crank in terms of the way that the pilot bearings are positioned. Keep in mind that there isn't a manual transmission option that was ever offered in a SUV.

There are two styles of pilot bearing, the f-body style, which sits deep inside the crank and has a relatively small OD, and the LS7 (maybe Corvette in general) style pilot, which sits further back on the crank (where the torque converter used to be) and has a much larger OD.

If you are using a F-body T56 with a stock bellhousing, then all you need is the f-body style pilot bearing and a stock slave assembly, which will work with the LS7 style clutch.

Also keep in mind that using spacers between the transmission and the bellhousing is not recommended, unless it is machined perfectly and has alignment dowels incorporated in the design. Not having the dowels can potentially throw off the input shaft to crank alignment which will cause poor shifting, increased wear, and clutch release problems.

Andrew

[LAMBSKIN71]

Andrew, thanks for your help. Couple of questions though. I did use the F body pilot berring but, when I went to mate the transmission to the block the trans shaft bottomed out before the bellhousing even touched the engine block. What would cause this? Also the spacer I used was machined for this trans and bellhousing with the holes for the dowell pins and even came with longer dowell pins.
Second question, does the stock F body slave and berring engage the LS7 pressure plate and clutch in the same way as it does the stock F body pressure plate and clutch? I mean i know it engages the same way, I guess what my concern is the three fingers that are higher than the rest of the fingers of the pressure plate, is this something I should be concerned with?