broken cases

[GNeric]

Need a little help in figuring out what can keep breaking TH350 cases across the bellhousing. This guy has had this happen in 3 different cars, 6 different transmissions and they all crack from the passenger side where the bell meets the pan rail across to the driver's side to about 3 inches from the other corner. They have poly motor and trans mounts, subframe connectors (non Buick body). They have also tried rubber mounts all around and still cracks cases. No bolts loosening up.

I am getting ready to build him a TH350 and don't want him to come back for me to swap internals at a later date.

 

[Otto J]

I had one do the same thing yearssss ago,We went an used a JW bolt on bell and never had a problem again,Never did find out why it was happening

 

[GNeric]

I suggested a bolt on bell but the guy grabbed his butt at the idea. I realize the bells on factory castings are pretty thin and not all castings are the same. He is going to be picking up an AOD that I built for him this weekend, I'll see if he's changed his mine.

 

[GANGSTER]

CHECK YOUR U JOINTS, SOMETIMES A STIFF ONE WILL MAKE A DRIVELINE VOBRATION THAT CAN DO THIS.

I AGREE WITH THE ULTRABELL FIX, THATS WHAT I USE

 

[fuzzyGN]

I have also heard of engine-to-trans alignment pins to cause this. Usually the pins get pushed in (or are missing all together) when you store a block on end without a crank in it. The pins could be loose etc. also. Worth a look anyway.

 

[PaCemkr86]

make sure the driveshaft isnt too long, Make sure it has enough
travel

 

[chris718]

dowel pins off usually wipe out the pump.wheel shake and vibrations,drive shafts that arent in line with the crankshaft etc.possible causes

 

[GNeric]

Talked to the guy last night and turns out his buddy was not giving the car any pinion angle. They lined trans, driveshaft, and differential up in a straight line. Making their own crossmember to line it all up. I told him trans and driveshaft have to run at a certain angle set to make the ujoints work correctly.