rowilson

Hey guys I was wondering if there has been any crankshaft thrust bearing wear problems on trucks that are running heavily modified automatic transmissions? I know in other engines where transmissions that are running higher pressures that is required to keep the torque convertor clutches engaged have been rumored to have caused premature engine thrust bearing problems. I don't know if Cummins has done anything to preclude this from happening in the B series engines or not. Am I worrying about something that doesn't exist?

PourinDiesel

I take it your engine is modded?

rowilson

Very mild but enough to slip the anemic stock tranny. I am just looking to see if there is a problem lurking for me if I go and have killer tranny built or not. I just can't see how the pressures put through the convertor aren't detrimental to the crank when it exceeds the stock levels.

AlpineRAM

I've run about 200 000 kms with a bombed engine and a DTT tranny before I had to rebuild my engine. (other reasons)
The thrust bearing was in extremely good condition- no traces of any abuse or abnormal wear.
The effective surface for the pressure applied in lockup that pushes the TC forward is only the area between the input shaft and the reaction shaft, so I don't see too much of a problem there. What's very important is to have the correct endplay adjusted so that the TC won't stick out too far. Another potential issue would be a TC that's out of round or bent and improperly balanced.

HTH

AlpineRAM