Engine/Transmission (1998.5 - 2002) Crankshaft thrust wear with built automatic transmissions

[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?

 

[zstroken]

I don't think the pressure has anything to do with it. Now the result of the increased pressure could be more holding power, which will produce a thrust condition, the right hand rule crap. The increased pressure of the torque convertor is contained in the convertor. Maybe I am misunderstanding what you are saying.

 

[jwilliams3]

The condition you mention does not exist.

 

[jelag]

The front pump on the automatic transmission is a slip fit into the torque converter... the same way the transmission on a stick fits through the clutch and into the pilot bearing... . In either case... the input shaft... . should never bottom into the torque converter... or in the manual transmission application... should never bottom into the crankshaft... .



Both designs allow for the flywheel (ringgear) and Clutch (torque Converter) to mount to the engine. . and the transmission is independent... ... . they both intersect with some sort of spline... . which allows for the mistakes made in production... or manufacturing tolerence's is a better way to put it...



Hope this helps...

 

[rowilson]

The problem is as jelag states. The convertor slips onto the input shaft of the transmission and into the front pump. To keep the lock up convertor engaged the pressures are increased and the fluid is pumped through the center of the input shaft into the convertor. This increased pressure pushes against the convertor mounted on the flexplate which in turn pushes against the thrust bearing of the crankshaft. Correct? This is a problem I know with other engines but haven't heard of crank failures with Cummins engines. As for jwilliams3's statement that this condition doesn't exist confuses me. Is this based on speculation or experience with racing or pulling transmissions. I know this is a problem with over the road trucks where the clutch pressing in over time takes out the thrust bearing. Not flaming anyone just interested in learning more.