I recently traded my 2010 ram 1500 with 4.7 for an 07 ram 2500 5.9 cummins with 254k miles. Before I could leave the lot the rear main started leaking. They put new seal in but stated that the thrust bearings were weak. They offered to reverse the trade or to give me 1500dollars with the Cummins to go towards repairs. What should I do??

 

Sounds like a sign from above to me...I'd bail out while I could, and find another one to trade for......Ben

 

That's what I have been thinking. I just didnt want to walk away if it was something easy.

 

Thrust bearing on the crankshaft being weak- run Forrest!
This is usually caused by either a crash (massive deceleration, inertia of the crankshaft smashing the bearings) or running without oil pressure... or extremely incompetent installation of a transmission.

The bearing replacement is easy- pull engine, remove head, remove pistons and conrods, pull crankshaft, install new bearings ( rather cheap from Cummins) and reverse the disassembly :-)

But I would bet that you'll find a lot more to do during the teardown..