98 4.0 - which rear main seal to buy?

[ElleShooTiger]

We have a 1998 Ranger 4.0, I'm about to put it into the shop to have the tranmission swapped out, and figure I might as well change the rear main now (its got 250k on it haha). The parts stores, as well as the Fel-Pro catalog, lists 2 seals, one that is PTFE rubber, and the other one comes with a "wear sleeve". I'm guessing the first one is the original style, while the newer one is means for cars with higher miles that might have some wear on the crankshaft?

 

[stx4.0]

Your correct for the most part.They both will use the same actual seal but the wear sleeve is just a thin metal sleeve that fits on the crankshaft where the seal rides to give the seal itself a fresh surface to seal to.Also they say the 4.0s crankshaft was machined so smooth that it was hard for the seal to do its job so those sleeves are supposed to have the correct finish to allow proper sealing.I have been around alot of 4.0s and none ever had problems with leaking at the seal but they say it is a problem?So alot of people add them regardless.I bought a set for the front and back because my crankshaft had pretty good wear but i didnt notice any difference at all in the finish on the crank verses the finish on the sleeves.