a questions for the gurus'

[Waterhammer]

My '00 xj quit on me on the hwy the other day. Being all out of sorts at the time the best option was to tow it to the dealership and have the problem diagnosed. I thought I blew a rod. Turns out its the rear main seal. After reading several threads, articles, and my manual, this is something I can do myself. My question is this- the dealership swears you need to pull the tranny to replace the seal and wants 1250.00, minimum. I'm inclined to tell them where they can stick it and do it myself, just need the assurance that you don't need to pull the tranny on an '00 auto... (although in a pinch I guess I could). Thanks in advance for keeping me sane y'all.

[5-90]

No reason why you should, it's a two-piece rear main (if it was a one-piece, it would be a must.)

If you're at stock height, you can probably get away with jacking up the front end until the axle is at full droop - that usually works for me. If you have a lift (3" or more, especially) then you can do it flat.

You'll want to get a brass rod to push out the upper half (about 1/8" or 3/16" - the rear main has a metal core with a rubber overlay, so you can push fairly hard.) Have a lightweight hammer handy in case it sticks.

Before you get started, pour a cupful of fresh oil, and put the new rear main in there to soak. That helps it go in a lot easier, and helps make it pliable so it will seal quicker.

You'll get the one-piece oil sump gasket for your application, which can save you trouble. I'd also get a set of Small Block Chevvy valve cover studs (or any other 1/4"-20 x 1" or so stud) and use four of them in the oil sump rails - third hole from each end. That will allow you to get the gasket and pan in place, and then hold it with one hand easily while you reach for the rest of the screws with the other. Small screws are 1/4"-20 x 1/2", large ones are 5/16"-18 x 3/4" Torque to 7 pound-feet/84 pound-inches, and 11 pound-feet/132 pound-inches, respectively. Torque stud nuts (if you use them) to 7 pound-feet as well.

This job can be done inside of a day on a flat floor - an afternoon, if you're switch (and don't stop for beer breaks too often.) If you don't have an FSM, get a Chilton's manual - that also covers the job fairly well. Don't bother with a Haynes - I use those to prop up the odd leg on a workbench I haven't made new legs for yet...

5-90

[Matthew Currie]

Assuming that it's a 4.0, and that they did not change the design between '99 and '00 (as I;'m pretty sure they did not) it's the same two piece seal it has always been since 87. You do not have to pull the tranny. Note, however, that this is not the case for the 2.5, according to the 99 FSM.

[Waterhammer]

Absoutely beautiful. You guys rock. Can't thank you enough for the detailed response. Going to pick up the Jeep now...

[IntrepidXJ]

how does a rear main seal cause your engine to quit on the highway? unless you lose all you oil and screw up the engine further?

[Waterhammer]

how does a rear main seal cause your engine to quit on the highway? unless you lose all you oil and screw up the engine further?

It leaks onto the exhaust and billows out blue smoke. Then the oil pressure dropped so I stopped and saw the leak... Risking further damage I shut it down and called for a tow.