so i have an oil leak in my 91 xj 4 liter i was told when i got it that the oil pan gasket was replaced before. i know it is leaking from one of the sides and it is leaking from the rear. my question is how do i know if its just the oil pan gasket or if its also the rear main seal

 

Rear main usually weeps from the rear main down. Oil pan would/could be leaking all around. Tough to say if its one or the other for sure really. If you can do it, its only time and a few bucks. Id do both to be sure. If youve got to pull the oil pan to put on a new gasket, mine as well do the rear main while its off.

 

Sounds like the rear main, if I were you i'd do it myself for $30 and 5 hours
vs. pay some guy for $400
just my opinion
heres a good link:
http://jeepin.com/features/rearmain

 

X2
rear main seals suck to do but youll save at least 4 to 5 hundred bucks or more!

 

the rear main doesnt worry me too much the jeep wont be driven much till im out of college so i have a lot of time to do it