That's a great idea on replacing the oil pump, I'll definitely do that when i have it off. Thanks!

replace the valve cover gasket first

yes X2.....oil pump is always pumping unfiltered oil and does wear.....

well, afternoon 3 on the rear main seal replacement. everything going good until i ran into the upper part of the main seal up in the block. Am I doing something wrong here? Just from reading the posts its like its a piece of cake to take this thing out but I'm having a hell of a time beating it on one end of the seal, all i'm doing is deforming . Has anybody else had problems with this? Suggestions?

I dont have an answer but I am curious to know how this turned out for you? Where you able to get the seal out?

sorry its been so long for a reply, but no, i wasn't able to get the top part of the seal out, so i replaced the bottom part, threw in some gasket sealer, and buttoned it all back up. Of course, it still leaks, almost wish i never did anything to it, and i've called around to area mechanics and they won't touch it. They say when they replace them two weeks later customers call back saying the seal is leaking again. They say it won't hurt anything, just gotta watch oil levels alot closer. So, my XJ marks its territory.

Take it apart again and fix it right. The upper part of the seal can be a PITA but you can get it out if you try. Did you have someone tapping the seal with a punch while you turned the crank? Did you try loosening all the main caps? Why go to all the work you did and then half a@@ it?

Dyes RULE for finding leaks. Dump 2 bottles in the oil spout, run the engine for about 5 minutes, then use a black light to find the leaks. All your leaks will show a fluorescent greenish color. (The dye is fluorescent orange but when it mixes with the oil it turns greenish). I found four leaks yesterday. My leaks are: rear of oil pan, oil filter adapter, rear of valve cover, and oil sending unit (all famous 4.0L leaks).

The dye doesn't impact the utility of any fluid. Can be used in oil, tranny fluid, power steering, etc.

You can get the dye and black light on Amazon.

I just got out of the garage your plan will not work. The pan did not just drop out the dana 30 front end driver side will keep the pan dropping out. I needed to jack up the trans n tcase then the pan hit both the starter and exhaust pipe then needed to be removed. I took out the rear main cap I had to work hard to pull the old seal out. That is because after 140k miles of the constant heat and cool down cycle the seal is harden to the engine metal. I did not use a flat tip screw drive because it could nick the bearing surface causing more damage. I tried wooden dowel that did not work pounding on the dowel only broke the dowel. I took a good look at the old top gasket it is not coming out. Long story short I am pulling the engine to change the seal, hell no. I am going to put in the SBC I was planing use so in it goes. I got all the parts and I will be using the AX15 mated to a dana 20 from a bronco. So take that 4.0L if it leaks in the rear pull the engine and do a proper rebuild or change to a SBC I choice SBC.

Yeah. We'll all start doing that right away. Thanks for the tip.

SBC?

I've got a rear main seal leak as well and am having a shop do it. I think the oil pump was a good idea but what's the SBC deal? I'm confused.

Replaced my rear main on my cherokee couple months ago, had 176k on the odo when I replaced it. Sounds like you got the jist of everything based on everyone's responses here but here are my 2 cents

1. it may seem counterintuitive, but dropping the axle down, then jacking it back up a few inches actually provides more clearance than if it was all the way down, the axle moves forward when it rises... i was able to get my oil pan out without lifting the motor or trans this way (getting it back in... that's another story)

2. there should be a metal rod inside the gasket that you can see from the bottom, this is where you should be hitting the gasket to push it out other side. You probably are already seeing this

Small Block Chevy. He feels if you get a rear main seal leak in a 4.0 Jeep, you should yank it out and put an SBC in.....

Don't you think when someone gotta ask they must be very young clicked on your:https://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/ how long did it take you to gather that information I am impressed. Where I not switching to a SBC (the 406 kind) I would copy / paste keeping them for reference I will still copy and paste if can?

Since 1984 through 1992 when I was Service Manager and Shop Foreman at a Jeep dealer. We had direct access to JeepTech and got some good, most times unpublished, technical tips from them.