My name is Garrett and I just got my XJ a couple days ago. The guy I bought it from gave me the Rear Main Seal saying you will probably need to replace this sometime. For weeks this guy was sitting at my job site and I never saw oil but the second day I leave my XJ in the driveway I see oil! >:| So, I'm just going to replace the rear main and oil pan gasket right now and see what happens. I've read a couple write ups but have a couple questions. Letting the front end sag, so where should I place the jacks, or would it be easier since I have a 2.5" lift if I just parked her on the curb. Also, what kind of soap, dish washing, hand? Ect. How serious is it getting the bolts torqued back to spec? BTW this will be the most wrenching I have ever done in my life.

tourqu spec is important. the last pan gasket i bought was a rubber like material, you dont want to push the rubber out with to much tourqu or it will leak. drive it on a curb would be fine with wheel chucks in the rear tire. or set jack stand under the frame

. Tighten the 1/4 inch bolts to 80 inch lbs. (9 Nm); the 5/16 inch bolts to 11 ft. lbs. (15 Nm); the oil pan drain plug to 30 ft. lbs. (41 Nm).

Ok I'll say it I'd clean and inspect there are a lot of easer things to fix that will make you think tis the rear seal if it's the rear seal then at least you know

Thanks for the advice! I do plan on cleaning it up with a pressure washer.

i would say torqueing the bearing cap would be the most important torque in this process. The others are just for good measure, you get this one wrong and you get all kinds of problems! lol.

Have fun, it is a very messy job!

^^

Everything looks like a RMS leak on a 4.0 because of where the leaking oil runs.
The valve cover gasket and oil filter adapter are pretty big offenders.

Read this before proceeding:



I'd be looking up above first, and VERIFYING the source of the oil leak yourself. Many mechanics, friends, and good old Uncle Bob love to tell you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon just yet.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 8-15-2012

Yeah when I got my oil changed at the shop next to my work, they said I have a real seal leak and quoted me $1100 "because they have to drop the tranny". It drips like a drop a day if that. I'll live with my leaky XJ thanks!

Didn't replace the Seal, Changed the oil, filled the coolant, power steering fluid, oil filter, drain plug, and brake fluid. Power washed the undercarriage, haven't noticed any oil the leak could have been the lose filter or the broken washer on the drain plug that was leaking. Hopefully was, thank for all the advice before I just immediately replaced the rear main. There was quite a lot of oil down there though. I did change to synthetic though Mobil 1 of course, just feel like it will be better in the long run.

Keep us updated. Good job.

https://www.cherokeeforum.com/member...ing-off-trans/

https://www.cherokeeforum.com/member...good-10-hours/

After sitting for about 12 hours this is where I'm at, it's not bad at all.

Watch that oil filter adapter closely. Since mine once leaked, clearly that must be everybody else's problem!

Here's a deal on that for anybody interested> http://www.myjeepxj.com/cherokee-rep...filter-adapter