redhandstudios

My Jeep started gushing oil out of the rear of the block, and all over the transmission as well as the exhaust today. Lost a quart-ish in the sixty miles it took to get her home. (yes I did stop and add oil. Never went over temp either.) There was no knocking noises or anything like that, I didn't let her run very low during the trip home.

My friend (a mechanic, but more of a chevy 350 kinda guy) said it looks like the rear main oil seal to him. So, my questions to those in the know:
1) How bad is this? Is it something I can do in a couple hours? Do I need to take the engine out to get to the damn thing?

2) If I was to do this myself, do I need any specialty tools or should my "standard" Jeep repair tools work?

3) Would I just be better off taking it to a shop and letting someone else do the headache work?

Thanks!
--Todd--

thelaststarfighter13

A rear main is really easy on the jeep 4.0l

Do you have lift and a torque wrench???

If you don't have lift do you have jack stands?

The hardest part is getting off the oil pan. Then getting the seal back in the right place when you put the pan back on. I can go through it step by step for you if you want. The seal is like 12.95 from autozone. The dealer will charge five or six bills for the whole job and a descent mechanic will probably charge you two or three bills. Oh and depending on the mileage I'd replace the oil pump while your under there. Its kinda insurance for that Oh Shi* that might happen.

If you got a couple of hours and aren't scared of getting in there and taking some stuff apart then I'd go for the DIY approach.

92muddycherokee

I did mine and it wasn't that bad. It probably took hours to get to the oil pan and get it off. Maybe 45min to change the actual seal, then another couple hours to get the damn pan back on and the bagillion bolts that hold it on.
Do a google search or even search this forum for links to web sites that have detailed pages and step by step instructions on how to do it.
I would honestly suggest to set a day aside to do this just in case. Another thing is, be careful when pulling out the top part of the seal that goes up into the block. Try to pull straigh down instead of twisting or bending it back and forth. Mine came close to tearing and if it would have I am not sure how I would have gotten the rest of the seal out.
Be prepared for a mess, even with the oil drained when the entire oil pan is out every part of the crankshaft and internals will drip oil.
Not too complicated but somewhat time consuming. Good luck.

JonnyB

hey guys. i am about to tackle this job tomorrow on my 96' 4.0L While i'm in there should i change the oil pump? If i do how or what process needs to be done to the new one to install it? thanks!

thelaststarfighter13

I replaced the pump. Mine had 200,000 miles on it so I figured what the hell. Just make sure and prime it before you install it so it doesn't suck air for a few seconds before it puts oil where it's supposed to go.

Its insurance. And if you eventually rebuild you can reuse the one you know just has a few miles on it.

JonnyB

yah i figure i'm already replacing my transmission....(missing 2nd gear and shifting rough...176,000 miles on it) and i got it all in pieces...so what the heck right! thnks for the info

cpnwrench

Hey folks,

I did a write-up on mine a day or so ago, and you folks were right, oil will drip everywhere when doing this.

buy a small brass punch tho to ensure you don't scratch the crankshaft when removing the old one.

oh yeah, you will have to take off the oil filter adapter housing if its anything like mine (91 4.0 L) get new gaskets for this!!!!! trust me.

you may or may not have to jack the motor up a little to actually get the pan out of the subframe. I know i had to.

good luck, let us know how it went!

cpnwrench

93gc40

BEFORE tearing into the main seal, make sure that is your leak. Rear Main don't ussually just let go as described.. Check the o-rings in the filter adapter and the oil pressure sending unit first and the valve cover. These other sorces will drain down the back of the block and mimic a rear main. If it is the main, might as well do the oil pump while there. Most people can do this PITA job, just take your time. If your real good or very lucky will take 2-3 hours but plan for all day. Main Seal removal can be a major PITA. its an easy job, just can be frustrating.

redhandstudios

That still involves pulling the oil pan though right?
I have to say, thanks to everyone for the input and advice. It has been a helluva week. On top of the jeep going back into hibernation, My fiance is dealing with a death in her family, one of our friends went in for emergency surgery, and we are being evicted from our RENTAL house because the landlord hasn't paid the mortgage in 10 months...Some days you just want to crawl in a hole.
Knowing that the jeep is fixable by me and for under a couple bills really helped boost my spirits again.
--Todd--
(thank God I didn't sell my back up junker.)

thelaststarfighter13

Thats a real good point. The rear main will most of the time be a slow drip so maybe its something else if its gushing...........

Before you do it just post again I'll go through all the finer points with ya.

a1racer

if you are going to pull the pan or be in that area change it anyway cheap insurance

hoopdaddy6

Yours may be worse off than mine by the sounds of it, but when mine was leaking, I was successfull with the liquid rear main repair stuff from the auto parts store. Worth the money if you ask me.

TWILSN7

I had an oil leak down the back of my engine also. I was afraid it was the rear main seal. After checking, I found out it was my valve cover gasket, the bolts loosened up closest to the fire wall. Like 93gc said, take a look to make sure it's the rear main first before doing all the work.

93gc40

Heres the real sucky part, the main will be the cheapest to fix $20-25, seal and pan gasket. If your can swing it an oil pump is good to do just because your there. Parts to fix the other items, all on on top of the motor, cost more, sender $30, VC Gasket 25, Oil fiter adapter ?

redhandstudios

degreased the block today...seems to be a ton of accumulation around the oil pressure sending thingy and the oil filter adapter. My starter motor had completely vanished under a thick layer of crud. Methinks this may be the partial culprit. Going to clean off the oil pan tonight after the show and see whan the pan gasket looks like. The ***** of it all is...I wont have the spare time to devote to fixing this for almost a month.