jj1562

Does the '96 4.0 have a 1 piece seal or 2? I was told if it's 1 piece, the trans has to come out, if it's 2 piece, do it from the oil pan, any truth to this? I'm hoping this will fix my oil leakage! I thought it was my trans leaking but further investigation, it looks like it's the RMS, bought a trans cooler anyway so I need to install that this week, thanks for any help in advance,

cruiser54

2 piece seal. All of them.

Might wanna read this before jumping on the rear main seal bandwagon:

　
I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.
Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.
Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling 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 and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

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 02-26-2013

jj1562

Thanks for your input cruise: here's my situation back in midsummer it started to leak in that area, I did a few searches and found the topic of the RMS, someone first said to check the tranny fluid level that if it's high it would pour out of the vent tube and to do the proper fluid change, I did 4 "pan" changes and it seemed to help and get rid of most of the black tranny fluid, prior to the first change, it would bang into gear and then all gears shifting, after the fluid change, knock on wood, she shifts perfect and hasn't leaked since, this past weekend I did a lot of driving looking for my honey hole of a fishing spot, then got jammed up in some traffic, stop and go for about an hr, finally made it to the pkwy and she started smoking like a SOB! Pulled over and looked under and saw fluid dripping out from between the block and trans onto the exhaust, the first time this happened there were a few small drips that landed on the exhaust, this time, a hell of a lot more, trans was and still shifting fine, got her home and the drips were relatively small, I'm a mechanic for a bus company here in NY so I asked a few of my partners, 1 worked for Chrysler the other has been working for a trans shop for 10 + years, we looked at the fluid dripping down and compared it To the the eng oil on the dipstick and appears to be the same color, rather than the trans fluid, we checked up top and all around, checked all the bolts on the trans pan and eng oil pan, bought a trans cooler anyway and going to install that tonight, going to bring it to my friends shop to get it on the lift and do a real thorough check, to us it looks like it's the RMS, I'm not by any means denying what info you gave out, just saying we checked pretty much everything and came up with this, thanks again for the help, I'll post the results, hopefully soon!

phobia

It is a 2-piece, and it can be done without removing the trans. You will have to remove the oil pan to access it, but that's a heck of a lot less involved.

cruiser54

Cool. Just making sure. That's why the write-up is written the way it is. You never know someone's mechanical ability or the abilities of their friends and relatives. You'e sure got a handle on it.

jj1562

I hope so! Lol thanks again

jj1562

it sure is! Thanks for the input

F1Addict

While you're in there, check the bolts at the back of the valve cover. They're tough to get to and a lot of shadetrees don't make the effort to properly torque them when replacing the valve cover. It's a prime spot for a leak that will, in time, mimic a bad RMS.

Bustedback

My money is on the oil filter adaptor.

BrandonSS

while we are talking about it, whats the proper tq for the valve cover bolts?

jj1562

dry as a bone

cruiser54

55 INCH pounds

jj1562

at this time, I would like to stand up and tell everyone I'm an IDIOT! lol, I looked at the oil filter and saw it was dry up top and I guess dead set on the RMS, after installing the tranny cooler, I went on to tighten the oil pan bolts and give a better look around underneath, WOW! Holy oil batman on the bottom side of the oil filter, through the wrench on it and got just about 1 full turn to tight, fingers crossed that's what it was, going to spray it down now with some degreaser and watch it the next few days or so. Thanks again to all that pitched in and gave some advice, back to the simple stuff thinking process!

cruiser54

Not an idiot, and you're willing to admit you're wrong!!

That's why my write-up says "with a good set of eyes and a dim flashlight" that anyone can properly diagnose their oil leaks. LOL.

Glad you found it.

Bustedback wins the internet cookie for the best guess.

jj1562

Don't give out any prizes just yet, lol I'll see in a few days or so and see if it stopped leaking