Rear Main seal and oil pan gasket replacement.
 

The rear seal leaks and leaves drops of oil on the floor, And the bottom end is all oily as hell..So I'm thinking of replacing the seal and the oilpan gasket this weekend, Maybe stick a new oil pump in her while i'm there too..
My problem is the motor has 200K on it and I hate to do all that work for a leak on an old motor. But I cant stand a leaking engine and I cant afford to do a complete rebuild right now. I would like to find a donor motor and build one for it so I can just do a swap when it's ready, But again the Money says NOT!...
So What to Do What To Do???

Anyway, Has anyone done this on the 4.0 ? The seal is two piece right ?? So it can be changed without pulling the tranny??

2 peice seals are realy easy to change and well worth the money in oil alone depending on how bad it leaks but im not sure if it is a 2 peice or not.

Hey......before you go through that trouble.....check one thing first....saved me a helluva headache....cause I saw a terrible mess and oil hangin from the tranny plate and all.................
Make sure your valve cover gasket isn't leaking...........that was MY issue.
I replaced the gasket....and the drips stop....seems like over time...the factory gasket fails...and the grommets loose their holding power...check this first before diving into a much more complicated fix....
Just my 2 cents.......
Scott

Here ya go, Full detailed write-up

http://www.jeepin.com/features/rearmain/

Cool, Thanks Guys !!

I will check the valve cover since it could be just running down the back of the motor !!

Thanks for the Link !

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That's an awesome write-up!


I recently started a thread on another forum and the responses that i got on replacing the Oil Pump was... don't.

After thinking about it, i had to kinda agree. Replacing the pump at 200K will give me just enough oil pressure to blast fresh oil out of just every seal and gasket imaginable, ya know?

I'm still debating on replacing the Rear Main Seal and Pan Gasket this week-end, while i have the motor torn down to replace my Header and Motor Mounts. I have a 3" lift and the motor will be jacked up already...

Might just wait 'til i replace my Front Axle in the spring, when i'll have WAY easy access to the pan. :001_unsure:



And oh yeah... i think the back of my Valve Cover is dripping oil down the back of my motor as well!

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I just replaced the two peace seal, they are not bad, just follow the directions that 1SickCherokee posted, very good directions. But I would check valve cover gasket first I have seen valve cover gasket leaking and looks like the rear seal.

What ever oil leaks you have now will be the same if you replace them pump...I would absolutly replace the pump if you have it apart. dont buy into that horse crap.....Gear pumps pick up the Unfiltered Dirty oil from the bottom of the pan.....

Thanks for your opinion, i'll add it to the several dozen that i already have. :p


:rofl:

AFAIK, the oil pump never directs pressurized oil at any seal, or gasket. The oil goes thru passages to the main and rod rearings, and lifter galley, and then splashed everywhere. There are slingers or other devices to reduce the oil that actually gets to a seal on a shaft.
Replace the pump.

True, and In most cases the oil goes to the main bearings first, And if they have a lot of clearance the oil Bleeding will limit pressure to the to top end etc. So a new pump shouldn't hurt anything....??

I know this...that is where i was going with my comment...but you just cant tell some people anything.

Pull the starter?

i have done this fix on a 90 XJ and 95 ZJ however the exhaust setup is way diff on my 01 XJ and I am unable to get to 3 or 4 of the oil pan bolts due to "pre cats" in the way just below header? anyways anyone done this to this year XJ? tips would be great. one of my oil leaks was the oil filter adaptor o-ring.

I have a 92 briarwood. I've been trying to do the rear main seal on. It has been leaking onto my exhaust and smoking. I've already replaced the valve cover gasket and the oil pressure sending unit both were leaking like crazy. That didn't fix it so I went onto the rear main. I was able to get the oil pan off with little issue and i was able to get the bottom half of the seal out no problem. Now the top half is a different story. I've used wooden dowels, punches, screwdrivers, pushing and hammering on the the wire in the top half of the seal but it still wont come out. Has any one else had this problem? If so any advice?

I always loosen all of the main cap bolts when I'm doing the top part of a two piece seal.

Great info in here. I just replaced the valve cover gasket and I still have a teardrop leak at the very bottom of the motor. Might have to change my seal.

he was correct. there should be little if any difference in pressure between a new and used pump provided the used pump is functioning correctly.

also oil leaks are caused by hard gaskets and or excessive crankcase pressure. an oil pump will have no bearing on if you do or do not leak oil

I don't mean to hijack but I think mine leaks to but only when I pull my band trailer. Has anybody had a leak when pulling?

I admit I only skimmed over this thread. :jester:

A leaking oil filter adapter can look just like a rear main leaking, the oil blows around. To see you might clean things well, then watch closely. (a rear main might leak if the crank moved over a tad).. I like this one, clicking on the pics expands them...>>>

http://www.myjeepxj.com/cherokee-rep...filter-adapter

Did some digging and this thread seemed like a good place to post my question. I was told by a jeep mechanic that changing the rear main seal on a high mileage cherokee has a 50/50 success rate. He explained that the old seals harden and overtime, create a groove in the metal. This will cause a new seal to fail as well and possibly make things worse.

How true is this statement because I know for a fact my rear main seal and oil pan gasket are busted and with 153k on the motor I'm worried my XJ might be close to demise.

He also quoted me $500 to replace rear main and oil pan gasket. Im thinking oil pan gasket is easy to change whereas the rear main would be more difficult. Ive done valve cover, oil filter O ring, and tranny pan myself so I might give this a go if replacing my rear main doesn't have a 50% chance of making things worse. I appreciate the help.

All I can say is 150K is not really high for the 4.0. One of mine is fine, strong and healthy at over 280K, and another just went past 200K. Nether has much blow-by, both get over 20 on the highway. The one at 200....I suspect it's rear main is leaking because someone botched the replacement when it needed oil filter adapter O rings.

Do be sure the large 1/2 inch tube from the valve cover to the air cleaner is free and un restricted. People do goofy things...an aftermarket filter or a smaller tube can cause crank-case pressure that will make it blow oil out where it can. RM, front seal, dizzy and or the dipstick/valve cover.

My parts are sitting here waiting, I haven't done a RM on a 4.0, but soon. I intend to disconnect the shocks and let the front axle hang, and unbolting only the rear bearing cap, use a drinking straw and dish soap to feed the new seal in without boogieing it up.....

Yes I certainly hope my XJ is only halfway through its lifespan. But if the rear main has the groove like I was told about Idk what more can be done. I asked him about an expanding foam type seal and he told me he doesnt believe there is anything like that for a RM. Some of the other aftermarket gaskets are made for older worn out vehicles but not the RM.

Im a bit worried to attempt the RM in the first place and now that I know about the possibility of this issue I dont think I will attempt to change it. The straw dishsoap method sounds wonderful too bad you dont live near me :) There used to be a few drops of oil on the pavement directly under the front of the motor below the largest pully that holds the serp belt but i think thats from the oil pan gasket. Aside from that shes stopped dripping on her own and the oil level is always good. im going to clean it up nice and inspect the rear main. Hopefully all the mess is from the oil pan gasket and making its way back.That would be my saving grace.

At what point in time does a rear main usually go? Is it possible an OE rear main can last well past 150k miles?

Edit: I changed the rubber sleeve on the 1/2 tube from valve cover to air box bc the old one was cracked. I also changed the elbow and grommet on the front and back of valve cover... Hope that didnt cause any harm hmm but it seems like that area is all sound no oil in air box and tight seals.

universal joint sockets. I have the precats on my '01 and had no problem with the swivel and some extensions

A couple of years ago I bought a pan gasket and RM for "Brown" the one pushen 300K. Turned out there was a kink in the tube I had venting the VC, so I returned the parts I'd bought.

I live in the sticks where it's all dirt and gravel. Back when I waz working some, I'd carry a piece of cardboard for if I needed to park on someones pristine, clean concrete driveway. It drips very little, but sometimes even that is not welcome. It needs less than a Qt per 1000 miles, so there is that. I have no intention of going after every little drip.

"White" on the other hand is pissen, and it gets on the exhaust crossover. When I hit my hill coming home, (1,500 foot climb in 3 miles), that pipe gets hot and I leave a cloud of smoke. The Castriol I use is about $5 a quart and it's leaking around a quart/tank. Getting on that soon..weather is now OK but I'm loaning Brown to a neighbor, so no spare wheels for a town trip.

I hear some stories where replacing the RMS does not fix the leak and others who say it'll come back in a year. I've done the RMS on each of my XJ's. I did the 97 XJ at about 197,000 miles a year ago and its been leak free. I just did the 01 XJ at 340,000 miles and its still dry. If the crank is not worn then it will probably hold just fine. Some tips & suggestions:

1. I used the drinking straw & soap on the back of the seal and oil on the lip technique.

2. Use a BRASS PUNCH to drive out the upper seal. Yes, the brass punches may bend, but you can straighten them out. Its far cheaper to use a brass punch than accidentally gouge your crankshaft.

3. For the pan gasket, RTV is needed in 4-6 locations. I put it at the bends around the front cover and rear bearing cap, and also where the block meets the front cover.

4. Use studs to hold the oil pan gasket in place against the block and press it into place around the rear main cap. Then you just put the pan over the studs and start installing bolts working from center out.

5. Torque spec is 84 in-lbs for the smaller bolts and 132 in-lbs for the larger ones.

6. Consider using Vibra-tite or some other means of holding the bolts from vibrating loose. I hear weathering stripping adhesive also works. There is probably something in your toolbox that will help. The only leak I had on my 97 XJ was from the front cover bolts backing out. Adding Vibra-tite solved that problem.

7. Rear main bearing cap and block surface get small dabs of anaerobic sealer. Its red and perfectly suitable for applying directly to the block and cap. Check the FSM for more information.

8. On a stock XJ, I strongly suggest removing the sway bar at the body side, track bar from the frame, and steering dampener from the drag link. Then jack up the body and let the axle droop low. There will be enough room. Shocks should not need to be disconnected but can be if needed. If your XJ is lifted you may not need to do all of these things.

gvnc,

Glad the universal sockets are working out for you.

DFlintsone,

I'd suggest getting in there in doing it.

Chonson,

I don't know how frequently they go. My 01 XJ started weeping around 160-180,000. I've heard of them leaking as early as 75,000. I decided to change the cats when I had all of this apart on my 01 XJ. If the cats are touching the oil pan then they were probably whacked at some point. You should be able to slip your finger between the cat pipe and the oil pan. That was part of my problem. The cat pipes were resting on the oil pan so I couldn't get to the oil pan bolts. As far as the cats, that's where the universal sockets come in. For the 4 flange bolts up near the manifold.

great tips. in relation to #8, the FSM says to unbolt the engine mounts and raise the engine for clearance supporting the crank pulley with a jack stand. anyone have success doing it that way?

Question
 

So I recently replace the oil pump and screen and the oil pan gasket and I didn't get to do the rear main seal so my question is do i have to replace the oil pan gasket again if I re-drop it to replace rear main maybe have a 100 miles on it since new gasket

You have a Jeep that leaks oil? Same. actually. Don't we all have a Jeep that leaks oil? Lol. Anyways I will be doing the rear main seal, VC gasket because it's leaking all around and oil pan gasket and moving over to good ol Rotella. I have an 89 Jeep and was wondering if it might not be a bad idea to pick the valve cover off of a 91+ XJ because it uses grommets and I should have less chance of incorrectly mounting the VC and springing another leak which I heard isn't too hard to do on Renix valve covers. I also believe it has a bit more clearance on the inside. Has anyone done that swap?

I just installed one of those supper one piece blue gaskets, probably Felpro, first one I'd seen. Just maybe if alter I got it out it looked good to go, (cleanupable), I might re-use it. Because of the hassle, if it's different, cork or something, probably not.