Rear Main leak

I searched for tips on replacing my rear main seal and I still have some questions.

I've got a 99 Sport with an auto tranny.

My friend who is a mechanic is convinced that for me to replace the seal I'll have to seperate the tranny from the engine to get at it (even though he's never replaced one on a late model XJ). Is this true or am I simply going to be able to drop the pan and swap out the seal?

Matt

Just drop the pan. Good write-up at www.jeepin.com/features/rearmain/index.asp

I did this last winter on my 1999 XJ. No need to remove the tranny. Just drop the pan and the rear main cap.

However, it would have been nice if the tranny and flywheel were removed, so I could make sure the rear of the pan gasket was in place properly. It goes in blind, so good luck back there.

That's what I thought...thanks for the input guys...I just couldn't see why, other than ease of installation, that the tranny would have to be moved...

looks like I've got a new project for next weekend...

Matt

When I did my previous XJ, I used the 4-piece Fel-Pro pan gasket. Big mistake. The main seal worked fine and the gasket hemorrhaged for months until it either swelled up or filled with sludge enough to slow down to a tolerable trickle. Whatever a Mopar 1-piece gasket costs, I'll use it next time (my current XJ is way overdue for a seal too).

It's good to have a fair amount of lift up front. If you don't have anough and have a problem clearing the pan when pulling it out or putting it in, take your hihglift and raise by the front bumper not to the point of lifting the wheels of the ground but just so that your front end goes up and gives you more room above the axle.

Matthew Currie said:

When I did my previous XJ, I used the 4-piece Fel-Pro pan gasket. Big mistake. The main seal worked fine and the gasket hemorrhaged for months until it either swelled up or filled with sludge enough to slow down to a tolerable trickle. Whatever a Mopar 1-piece gasket costs, I'll use it next time (my current XJ is way overdue for a seal too).

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ONE PIECE? WHOA!! assgas: That means drop the crank and pull the xmssn!! Way too much work- stay with the two piece type they have worked for 50 years. Hasta

willysnut said:

ONE PIECE? WHOA!! assgas: That means drop the crank and pull the xmssn!! Way too much work- stay with the two piece type they have worked for 50 years. Hasta

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I used one piece and it was easy! Why would I have to pull the crank and the tranny to put a one piece oil pan gasket??

willysnut said:

ONE PIECE? WHOA!! assgas: That means drop the crank and pull the xmssn!! Way too much work- stay with the two piece type they have worked for 50 years. Hasta

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one piece oil pan gasket, not rear main seal.

Kejtar said:

It's good to have a fair amount of lift up front. If you don't have anough and have a problem clearing the pan when pulling it out or putting it in, take your hihglift and raise by the front bumper not to the point of lifting the wheels of the ground but just so that your front end goes up and gives you more room above the axle.

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Lifting the front is a good idea. I haven't done this job yet, and need to, but the pan to axle clearance looks really tight. I'd recommend lifting the vehicle with a hydraulic from underneath, then installing jack stands. Think I'd lift it to the point where the wheels are off the ground and maybe even remove them just to get a little light and access under the vehicle. In any event I would not use a hi-lift jack to lift except if I absolutely had to and would never crawl under a jacked vehicle, especially a hi-lift jacked one.

mhead said:

In any event I would not use a hi-lift jack to lift except if I absolutely had to and would never crawl under a jacked vehicle, especially a hi-lift jacked one.

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Even though I removed the pan without using a hilift all I needed was about 1/2" to comfortably put it back in and not worry about sliding thing off or damaging it. Anyways good point: going under a vehicle that's lifted with a hilift is a bad idea, while what I did was just relieve some of the weight from the front end and I still had it sitting firmly on the ground.

willysnut said:

ONE PIECE? WHOA!! assgas: That means drop the crank and pull the xmssn!! Way too much work- stay with the two piece type they have worked for 50 years. Hasta

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Pan gasket I'm talking about, not seal. The seal is two piece, and FelPro makes a really nice one with a double lip that works well. But the 4- piece pan gasket is a mess.

Do you know if any of the parts chains carry fel-pro of do I have to order the double liped seal from q-tec? And I can just get the MOPAR one peice at a dealer ship, right?
-Steve D

StuckXJ said:

Do you know if any of the parts chains carry fel-pro of do I have to order the double liped seal from q-tec? And I can just get the MOPAR one peice at a dealer ship, right?
-Steve D

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I know for a fact the napa carries felpro. Thats one of the rare occasions that I use napa with it's 'banking hours for business' mentality... They are never open when I need them.

Advance Auto has felpro I just did this the other weekend. Also if you have a lift but don't have longer lower control arms it's gonna be tough. The further you drop the axle the further back it will go unless you take off the control arms.

RichP said:

I know for a fact the napa carries felpro. Thats one of the rare occasions that I use napa with it's 'banking hours for business' mentality... They are never open when I need them.

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When I grow up, I am going to own a NAPA store. Not to sell parts to customers, mind you, just for me to get the parts I need whenever I need them!!

I did my rear seal last weekend on a '92 I-6 Auto trans

Got a good gasket (think it was Fel-pro) from Pep Boys. It was a complete rubber kind and went all the way around the pan without any gaps. Seemed to be well designed.

Lifted the car onto stands and removed the wheels. Undid the pan bolts. Pan came loose from engine easily, it just dropped off under its own weight.
Pan jammed between starter motor and exhaust down tube.
Choose to loosen down tube from manifold which worked ok. Didn't remove starter motor.
Still had trouble so slightly jacked front axle with two floor jacks, removed lower shock absorber connections, the let axle down as far as it would go. It jams the quadralinks, but lower than the shocks will allow. Also unbolted stabilizer.
Pan came right out.
Removed rear bearing cap.

Here's the part where the upper seal is removed. Look at the lower seal that comes out with the bearing cap. It's shot so cut it up a little. Find the wire inside it. The same size wire is in the upper seal. Find a punch of the same diameter. Be sure it's not any larger or much smaller. Tape this into the insert end (square cavity) of a long 3/8" drive socket extension. This will allow you to hit the extension below the trans bell housing. Tape will simply keep the punch from falling out each stroke.

Put the punch against the end of the upper seal and gently tap way gently until the rubber of the seal is mushed and you can see the end of the wire within the seal.

I was confused at this point and couldn't see the seal well enough to be sure I wasn't punching against the block somehow and not the seal. I used a smaller punch which wound up jamming between the wire within the seal and the crank. It scratched the crank badly. I'm a lucky boy since the scratch happend to be outside the point where the seal lip rides on the crank. If it was just 1/8 over, well I'd never be sealing THAT engine. Be really careful only to punch against the end of the wire within the seal.

I used a 2 pound hammer and got scared that I was somehow hitting the wrong place. It's crowded under the vehicle and I couldn't swing very hard. I got more desprate after I f'd up. The trick is to use a 5 pound drilling hammer. It takes a substantial amount of mass to initially break the seal loose. Wish I had known that before hand since it was really easy to get the seal loose. Just locate the end of the wire within the seal, put the punch accurately against the end. And 1 sharp wack and the seal is loose.

Seal came out easily after it loosened. New seal went in easily.

There are some instructions at the URL in this post about placing sealant on the bearing cap. Did this after buying correct sealant from Pepboys. I had to make a special trip.

My pan gasket wouldn't stay in place so I glued it on with a different Permetex gasket gook - one designed to hold the gasket in place. Only did the side against the pan. Made it easy to get the pan back up to the engine without the gasket falling off.

Pretty routine from this point. The URL was right on.

Vehicle doesn't leak oil now. (Whew!)

Took me about 8 hours including a 1 hour trip to Pep Boys.
PITA...

what is an easy way to tell if you have a rear main leak? i have a new oil pan gasket i am putting in, do you think i maybe am fixing the wrong part?

Clean off the negine well and check it out. You might see oil coming out from behind the flywheel dust cover. Although, if your gasket was leaking at the rear of teh engine then it would be hard to tell teh difference. If you are changing the oil pan gasket I would probably go ahead and do the rear main if you have not done it. You would have already have done the hard work and would only require removing two more bolts.

I agree... definitely do the rear main if you are doing the pan. That said, I guess it doesn't matter which is leaking!