2004 LJ rear main seal replacement

[KP_LJ]

Good morning . Started working on replacing the rear main and transmission oil pan seals on my 04 LJ. Anything I need to consider to work\replace while working on this?

So far ordered the seals and including the transmission oil filer.

160K miles on the jeep

I'm following this detailed thread from @Chris. Thank you
https://wranglertjforum.com/threads/rear-main-seal-replacement-4-0.826/

 

[macleanflood]

I did my oil pump while I was in there...took me four attempts and a Mopar, not Felpro seal and a lot of the red Loctite on the mating surface.

Also check your timing chain...you can just reach it with a finger and see if it's too loose and needs replaced.

-Mac

 

[JMT]

There are a number of "tips" people have given for the RMS. Results vary. A couple of things I'd suggest.

1. Use the Fel-Pro tool to insert the upper RMS seal. Without it you'll almost inevitably cut a tiny sliver on the seal and it is wasted at that point.
2. Clean every surface religiously before
3. Add some gear oil (heavier weight than regular oil) to the upper seal so when you slide it in it has some lubrication to slide in easier.
4. Make sure and spread the anaerobic gasket sealer correctly on the mating surfaces. I'd post a pic but I don't have one on this computer. Find one!
5. Don't fill with oil and run for 24 hours. This allows the anaerobic gasket maker and oil pan RTV to cure adequately. and avoid a leak.
6. I cocked my Fel-Pro RMS so that about 70% went into the upper and 30% was in the lower and vice versa for the other side of the seal. If you do this put some anaerobic sealer where the two sides of the seal meet. YMMV.

 

[Sgt Jarhead]

A forum member had mentioned using chop sticks to remove the upper rear main seal which I thought is a smart move to avoid damaging/nicking anything in the process.

 

[KP_LJ]

A forum member had mentioned using chop sticks to remove the upper rear main seal which I thought is a smart move to avoid damaging/nicking anything in the process.

I saw that video. Really helpful info.

Thank you @JMT and @macleanflood
Currently, I'm working on taking off the catalytic converter bolts. So far I removed one bolt out of 4 and using 14 flex socket.

 

[Sgt Jarhead]

I saw that video. Really helpful info.

Thank you @JMT and @macleanflood
Currently, I'm working on taking off the catalytic converter bolts. So far I removed one bolt out of 4 and using 14 flex socket.

If you have a ratcheting wrench that helped me remove all of mine. There should be a heat shield in the area that you can physically push out of the way to make a little more room.

 

[JMT]

I saw that video. Really helpful info.

Thank you @JMT and @macleanflood
Currently, I'm working on taking off the catalytic converter bolts. So far I removed one bolt out of 4 and using 14 flex socket.

I got three of them from the bottom and one from the top. I only needed an extension on a 3/8" socket wrench to get three. I used the impact to remove. The one I had to get from the top is the second bolt from the front of the engine working back.

When you put them back on, get one started by hand (PITA), and then put a socket wrench on it for a bit more, but don't tighten all the way. Then get the other three started and do the same. Finally tighten them all up making sure the cats are centered on the manifold. They will usually fall in place. Make sure the cats are not touching the oil pan. You should have about 3/4 to 1" of space between them at the closest point.

 

[Duck Doctor]

The anaerobic gasket sealer is a key component to a successful install. Also agree with JMT about not immediately filling with oil. I had the luxury of waiting a couple weeks, which likely helped the RMS sealant and oil pan sealant cure.

 

[KP_LJ]

If you have a ratcheting wrench that helped me remove all of mine. There should be a heat shield in the area that you can physically push out of the way to make a little more room.

This seems like little different on my Jeep. Not seeing any shield on it. The one I took off has a NUT on the other side. The remaining three have lock washers on them and two washers are not in good shape. One bolt required a 13mm or less than 14mm socket it seems.

 

[KP_LJ]

Spent a good amount of time last night. 3 bolts came out. The last one seems like a cutting job.

 

[macleanflood]

Spent a good amount of time last night. 3 bolts came out. The last one seems like a cutting job.

Why I like my 97... exhaust is super simple. When I did my neighbor's 04 WJ 4.0 head I spent more time on the exhaust then swapping the head gasket.

Gas axe for the win! You can do it!

-Mac

 

[JMT]

Spent a good amount of time last night. 3 bolts came out. The last one seems like a cutting job.

replace all four lock nuts and bolts. Use antiseize. I may have a link somewhere. I’ll report back.

 

[JMT]

@KP_LJ link to the u nuts.

https://www.ebay.com/itm/1917424365...pid=5337789113&customid=&toolid=10001&mkevt=1

 

[KP_LJ]

Thank you @JMT These are the same lock nuts I dealt with. They broke easily while taking them off. I had to use a plier on the other end. Any good alternatives?

 

[macleanflood]

replace all four lock nuts and bolts. Use antiseize. I may have a link somewhere. I’ll report back.

Why bother with antisieze? I slather it on everything but exhaust...I fully expect to have to cut off bolts and I don't want them wiggling loose and burning holes in my clutch line!

-Mac

 

[JMT]

Why bother with antisieze? I slather it on everything but exhaust...I fully expect to have to cut off bolts and I don't want them wiggling loose and burning holes in my clutch line!

View attachment 507426

-Mac

I was actually reading about proper use of antiseize last night and the article described where to use it and where not to use it. One place it mentioned to use was manifold. It said high heat accelerates corrosion.

https://blog.fcpeuro.com/6-tips-for-effective-use-of-anti-seize

Don’t ask why I’m reading about anti-seize, but it has to do with a mod that would require a lot of it due to mixing two metals.

 

[macleanflood]

High heat applications like exhaust also dictates heat resistant antisieze like copper...not your typical aluminum based stuff.

-Mac

 

[JMT]

High heat applications like exhaust also dictates heat resistant antisieze like copper...not your typical aluminum based stuff.

-Mac

While not knowing the heat characteristics of aluminum vs copper anti-seize, I started using copper five years ago.

 

[por212]

Are you sure your oil leak is coming from your main seal? Seem to me from the pictures you have a lot of oil up high on your exhaust which could indicate a leak somewhere from the top of your engine.

 

[JMT]

CCV and/or PCV are common oil leak locations.