I own a 04 LJ 4.0 with a 42RLE Trans and I need to replace my oil pan and and gasket because it is leaking but I am wondering since I am already going to be under there should I go ahead and replace the rear main even though it isn’t leaking? Please help thank you.
Should I replace my rear main since I need to change my oil pan gasket?
- Thread starter Tzerambo
- Start date
I would not touch it if it is not leaking, many people have changed it only to have it leak again.
OHFIVETJ
TJ Addict
I dunno, to me it's like having to do internal tranny work on a manual transmission & not changing a 10 year old 40,000 mi clutch because you have no issues with it. I say while your in there do it , but I'm sure that there is a DR. out there that will comment and say, that while doing open heart surgery you don't do a kidney transplant too just because your in there 
Last edited:
89grand
TJ Addict
Yeah that’s what I was think I don’t wanna open a can of wormsI dunno, to me it's like having to do internal tranny work on a manual transmission & not changing a 10 year old 40,000 mi clutch because you have no issues with it. I say while your in there do it , but I'm sure that there is a DR. out there that will comment and say, that while doing open heart surgery you don't do a kidney transplant too just because your in there
When you took your oil pan off do you have to take any exhaust components off or can it just slide right out.
My 03 i had to drop the exhaust pipe out of the way to drop the oil pan. i was able to leave the starter in place though.
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
Same here on my ‘06.
soak the bolt’s that hold the mini cats with kroil or a 50/50 mix of auto trans fluid and acetone. Let it soak overnight at least.
As far as the RMS, I agree with those that say leave it alone if it’s not leaking. I thought I had one leaking so I started the job. Once I got the oil pan off, I could clearly see the oil pan gasket was the cause of the leak at the back of the pan. I debated doing the RMS since I was in there but didn’t. 2-1/2 years later and still no leaks.
While you have the pan off, you can look up in there and look at the OPDA gear and see if you have any wear. I was able to see mine very well and it and the cam gear looked good. Good for peace of mind. : )
89grand
TJ Addict
You have to disconnect some of the exhaust unfortunately. I figured due to that amount of work, I should replace the RMS...and you know, I probably shouldn't have.
I thought I had an RMS leak, but after inspecting things closely, I'm fairly certain that it's coming from the oil pan gasket. I feel like I should clean everything and check for a RMS leak before I start the job. Will a RMS leak be obvious and different enough to detect from an oil pan gasket leak (assuming everything is clean to start)?
After you disconnect the bolts holding the mini-cats, do you also disconnect farther downstream and completely remove that section of the exhaust? I'm assuming you can't just let it hang, but I'm new to working on the TJ.
Please share any other been there, done that's and tips for this job!
After you disconnect the bolts holding the mini-cats, do you also disconnect farther downstream and completely remove that section of the exhaust? I'm assuming you can't just let it hang, but I'm new to working on the TJ.
Please share any other been there, done that's and tips for this job!
The best way to spot a leak is to clean everything around the area it’s leaking from , then let it run for a little bit and then shut it off and immediately get under it and look to see any leaks. If your really not sure where it’s coming from just take it to a trusted mechanic near by not firestone or jiffy lube take it to good mechanic that works on engines and transmissions not a tire shop, and ask them if they can tell you where it’s leaking from. Then you can go ahead and replace what is needed. I have never taken the exhaust off my tj yet because Mines rusty as hell but any time I do something and don’t know exactly how it comes off I just use a Jeep Haynes repair manual for Wranglers they usually give me a good idea of what I need to do.