Rear Main Seal Replacement (4.0)
- Thread starter Chris
- Start date
Rubicon John
TJ Enthusiast
Does the other half of the seal get offset?
what is the purpose of offsetting this half of the seal? Does it get pushed back into place when you install the bearing cap?
I’m going to be tackling this job soon and my only experience is with 1 piece seals so I’m looking for all the advice I can get so this goes smoothly. Thanks.
Yup this is the one I followed both times and have still leaked both times. Must be something different as I have the newer type seal in a 2001. I’m going to try and follow someone who said to rotate the seal so it’s offset and try that way. Your write up is good just for some reason didn’t work for me
thanks
I am so sorry this didn't work out for you. All I was trying to do is help the community, not mis-lead them so that they would another leak. Also the write up is based on the FSM but with pictures.
I feel that the design is inherently flawed and the offsetting the seal is literally to "offset" the design flaw.
One thing that I do for my repairs is that whenever I apply any RTVs or any adhesives I make sure the mating surface is free of oil or any debris to a point paint will stick to it and that won't come off.
HTH.
The purpose of the offsetting the seal is to relocate the joints where the mating surfaces of the seal is away from the mating surfaces of the bearing cap.
Some movement will occur between bearing cap and the block. By keeping the seal joint away from the area, you have better chance of keeping the oil on the right side.
Rubicon John
TJ Enthusiast
This is a good explanation and makes a lot of sense. Thank you. But does the upper half of the seal also get installed with a matching offset?
Rubicon John
TJ Enthusiast
Rubicon John
TJ Enthusiast
Unless the idea was for the seal to slide into place when the bearing cap was installed. But now I get that isn’t the idea.
Pcleaners2
TJ Enthusiast
This write up was done really well but it is just a crappy design . I’d rather pull trans and have a one piece seal. Lol
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Pcleaners2
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reichlejj
New Member
Tackling replacing the RMS right now but how do you remove these bolts closest to the tranny?? The bolt heads are partially covered up?
I am not 100% familiar with this exact task- but I would bend or trim that tab to get access to them, than if need be bend back into place. I cants see what trimming them would hurt myself
reichlejj
New Member
I'm removing the oil pan to get replace the rear main seal. This is where the tranny connects and where the RMS is so I'm hesitant about damaging this part to get to the bolt heads.
Rubicon John
TJ Enthusiast
That rubber piece is a bit swollen from all the leaked oil that has saturated it. It’s not actually sealing anything. I just did mine a couple weeks ago - just use an extension and a socket and apply some pressure and the socket will go around the bolt head. You won’t damage anything.
reichlejj
New Member
Copy that. I'm not sure it is rubber
But I'll take another crack at it tomorrow and put some more pressure on it. BTW this is on a 2006 TJ, not sure if that makes a difference.
Rubicon John
TJ Enthusiast
You’ll be ok. It’s the same design as my 04, as my friend just did his 06 this past week, coincidentally.Copy that. I'm not sure it is rubber
I just broke a little bit of the rubber to get to the bolt. The seal is on backorder at the moment, none available for months.
Great write up! I'm in the middle of replacing a manifold/exhaust gasket anyway and figured while I have everything out I might as well get this done too. Also got a new valve cover gasket. Contemplating on the oil pump while I'm in there. I have a lift in my shop which has been an incredible help with everything. My body and bones got tired of the cold concrete. Been there done that. One thing I told my wife when we decided to build a new house....I need a shop. Very fortunate to turn it into what I've always dreamed 
