Rear Main Seal, 3.8

R

RacerX10

New member
2008 JKU .. I'm about to swap in a low miles salvage transmission, and I think I'll be replacing the rear main seal while I'm in there. I do have a leak down there but I'm not sure if it's the oil pan gasket or the rear main seal, so I'm doing both. 200,000 miles on the motor.

Anyway, the replacement rear main seal parts I see appear to come as a stamped-steel assembly with the seal already in it, but the factory rear main seal assembly looks like (from the photos I've seen) a cast aluminum part.

Anybody ever swapped this before ? Seems like the cast part would be better.

Thoughts ?
 
Sorry, haven't had an RMS leak on any of my JK's or at least, as of yet. Are you saying that the OE part looks different or are you looking at an aftermarket RMS?
 
Just did mine while my transmission was out. I used a fel-pro set and it looked just like what was on it. They were both stamped steel. I bought my jeep used with 50k on it so I don't know for sure it was the original, but I would think it probably was.


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Curious. I haven't actually put eyes on mine yet, but what I've read indicates the original deal looks like this :

s-l1600.jpg

Whereas the stuff you buy new now is the stamped steel part :

232385.jpg
 
QuicksilverJK said:
Just did mine while my transmission was out. I used a fel-pro set and it looked just like what was on it. They were both stamped steel. I bought my jeep used with 50k on it so I don't know for sure it was the original, but I would think it probably was.


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Click to expand...

Did you use any silicone anywhere with that fel pro set, or just the cardboard gasket that it seems to ship with ?

Also, can you tell me if the top two bolts on the bellhousing have that E12 external Torx head on it? Need to know if I have to pick up one of those sockets to pull this transmission.
 
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Could be a year thing. A lot of parts changed in 2009 in an effort to save Chrysler from going under.
 
RacerX10 said:
Did you use any silicone anywhere with that fel pro set, or just the cardboard gasket that it seems to ship with ?

Also, can you tell me if the top two bolts on the bellhousing have that E12 external Torx head on it? Need to know if I have to pick up one of those sockets to pull this transmission.
Click to expand...

I used a little silicone on the bottom corners where the flat piece and the oil pan gasket meat. (The bottom flat is the sealing surface for the oil pan.) I was doing oil pan gasket at the same time. My top bolts were 18mm hex head.


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QuicksilverJK said:
I used a little silicone on the bottom corners where the flat piece and the oil pan gasket meat. (The bottom flat is the sealing surface for the oil pan.) I was doing oil pan gasket at the same time. My top bolts were 18mm hex head.


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Click to expand...

ok ive hit a bit of a delimma. this fel pro rear main seal came with a cardboard gasket to go behind the rear main seal carrier, as shown here :

41ODQN4qLVL._SY300_.jpg

but when i pulled the original part of the motor (2008 3.8) it did not have that cardboard seal behind it.

the carrier has a built in rubber seal that goes all the way around, and if i use that cardboard seal i'd have a gasket on top of a gasket, which is generally a no no. i don't wanna screw this job up because i'm in WAY deep to have gotten to this part :)

what did you do quicksilver ? use the cardboard seal that comes with the fel pro part or discard ? btw mine was just like yours, the stamped steel part (not the cast aluminum from the first post)

thanks for your thoughts.
 
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By now I'm sure you have made a decision and done it. I had the same dilemma when I did mine. Ultimately I decided that it wouldn't be in the kit if it wasn't needed. I used a little gaskicinch (probably butcher that spelling) and so far no signs of a leak. I'm sure that either way you go you will be fine.


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I just got off the phone with Fel-Pro. Their tech guys said to discard that extra cardboard gasket that comes with it.

YMMV ¯\_(ツ)_/¯
 
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