Bad rear main seal on a 3.6?

W

WhoDoesThat

Member
I've noticed a very small amount of oil leaking from the bottom vent of my transmission. I searched through various threads and the symptoms point to the rear main seal, although those threads were for the 3.8. There hasn't been many reports of them going bad on a 3.6. My Jeep is already past the warranty period, so I can't get it covered. I can say that it is a really slow leak as I've observed my oil level for the past few weeks and haven't noted any change. Has anyone had to do this seal on their own? Or, is there something I should add to the oil to hopefully seal it back up considering its a slow leak?
 
im only third rear main seal. and its leaking again. waiting for it to get nasty and at least drip on the floor.last time it was replaced the tech said it wasn't the seal but I don't know what it actually can be.
 
More likely your oil filter/cooler housing has a leak. Look in the valley on top of the engine and see if there is any oil up there.
 
both the oil housing and rear main seal leaked on mine. Lucky that both time was replaced under warranty.
 
waiting for #3 on my '15 , they are on back order.

I have been waiting 3 month for the new one already. maybe sometime in June if I am lucky.
 
ive has my oil cooler replaced a few months back as well. starting to think mine just might not be main seal but can't figure where its coming from. drivers side I can see oil seepage up the bell little then vanish. then pooling up at the inspection plugs. need X-ray eyes,lol
 
Dealer replaced my oil cooler, then 2700 miles later the new one started to leak...


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This thread is getting old I know but the OP brings up a good point that some year model JKs seem to have a fairly common RMS leak but there is not a lot of detailed info out there.

My 13 just developed a leak noticed at the bell housing. Fairly minor. May have begun after lots of highway miles in 90+ heat in July. I do use Mobil 1.

Cleaned it off, drove it. Repeat. Leak is at the bell housing only. No leaks around the front or top of the engine by the oil filter housing or the heads. Spoke with my very trusted mechanic. Recommended RMS and clutch at the same time as mine is starting to get chattery at times. He was upfront that it may happen again and that he's seen it more than a few times on 4.0 TJs and almost every year JK. He did say I could just ignore it until it gets real bad or my clutch starts slipping big time. I just have a problem with leaks on fairly new vehicles so no way.

RMS from felpro is about $60 (OEM a little less), OEM clutch $400ish + TOB (be careful on the TOB...MOPAR is recommended by most) etc and lots of labor to get everything off/down and back on the right way. Im just glad my JK is not all rusted together and that will help.

Some of what Ive seen on the newer 3.6 JKs seems like jeeps with very low miles are having this issue. Some of the 14-15 JK's also seem to have a more specific leak at the front/top of the engine that is being confused as a RMS leak. Older TJs the rear oil pan would leak and be confused as a RMS leak at times.

Just clean it all off and track the leak to make sure its actually the RMS. Its an expensive job.
 
update

If for nothing else than public record heres an update on my RMS leak. Noticed it last year. First oil change of summer this year (0W-20 M1) and still leaking. Started to get a little worse in July as it got hotter (class 1 to a class 2). 2nd oil change of the summer I went with 5W-30 M1 and about 2k miles later no leak. Picture is with 2k miles on it and engine has not been degreased since the oil change. No additives or other BS. Totally dry from what I could see in the bottom of the bell housing.

Might be worth it just to bump up to 5W-30 and see if it slows down if you diagnose an RMS leak. Not trying to start an ish throwing contest here. I know there are strong opinions on oil... just relating what worked for me. I also realize that it may just be slowing things down but as much as I love wrenching on the Jeep Id rather start to have the clutch go before I rip into that area.

Cheers
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