RMS Leaking, advice needed, 2nd time in a month

Jeep05tj

New Member
Joined
Jan 4, 2022
Messages
22
Location
Geelong, Australia
Hey everyone,

Since owning my 2005 Wrangler 4.0 manual (8 months), I've had a leak from the RMS. It was a really slow drip with maybe one drop every 3-4 days. In mid July, I had the cats off as I was doing the exhaust manifold gasket and decided to the RMS straight after. Once I got the pan off, I was amazed to see what I believe was the original oil pan gasket. It was rock hard and really frail, peeling off with ease. The RMS appeared to be a mopar one and had compressed along the lip.

I did my best to do it by the book. I had a felpro oil pan gasket and RMS ready to go. Once I thoroughly cleaned the RMS bearing cap and all surfaces, I applied anaerobic sealant and a light dab of RTV to the ends of the RMS. I also set a slight offset too.

I continued on and re-assembled everything and made sure everything was torqued to spec. Once it was complete, I let it sit with no oil for a couple of days to make sure the gasket sealants had set. I then filled it with oil and started it up and no leaks. The next morning, no leaks. I then went on a 3 day camp which probably equated to 500miles worth of driving. Once I returned home after about 6 hours of highway driving, it was dripping hard out of the RMS area all over the driveway. It ended up leaving a little puddle about the size of a small dinner plate.

Tonight I got the oil pan off to inspect the oil pan gasket, which was a PITA because of the RTV in the leak prone areas. The gasket split when I took it off around the bearing cap area.

It's hard to tell if it was leaking past the oil pan or the RMS, but I have a few questions for the next RMS install tomorrow.

-How do you clean the top area where the top half of the RMS goes?
-Is it possible I didn't seat the oil pan gasket properly around the bearing cap? In which the RTV held it together initally but gave way on my way home?
-Does anyone have anything to add in regards to what I've done wrong or missed?
-Can anyone confirm if Mopar oil pan gasket's have the extra notch? Photo attached of my old oil pan gasket vs the new felpro.
-When I took the bearing cap off today, there was no residue from the anaerobic sealant. Is that normal? Or did I not put enough on? (Photo attached of when I first put it in).

Any help would be greatly appreciated, cheers.

q3.jpg


q4.jpg


q1.jpg


q5.jpg
 
Although not uncommon to offset them - I don't.

I do add anaerobic sealer to the mating faces of the rear main seal trying not to get too much on the actual lip of the seal.

And although they can leak in reasonably short time if they are leaking immediately you have to ask yourself if you have I either torn it or just not got enough crush on the mating faces which could be either you to the offset or simply due to not using sealer on the mating faces.


In terms of cleaning, I use brake cleaner inside the upper area and then compressed air.
 
Although not uncommon to offset them - I don't.

I do add anaerobic sealer to the mating faces of the rear main seal trying not to get too much on the actual lip of the seal.

And although they can leak in reasonably short time if they are leaking immediately you have to ask yourself if you have I either torn it or just not got enough crush on the mating faces which could be either you to the offset or simply due to not using sealer on the mating faces.


In terms of cleaning, I use brake cleaner inside the upper area and then compressed air.

Thanks Captainbanana.
How long to you typically get out of your RMS before it leaks?
 
I've read my fair share of RMS threads, what is this offset you speak of?


And is this the process you followed? (Locktite 518 is the anaerobic sealant)


1659707522305.png
 
  • Like
Reactions: RMETeeJay
For those with RMS leaks, some synthetic engine oils are far more prone to leaching the products out of the RMS seals that help them to seal effectively. Once an engine gets enough miles on it it's always a good idea to switch to a High Mileage engine oil that has restorative products in them to help keep the seals in good condition. A BMW I had developed a major RMS leak, I was adding a quart of oil every couple days. Stymied by the nearly $2k cost of having the RMS replaced I scoured the BMW forums, all suggested going to a conventional High Mileage engine oil. I did that and damned if my RMS leak wasn't completely cured of its RMS leak in about a week of daily driving.

I normally drive nothing but conventional engine oils since where I live it was temperate and didn't need the qualities synthetics have in ultra-cold conditions. Never an engine problem in well over 50 years of driving on nearly nothing but conventional engine oils. Only that BMW ever got synthetic engine oil and only because it nagged on me with its 'Use Castrol Synthetic' on its oil cap lol. It ran just as well after its switch to Mobil conventional High Mileage.
 
  • Like
Reactions: TheBoogieman
Thanks Captainbanana.
How long to you typically get out of your RMS before it leaks?

This is my first time doing one on a 4.0 so I have no idea how long mine will go.

If you have a massive leak you could have installed it backwards or nicked it. Is the leak now worse than the original leak? How's your blow by?
 
For those with RMS leaks, some synthetic engine oils are far more prone to leaching the products out of the RMS seals that help them to seal effectively. Once an engine gets enough miles on it it's always a good idea to switch to a High Mileage engine oil that has restorative products in them to help keep the seals in good condition.

Why would a brand new RMS leak with synthetic due to the milage of the engine?
 
-Is it possible I didn't seat the oil pan gasket properly around the bearing cap? In which the RTV held it together initally but gave way on my way home?

Yes. If it was sticking out toward the rear.

-Does anyone have anything to add in regards to what I've done wrong or missed?

I'm going through similar turmoil (thanks @Apparition for reminding me). Use Mopar RMS and RTV.

-Can anyone confirm if Mopar oil pan gasket's have the extra notch? Photo attached of my old oil pan gasket vs the new felpro.

I don't think it does.

-When I took the bearing cap off today, there was no residue from the anaerobic sealant. Is that normal? Or did I not put enough on? (Photo attached of when I first put it in).

Based on my very limited experience and observations, this should not be the case. I think it washed out.
 
Thanks for the responses everyone. Just to note, I did use conventional oil and a fram oil filter.

I think when I install it today, I won't do the offset. I imagine that's what cause the anaerobic sealant to be washed out, the fact that may not have had the ends of the RMS flush.

I also don't think I cleaned the top half of the RMS cavity enough, so I'll give use some brake cleaner and a compressor as suggested.

I'll hopefully post some positive results soon.
 
Yesterday i successfully replaced my RMS.
After the first 3 or 4 failed attempts i did noticed people mentioning to do seal offset, and as much as i ran that scenario in my head i could not see how that could be done successfully. Yesterday i was tinkering with that idea while laying under the engine, with everything before my eyes and i still came to the same conclusion. I dont know how tight everyone elses tolerances are in there, mine are tight enough to force me take my sweet time, otherwise sharp edges start cutting chunks out of the seal. And then try to force lower half in there while pushing or pulling upper half at the same time?
Now, lets take it one step further, lets say you successfully offset it without any damage to the seals, how are you sealing up the gaps between two seals?


-How do you clean the top area where the top half of the RMS goes?
-Is it possible I didn't seat the oil pan gasket properly around the bearing cap? In which the RTV held it together initally but gave way on my way home?
-Does anyone have anything to add in regards to what I've done wrong or missed?
-Can anyone confirm if Mopar oil pan gasket's have the extra notch? Photo attached of my old oil pan gasket vs the new felpro.
-When I took the bearing cap off today, there was no residue from the anaerobic sealant. Is that normal? Or did I not put enough on? (Photo attached of when I first put it in).

1. Paper towel and brake cleaner. My main concern is oil free surface, any leftovers from anaerobic sealer is no big deal.
2. The way i see it when you tighten the oil pan, gasket will shift in its proper place or away from it. I dont see how it can be somewhere in between, or work one moment and not work few moments later. If it was badly seated, you would have seen the results of it shortly after (unless you did not check for 500 miles)
3. Try to apply more sealant.
It looks like you went with factory instructions, i did so as well my first 3 failed attempts. This time i used more sealant and everything worked out.
Screenshot_20220801-181818~2.png
Note how there is enought sealant to fill into all the gaps between seal and bearing cap, as well as 2 cuts between upper and lower half.

4. I can only confirm no issues with FelPro oil pan gaskets, 4 or 5 times i used them after redoing RMS.
5. Anaerobic leaves a very thin layer when it dries. If you apply as much as in picture above, you would notice it due to a slight discoloration, it is still a very thin layer thought. If you take a blade to it you will see that there is not much of it.
 
  • Like
Reactions: Jeep 541X
@eastbloc Thank you for the picture. I will have to tackle this job soon and was unsure of the best way to apply the sealant. What RMS gasket did you use also? Mopar or Felpro

Two years ago i was on here asking for clarification on sealant application because after going through factory manual and different guides, i was left with more questions and uncertainty than i should have been for a job like this.

Initially i used FelPro, this time i used Mopar.
I highly doubt that using this or that will directly correlate with success or not. With them side by side, to my eye they are identical, there was nothing that stood out between them two that would make make me think one is clearly a better option. Old seal did not offer any explanation, there was no tear or wear, no deformation, both lips applying pressure to the surface...

Since you are asking, it is probably better to go with Mopar only because if it leaks again you will be kicking yourself for going with FelPro.
 
For those with RMS leaks, some synthetic engine oils are far more prone to leaching the products out of the RMS seals that help them to seal effectively. Once an engine gets enough miles on it it's always a good idea to switch to a High Mileage engine oil that has restorative products in them to help keep the seals in good condition. A BMW I had developed a major RMS leak, I was adding a quart of oil every couple days. Stymied by the nearly $2k cost of having the RMS replaced I scoured the BMW forums, all suggested going to a conventional High Mileage engine oil. I did that and damned if my RMS leak wasn't completely cured of its RMS leak in about a week of daily driving.

I normally drive nothing but conventional engine oils since where I live it was temperate and didn't need the qualities synthetics have in ultra-cold conditions. Never an engine problem in well over 50 years of driving on nearly nothing but conventional engine oils. Only that BMW ever got synthetic engine oil and only because it nagged on me with its 'Use Castrol Synthetic' on its oil cap lol. It ran just as well after its switch to Mobil conventional High Mileage.

Conventional high mileage oil worked on my 2.5. Took a few hundred miles but it’s not leaking a drop since my last oil change a few days back. I had read your post about 3000 miles ago and figured what the hell I’ll give it a shot. So thank you Mr. Bransford
 
  • Like
Reactions: Jerry Bransford
I followed the same advice and switched from Synthetic to Napa's High Mileage oil however, the oil leak did not go away, although, it did get much lighter. I will be attempting RMS R/R in the next week or two. Thanks, @eastbloc for the info above.