I have a 2004 Wrangler Sahara with 4L 6Cyl with a manual 5 speed. I have a ton of maintenance on it myself but figured the RMS was too big a job to jump into having to take the exhaust down. So I paid a mechanic to do it. New oil pan and gasket and RMS. Still leaking. I would argue more. Mechanic said “these are prone to leaking and will never stop”. That was him saying I am on my own. He worked for Chrysler and has been working on these for years and years and said he did it exactly correct and made sure because of its tendency to leak. I have read all the threads here on RMS. I get it they tend to leak. Do I just need to live with this or what are my options to look at? I may end up tearing into it myself.
Rear Main Seal Still Leaking
- Thread starter gziggy
- Start date
My TJ never leaked a drop of oil from any part of the engine. Last year when I was replacing my clutch & had everything apart I was looking at the RMS & thinking how this would be a great time to replace it as a preventative maintenance item, would have been really easy with the trans out. The ‘don’t fix it if it aint broke’ mentality haunted me & I passed, buttoned it all back up.
The RMS began leaking the very moment I returned from my first post-clutch install test drive and hasn’t stopped since
.
Somewhere in the universe some force or being is pissing its pants laughing at me.
Oh, as far as your question, I'd say flip a coin.
The RMS began leaking the very moment I returned from my first post-clutch install test drive and hasn’t stopped since
.Somewhere in the universe some force or being is pissing its pants laughing at me.
Oh, as far as your question, I'd say flip a coin.
Yes, they will eventually leak, but shouldn't out of the gate. I've installed several RMS and not had them leak for years. If you paid him, I'd take it back. If that isn't an option, then you'll have to tackle it yourself. People get intimidated with a RMS, but it's really not that hard. The trick is to jack up the Jeep high enough (using 6 Ton Stands) to let the axle fully drop. If it's stock suspension disconnecting the shocks helps here.
The hardest part is, as you said, getting the exhaust bolts loose. After that, the rest is relatively easy, just time consuming. The one thing you have to be very careful about is tightening the bolts on the front of the oil pan. Some of them go into the aluminum timing chain cover. You can strip these, if you're not careful. I do these by hand, with a 1/4 ratchet.
A few years ago, my Jeep had no RMS leak (but did leak coolant and transmission fluid). Always worried about preventative maintenance, I decided get it all done at the dealer. The coolant and transmission leaks were addressed but of course the RMS started leaking immediately after. It’s possible that they fudged the job but I figured it’s also possible that these things just seep to let you know things are going alright and 1/3 leaks was better than 2/3. It did improve over time and I only get a film layer of oil every few months so I have just left it alone. I would give it a few weeks to see if it improves and also use a high mileage oil before doing anything. Sometimes it just takes gravity and time to seal up.
I had mine done a few weeks ago. They said there was a slight groove in the crank from the previous seal. It still leaks but not nearly as bad. Was a pretty bad leak before. I am disappointed but it is probably as good as it will get.
I've done numerous RMS on TJ's and numerous other vehicles. I've never had one come back leaking.
Are you sure that it is the rear main seal and not the valve cover gasket leaking down the back of the block?
There is a small gap between the top of the bellhousing and the engine block, so a leak at the back of the valve cover can run down the rear of the block. giving the illusion of a RMS leak.
There is also a TSB to clean the gap and fill it with GMS to prevent dirt and debris getting in there.
Are you sure that it is the rear main seal and not the valve cover gasket leaking down the back of the block?
There is a small gap between the top of the bellhousing and the engine block, so a leak at the back of the valve cover can run down the rear of the block. giving the illusion of a RMS leak.
There is also a TSB to clean the gap and fill it with GMS to prevent dirt and debris getting in there.
I did the valve cover gasket a couple months ago myself. That is not leaking it is clean. I do not see any oil down the back of the block. This is actually leaking more than it was prior which frustrates me. The oil is actually dripping down the inside of the bell housing cover and dripping off the bottom of bell housing through that gap. It is oil not tranny fluid. There is no oil coming down the oil pan yet that I can see. I think it’s the RMS.
I am trusting that the mechanic did it correctly. But who really knows unless I do it myself. I will talk to him about it again and see if will look at it.
I've done a few RMS on the 4L. I did something to mess up the Wrangler's on the first go around and it leaked worse than the old seal. Second time I did it I had a small drop occasionally. I stepped up to 5W-40 oil and I haven't seen oil since. For the newer ones make sure to use just a dab of anaerobic sealant on the bearing caps. I got messy the first time and I think that caused issues.
Make sure you valve cover gasket is in good shape as well.
Make sure you valve cover gasket is in good shape as well.
I ended up doing my rear main twice and the pan 4 times in a few months to get it right. The first rear main I accidently cut the back of the seal when I was walking it into the block. It leaked. The pan gaskets can be a pain as well. They have a tendency to fold or fall off the back of the pan where it pinches between the pan and the rear bearing cap. It can be tricky to keep the gasket in the rear bearing cap groove. Also I thought mine was still leaking, but it turned out the bell housing on the trans had a small pool of oil in it that would come out when driving. I drilled a small hole at the lowest point of the bell housing right behind the clutch and it all drained out. Now it hasn't dripped a drop in almost a month.
Let me guess you're running a synthetic engine oil. If you are, that commonly causes the RMS to start shrinking/shriveling due to a lack of seal enhancers in many of them. Try this, which normally works to restore the RMS and stop leaks. It sealed my BMW's big RMS leak within a week. Simply change the engine oil to a conventional High Mileage 10W-30, my bet is the leak will be gone within a week of driving. The High Mileage version of a conventional engine oil has additional amounts of seal restoring products that can help insure the seal does its job.
The top part of the two-piece RMS can be tricky to slide around the crank without tearing. Even the smallest sliver could cause issues.
I just replaced mine and I ended up skinning it slightly so I opted to head to the parts store for another.
Also, my oil pan seal right below the RMS got pinched at install and caused a leak that I thought was the RMS again. Just an idea of something else that could've gone wrong.
Before I dived into it again or went back to the guy that replaced it, I would check the areas above the RMS really well to make sure it's not another issue like the valve cover gasket or a PCV grommet. My rear PCV grommet was leaking and dripped down the backside of the valve cover, just FYI.
If you rule out everything else and opt to do the RMS, using anaerobic sealant at the required areas on the bearing cap and installing the top seal piece without damaging is very important.
I just replaced mine and I ended up skinning it slightly so I opted to head to the parts store for another.
Also, my oil pan seal right below the RMS got pinched at install and caused a leak that I thought was the RMS again. Just an idea of something else that could've gone wrong.
Before I dived into it again or went back to the guy that replaced it, I would check the areas above the RMS really well to make sure it's not another issue like the valve cover gasket or a PCV grommet. My rear PCV grommet was leaking and dripped down the backside of the valve cover, just FYI.
If you rule out everything else and opt to do the RMS, using anaerobic sealant at the required areas on the bearing cap and installing the top seal piece without damaging is very important.
No synthetic. But after I get this fixed I am going to heavier oil for sure.
I am going to look over everything really good and take it back to the mechanic to look at again. It should not be leaking. If he won’t do the right thing or he can’t fix it I will do it myself. And do it right.
Before going to a higher than recommended viscosity I'd try a High Mileage version.
Changed mine 3 times in a span of 3 days, could not stop the leak. Kind or type of oil has no effect on it.
I look at it from the perspective of "how much" it leaks instead of "if it leaks".
Mine leaves a wet surface on dust shield, it does not pool or form drops, and skid plate is not stained with oil. That is thumbs up in my book.
It is not a complex job, more of inconvenient and pita.
Have at it if your heart desires, but id say to accept it as is as long as you not seeing oil drops forming.
I look at it from the perspective of "how much" it leaks instead of "if it leaks".
Mine leaves a wet surface on dust shield, it does not pool or form drops, and skid plate is not stained with oil. That is thumbs up in my book.
It is not a complex job, more of inconvenient and pita.
Have at it if your heart desires, but id say to accept it as is as long as you not seeing oil drops forming.
