Rear main seal leak

Badbuzzb

Badbuzzb

Member
Joined
Sep 2, 2019
Messages
33
Location
Nanaimo,BC
Had my RMS replaced and it leaked 1500 km later.I thought the mechanic that did it just did a poor job so i went to another place and that guy said the crankshaft had a groove in it from the seal that is contributing to seal not working.I wish the first guy mentioned this.Anyway i wondering if any one else has encountered this problem.Did you just drive it or replace motor or replace crankshaft?The past owner had the bottom end rebuilt but i dont think they took the crankshaft off thus not noticing the grove.
 
Badbuzzb said:
Had my RMS replaced and it leaked 1500 km later.I thought the mechanic that did it just did a poor job so i went to another place and that guy said the crankshaft had a groove in it from the seal that is contributing to seal not working.I wish the first guy mentioned this.Anyway i wondering if any one else has encountered this problem.Did you just drive it or replace motor or replace crankshaft?The past owner had the bottom end rebuilt but i dont think they took the crankshaft off thus not noticing the grove.
Click to expand...
I’m wondering about my issue with my rear seal leaking like crazy and replaced it twice already in a year. Now I’m wondering now that I’m doing clutch if I can see something that is cause it from this angle . 🤷🏻‍♂️
 
Pcleaners2 said:
I’m wondering about my issue with my rear seal leaking like crazy and replaced it twice already in a year. Now I’m wondering now that I’m doing clutch if I can see something that is cause it from this angle . 🤷🏻‍♂️
Click to expand...
I'm not sure if the Jeep 4.0 is a candidate but certain crank shaft rear main seal surfaces can be sleeved to provide a clean smooth seal surface.
 
Pcleaners2 said:
I’m wondering about my issue with my rear seal leaking like crazy and replaced it twice already in a year. Now I’m wondering now that I’m doing clutch if I can see something that is cause it from this angle . 🤷🏻‍♂️
Click to expand...
From what I have read and Chrysler has noted is there is a hole in transmission bell housing that lets dirt in right against the rear main seal and over time causes the crankshaft to wear a groove from the seal turning on it .Once this happens you can Remove the motor and put a good used crankshaft in or just replace the motor or just tolerate the oil leaking out as long as its not bad.Also Chrysler recommended filling hole with rtv.I bought my jeep with a rebuilt motor but I know they never replaced the crankshaft so I opted to just drive and tolerate the leak for now.I did get the RMS replaced and I have wheeled it hard for about 10 hrs and so far no leak.If you have replaced your RMS and there is no groove I would chalk it up to not being done properly meaning loosening all bearing caps and rtv in the right places and retorqueing everything up right.
 
Badbuzzb said:
From what I have read and Chrysler has noted is there is a hole in transmission bell housing that lets dirt in right against the rear main seal and over time causes the crankshaft to wear a groove from the seal turning on it .Once this happens you can Remove the motor and put a good used crankshaft in or just replace the motor or just tolerate the oil leaking out as long as its not bad.Also Chrysler recommended filling hole with rtv.I bought my jeep with a rebuilt motor but I know they never replaced the crankshaft so I opted to just drive and tolerate the leak for now.I did get the RMS replaced and I have wheeled it hard for about 10 hrs and so far no leak.If you have replaced your RMS and there is no groove I would chalk it up to not being done properly meaning loosening all bearing caps and rtv in the right places and retorqueing everything up right.
Click to expand...
I used that red stuff anaerobic stuff. Maybe I should just try rtv like some others do. Maybe I’ll go that route bc I cant figure out what’s up with this thing. My tranny is coming out for a clutch . I forget if I would still need to remove oil pan (pita)
 
I used that red stuff anaerobic stuff. Maybe I should just try rtv like some others do.
Click to expand...

I would stick with the anaerobic sealer where the manual tell you to put it since the clearance is non-existant when the main is torqued up, but do use RTV type sealer on the edges of the main cap, if not oil will seep out over time.
 
I believe there are two different versions of the RMS, so make sure you have the correct part.

I believe the 4.0 is a two piece design and the smaller engine is a one piece design.

Also, I would try Pennzoil during your next oil change. My RMS had a lot of leakage with Castrol, switched to Pennzoil and leakage is basically non-existent. Could be the conditioners in the Pennzoil, but IDK, and I do know that Pennzoil basically stopped the leak.
 
I replaced one of my rig three times already within the past 5 years and still marks his territory.
He is standing his ground and making sure I acknowledge who is the boss!
 
John Scoggins said:
I would stick with the anaerobic sealer where the manual tell you to put it since the clearance is non-existant when the main is torqued up, but do use RTV type sealer on the edges of the main cap, if not oil will seep out over time.
Click to expand...
Little confused. You said to use both rtv and anaerobic ? I may end up just using rtv since the anaerobic has never worked for me. I’ll just follow the bleepin Jeep video even though he has the older two piece and I have the newer 2001 2 piece.
 
Read through the post I linked above. It has the factory installation instructions including what to use on the mating surfaces and where to put it. The anaerobic will cure without oxygen (unlike the RTV), which is why it is indicated for that part of the job.
 
  • Like
Reactions: John Scoggins and Apparition
I hear you. I knew that mine had an oil leak when I bought it late last year. I went ahead and bought all of the supplies to do the RMS, but after reading a lot of threads, I decided to retorque the valve cover and oil pan (leaks from there can look like a RMS). Doing that has drastically reduced the amount of oil I'm seeing on the ground. If you decide to try that, make sure to use the FSM to tighten in the correct order.

I plan to follow the TSB to seal the hole in the bellhousing soon.
 
My BMW's RMS leak was cured by switching from Castrol Synthetic 5-30 to Mobil conventional Super 5W-30 which has more seal conditioner additives.
 
Little confused. You said to use both rtv and anaerobic ? I may end up just using rtv since the anaerobic has never worked for me. I’ll just follow the bleepin Jeep video even though he has the older two piece and I have the newer 2001 2 piece.
Click to expand...

Yes, use both the anaerobic and RTV, see the pic below to show where the anaerobic is to be applied. For the RTV, apply is on the edges of the main cap where is meets the block, if you don't use it there the oil will have a small leak path above the oil pan gasket to escape.

1584126808318.png
 
John Scoggins said:
Yes, use both the anaerobic and RTV, see the pic below to show where the anaerobic is to be applied. For the RTV, apply is on the edges of the main cap where is meets the block, if you don't use it there the oil will have a small leak path above the oil pan gasket to escape.

View attachment 145930
Click to expand...
So rtv between the block and cap as in between them or over the corner where where they meet after they’re installed. Confused about the rtv
 
Top Bottom
Back