Repair Rear main seal or not?

[zvm77us]

I got a 1999 cherokee xj with only 60,000 miles on it which I love. Problem is that it has a leak by the rear main seal, it leaks on the driveway the size of a quarter if i drive it and leave it over night. I see no effect on the oil dip stick. Besides the environment should i get it fixed or just keep an eye on it and let it be.
I know how to do the job just from what I understand its a PITA (although cheap enough on parts since its a 2 piece gasket). But I really don't want to repair if I don't have to.
In case your wondering I use castrol gtx 10w30 . Thanks in advance.

 

[dave1251]

You can try a HM oil to see if this helps to slow down the leak. But I am a fan if you have the money or the skill to fix it. You never know once you replace your rear main you may find out something else that is wrong. This could help you save serious cash in the long run.

 

[mongo161]

IMO...switch to a High Mileage motor oil and see if that cures the leak.

You can stay with Castrol HM or try Valvoline, Mobil, Pennzoil, Quaker State or even WalMart High Mileage motor oil. What ever is the least amount of money.

IMO...The seal conditioners in the HM motor oils might solve the leak by swelling up the seals after a couple or three OCI's. I would stick with the HM oils to give you peace of mind.

 

[zvm77us]

Can a high mileage oil do any damage (like over swell a seal and cause a burst)? Just asking since I have never used a hi mileage oil

 

[Chris142]

Check your oil pan bolts. I've Fixed a few jeeps that were thought to be a rear main just by tightning the pan bolts.

 

[zvm77us]

Originally Posted By: Chris142
Check your oil pan bolts. I've Fixed a few jeeps that were thought to be a rear main just by tightning the pan bolts.


I see the oil trace leading all the way up to the rear main seal

 

[crazyoildude]

use a high mileage oil 10w30 and see what happens i have seen high mileage oil stop leaks before. hm oil will not do any damage by over swelling seals
i use it in 2 of my high mileage engines

 

[earlyre]

i know what i am about to say is completely unrelated, but i can tell you in the late 60's my parents made it back to college (from Lima, Ohio to McPherson, Kansas) with a blown rear main seal. just had to stop @ nearly every gas station and fill 'er up w/ oil...
no idea what car it was.. it was a good 15 or so years before I was born, just heard the story a few times.(any time some one has had to have the rear main replaced on a car.)

 

[MNgopher]

Before you condemn the rear main seal, make sure that it isn't leakage from either the oil filter adapter O-rings or the valve cover. On my '88 XJ, a rear main seal leak was suspected, but was the valve cover leaking, and again later was the O-rings. All of these issues are common, including the rear main seal, but check the easier ones first.

After that, so long as the leakage is manageable and you can live with your Jeep marking its territory, then it can wait until you feel like adressing it.

 

[GMBoy]

Originally Posted By: MNgopher
Before you condemn the rear main seal, make sure that it isn't leakage from either the oil filter adapter O-rings or the valve cover. On my '88 XJ, a rear main seal leak was suspected, but was the valve cover leaking, and again later was the O-rings. All of these issues are common, including the rear main seal, but check the easier ones first.

After that, so long as the leakage is manageable and you can live with your Jeep marking its territory, then it can wait until you feel like adressing it.


CORRECT! These trucks will all leak oil from one of these places at one (or more) points in their lives. My 2000 Cherokee Limited (I wish I never sold) leaked at the oil filter adapter and rear main. 10 mins to fix the oil adapter seal and under 2 hrs (taking my time) for the rear main. Very easy job overall. You can wait, and try the HM oil. Eventually you won't want to smell the burning oil anymore, lol.

 

[mechtech2]

GM -
2 hours to replace a rear main? And taking your time?

 

[GMBoy]

Originally Posted By: mechtech2
GM -
2 hours to replace a rear main? And taking your time?


Lol. Yes. Jacking it up and removing the oil pan took the longest time. Once the pan is off and you remove the long brace protecting the bearings and remove the rear most bearing cap, the seal itself is a 5min job. I used the newer style 1 piece oil pan gasket when I did my 2000 4.0 Cherokee as well as the older 4.2 CJ7. I also did the transmission fluid while I was under there.

 

[Dakota1820]

I've seen rislone rear main seal repair work pretty good. Though I agree check the oil pan and oil filter adapter seal first . I'd clen it very good then park it overnight and see what it does.

 

[Vikas]

If you have decided to replace the seal, why not try for a miracle in a bottle first? ATP chemicals seems to have potential. If it fixes it, great. If not, you are out for $10.

- Vikas

 

[zvm77us]

I am cautious about using mirical in a bottle type chemicals, on my impala I used lucas for a power stearing leak all it did was blow a line (As well as on my friends mitsubishi where it made a leak worse) I also used bars rack and pinion seal on the impala at a lter time it did stop the leak but it made the steering so hard that I had to get it out of the system with a turkey baster

 

[ltslimjim]

Use a 10w-30 HM oil. I prefer MaxLife, but any will do. That's just from my experience. Give it a year, or at least 2 oil changes worth to see if the leak quiets down. Sometimes, one HM formula will respond better in one app compared to another so you may have to try a couple of HM oils.