• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Rod&Main Bearings

91xjtim

NAXJA Forum User
Yesterday I took my 91 XJ/175K to the shop to have the rear seal/oil pan gasket replaced. Was gonna charge me $270 to do it, not too bad I thought. He pulls the pan and the bearings and says that all the bearings(Rod and Main) are bad and that he highly recommends he replace them, and that they are the reason why the rear main is leaking. This fella came highly recommended and only specializes in jeeps&4x4's. But hes the first mechanic I have ever taken my XJ to.

I was at a loss for words because my oil pressure was good(20@idle and 45@2000rpm warm and 65cold it never got lower ever) However last year my wife did run it slap out of oil(Filter let loose), so boogered bearings are not out of the question I would think. My only question is I though that if they were bad your oil pressure would be crap. Any ideas? BTW Hes charging me $418 total for everything. Im a little bummed.
 
For $270.00 I'd have had that guy do my oil pan and main! took me 10-11 hrs.

$420. for all the work? Subtract the cost of parts and divide by $50-65 an hr, and I think you see that he's giving you a great deal!!
 
I think the guy's a liar.

You may (or may not) need rod bearings. It's highly unlikely that you need main bearings. More to the point, I cannot think of any way that slightly worn bearings (which still generate acceptable oil pressure) could in any way contribute to the "failure" of the rear main seal.

I put "failure" in quotes because eventually any seal will start to leak. The rear main seal on my '88 was replaced somewhere around 150k to 175k, and I considered that to be normal maintenance.
 
Eagle so you think I got taken? It didnt make sense to me when he said that if the bearings were bad that it would flip the seal out. But I am not a professional mechanic by far. Anyway, tomorrow I will see what they look like and I will take pictures and post them so yall can see and tell your thoughts. Thanx!
 
The bearings are isolated from the seal, and a rear main doesn't leak because the seal "flips out." It's captive inside the rear-most main bearing cap. It leaks because either the seal lip gets worn, or dirty oil gets in there and wears a very slight groove in the sealing surface of the crankshaft. That's why one company (FelPro?) makes a replacement seal with a double lip -- to ensure that at least one of the wiping surfaces of the seal rest on virgin surface.

I could be charitable and say maybe the guy just didn't know what he was talking about or how to explain it, but for a professional mechanic (and Jeep specialist!) to tell you that the bearings "caused" the rear main seal to leak is just plain BS IMHO.
 
Got it back today..only to find out oil filter and valve cover are also leaking. Bought oring set for oil filter(Arm coming out of block) and a napa gasket for the valve cover. Heres a couple of pictures of the bearing if anyone is interested.
95036.jpg

95037.jpg


I know the second one is a lil blurry
 
I've never had a Jeep motor apart, but for the dozens of other motors I've built, those bearings look fine for 175K. That one half that was a little galled might still run for quite some time, depending if was on top or on the bottom.

At this point though, look at it this way - you have a new rear main and new bearings, so you're good to go for quite some time now! And, if the bottom end goes now, you can get HIM to pay for it!

But, Eagle is right - blaming the bearing for the seal wearing out is simple B.S.
 
Last edited:
Just finished the oil filter adapter. Went to the dealer and got the orings for a 91. Pulled it apart(Had a 6-pt bolt holding it on, I was expecting a t60 torx, oh well it came apart easy enough) anyway got it all apart and found that those were the wrong orings...back to the dealer for the right ones. Back together and so far no leaking anywhere. This is like the first time in about 6 years it hasnt leaked..hehe.
 
Back
Top