At wits end with rear main seal
- Thread starter hank826
- Start date
Older SBCs use a two-piece seal, too, unless you get the adapter. So you could STILL be laying under it, gnashing your teeth.
I SURE wish Chrysler would have made an adapter to a one-piece seal.
JEEPSTEVENANAIMO
TJ Enthusiast
I think we may have gotten off on the wrong foot sir and I believe I’m lashing out due to frustration over my issue so I’m sorry, I was being rude.
Let me start over, I’m fairly knowledgeable with the 4.0. this specific engine I rebuilt about 60K miles ago due to a cracked piston skirt, it was holding great for the first 50k miles but got progressively worse for the better part of a year. I’ve cleaned the rear of the engine as best as I could over the last few weeks to try and be able to pin point exactly where my leak is happening.
While running I can use an inspection mirror and verify the back of the head is dry and does not have oil running down it.
From what I can understand and see, an oil pan leak from the rear (near the RMS) and a rear main seal look almost indistinguishable from each other. That’s what I meant by not seeing the purpose of the dye, I haven’t used it before and have no experience with it so I’d love to hear how it works and your experience with it. Again I’m sorry I was being an a-hole I’m just getting tired of laying under the thing
we use it here at the dealership to figure out where the oil leaks come from rather than just taking stuff apart. use a black light to see it. much easier than trying to figure out where the oil is coming from visually with your bare eyes.
we have one model that can have a leak from a valve cover but because of how its designed it flows back to where the rear main seal would show leaking. the only way to tell is to use the dye. oil can travel very far. (i work for mercedes)
When I did mine I applied a very thin film of TV to the seal that goes into the cap. Follow instructions because you don't just coat and slap in place and tighten.
Make sure the groove/ridge or whatever you want to call it is to the front of the block.. make sure both are matching and faced properly...don't ask because I will not tell.
When you have the cap off and clean, run a cotton ball over it and sand off any burr that snags any cotton.
Make sure the groove/ridge or whatever you want to call it is to the front of the block.. make sure both are matching and faced properly...don't ask because I will not tell.
When you have the cap off and clean, run a cotton ball over it and sand off any burr that snags any cotton.
This is going to be wild but just take a seat and listen. It doesn’t leak anymore. And here’s what I did.
After wrapping the rear of the head with blue shop towels to ensure the valve cover wasn’t leaking (it was but only from the PCV grommets). I verified no oil while the engine was running, so I narrowed it down to being from either the rear main seal or the rear part of the oil pan.
I parked the jeep and left it for a few hours to cool down, while relaxing with a “cold snack” on the couch, I spoke to a buddy and he asked me what the torque spec was for the oil span bolts, I told him 7 ft lbs for the 1/4” and 11 ft lbs for the 5/16”. He said “those numbers are way below the yield strength of those bolts” although I agree with him there’s no way they should be to anywhere near yield strength, but alas, I was ready to try anything.
I tightened the rear most bolts on the oil pan, the two that hold the steel rubber overmolded strap, up to 15 ft lbs, and what do you know. The leak stopped immediately…. All the work struggle just to be fixed by 2 bolts. I rode the jeep around the block, did a couple 4,500 RPM pulls. And no evidence of leaks…
Now I’m not sure if it’s actually a permanent solution, but it worked this time, I will update this thread if it doesn’t hold in the near future, but at least I can stay hopeful now.
Now that my ordeal is over and I can stop getting a daily oil shower, does anyone have any recommendations for a cleaner/solvent to clean the underside of the tranny, the entire skid plate, and starter, it had a nice think dusty oily film that not even brake parts cleaner was getting rid of.
Thanks all for the recommendations guys.
After wrapping the rear of the head with blue shop towels to ensure the valve cover wasn’t leaking (it was but only from the PCV grommets). I verified no oil while the engine was running, so I narrowed it down to being from either the rear main seal or the rear part of the oil pan.
I parked the jeep and left it for a few hours to cool down, while relaxing with a “cold snack” on the couch, I spoke to a buddy and he asked me what the torque spec was for the oil span bolts, I told him 7 ft lbs for the 1/4” and 11 ft lbs for the 5/16”. He said “those numbers are way below the yield strength of those bolts” although I agree with him there’s no way they should be to anywhere near yield strength, but alas, I was ready to try anything.
I tightened the rear most bolts on the oil pan, the two that hold the steel rubber overmolded strap, up to 15 ft lbs, and what do you know. The leak stopped immediately…. All the work struggle just to be fixed by 2 bolts. I rode the jeep around the block, did a couple 4,500 RPM pulls. And no evidence of leaks…
Now I’m not sure if it’s actually a permanent solution, but it worked this time, I will update this thread if it doesn’t hold in the near future, but at least I can stay hopeful now.
Now that my ordeal is over and I can stop getting a daily oil shower, does anyone have any recommendations for a cleaner/solvent to clean the underside of the tranny, the entire skid plate, and starter, it had a nice think dusty oily film that not even brake parts cleaner was getting rid of.
Thanks all for the recommendations guys.
Don't clean it, you live in MI...it will help keep the rust off.
Congrats on solving your issue.
I'd take it to a self serve car wash and use their engine degreaser.
Bonus they usually recycle or filter and capture oil and contaminates.
I think I did all my oil pan bolts at 30.... that's about what my electric rachet does...but no, actually the last time I did them all by hand and feel on a gravel parking lot outside of a Napa when I beat a debt out of my oil pan and girdle.
Mine still weeps after 4 attempts. No rear drips. Just wet.
-Mac
Bonus they usually recycle or filter and capture oil and contaminates.
I think I did all my oil pan bolts at 30.... that's about what my electric rachet does...but no, actually the last time I did them all by hand and feel on a gravel parking lot outside of a Napa when I beat a debt out of my oil pan and girdle.
Mine still weeps after 4 attempts. No rear drips. Just wet.
-Mac
Great idea with engine cleaner. I forgot those existed.
Saw your location said fall creek OR, I was out there last summer when I lived in Washington picking up a Facebook marketplace find. Got an awesome picture of that covered bridge near you. Beautiful country out there.
It was near a dam on a reservoir I thought. Beautiful at night. Makes me wish I was still out that way. Sorry I don’t remember the name. Didn’t realize there was so many.
Congratulations. I’m going to do the same and tighten those two up. I hope it works!
I remember the front four go into aluminum, but it’s always a good reminder. I hope this works. I’ll probably inch up on it rather than just go full bore.
Thank you!
Just ran across this post after a quick search. Just noticed a decent sized oil puddle coming from where you’re talking about.
(New to me 2001 with 107,000 miles)
Gonna go check me some oil pan bolts!
(New to me 2001 with 107,000 miles)
Gonna go check me some oil pan bolts!
I see you have a 2post in the back there. Your time will be a lot better than mine. Hope that tightening the back 2 (or 4) works out for you as well, clean looking underside on that jeep there as well. Must be southern.
Cheers
Yeah, I’m not in a hurry but definitely want to address it. It was a Utah -Oregon - Washington rig all its life… but I still snapped a seat bolt when pulling it. Contemplating shocks when I get it back on the lift too.
Thanks!
Be careful with the upper bolts on the rear shocks, at least over here in the rust belt those tend to break off pretty easily. The nut on the frame side is welded on… break bolt off, have to lift tub off of frame a few inches, cut off old nut, weld on new nut, whole process takes a few hours if you break one of them. I’m sure there’s plenty of people recommending the best shocks for your setup in this forum. Good luck.
You should probably still swap an LS in there (KIDDING!)
Recently swapped mine in May and drove it for a 1000+ miles with no leaks but it's back to it's old slow dribble which I swear started the day after the warranty ended. I'm gonna give this a try.
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