THIS is ree-gol-durn-diculous!!!

[dpuckett]

THe rear main seal i put in just before my ill-fated venture west started leaking just before I headed back here. I dont mean a little dribble, I'm talking 300-400mi to the quart; engine oil competing with exhaust soot for spare tire coverage . The oi li s already back past the axle. AT this rate, I may as well stick a Banks kit on a 6. 9 and use less oil. I'm heading to Cummins to get the seal (the on in there now is from the parts store- O'Reilley's I think- i know mistake #1), and before I tear into this, is there anything anywhere else that may be casuing the oil leak? Kind of similar to the front timing cover gasked on the front end of the engine? I havent looked too hard in my 1990 FSM, but the index aint none too helpful.



Thanks in advance. I'm currently letting it sit since I have alternate transportation that doesnt leave an oil trail a blind man could follow.



Daniel

 

[btoscano]

How hard is it to change the rear main seal? I've got to pull the transmission so I might as well replace it. Mine weeps a little. Do I have to get standard or 1st oversize?



Thanks,

Brian

 

[btoscano]

The Cummins deal wants $38 for the rear main seal, must be a heck of a seal.



-brian

 

[Grey Wolf]

btoscano,



It's a pretty simple job once you get the trans, clutch, flywheel, etc, out of the way

 

[Jdonoghue]

Originally posted by Grey Wolf
btoscano,

It's a pretty simple job once you get the trans, clutch, flywheel, etc, out of the way

What fun, all this talk about rear main seals, how long do they usually last? I'm at 220,000+ miles now. .

 

[dpuckett]

ASK a question, and GET 3 more in reply.....

Just kidding... .

Brian-

it is just about like replacing a front main- just tap it into place, make sure you have the crank surface dry and oil free; and use the plastic doo-hickie to get the inner lip facing the right way. and yes, it is a heck of a seal- about 6" across, lot better than the piece-o-cr@p they sold me at O'Reilley's for the same price; I'm gonna get the old one out and take it in, compare the new CUmmins unit to theirs and see about a refund. If Devin is there, I'll most likely be able to get one.



The Cummins seal has a ring of rubber around the OUTER edge with about 3 ridges on it, which the off-brand seal lacks.



If yours is weeping, I'd replace it while I had it all apart. I wouldnt be redoing this one if I could go more than 1000mi on a qt of oil. If you have any doubts, put a redi-sleeve on it. Not sure of the P-N; I can check at O'Reilleys tomorrow- they got one in when I ordered the seal. Didtn have the heart to tell 'em it was 13 years, 200K mi, and several over- miled oil changes that did in the seal.



For critical stuff like this, go with genuine CUmmins parts only; it is not that much cheaper to go to the parts store, and the Cummins quality is much better.



Daniel

 

[btoscano]

Daniel,



I haven't ever seen a rear main seal on most engines before so can you tell me what the plastic doo-hickie is & how I can get the old seal out?? I take it there is some spring mechanism in this seal that holds it tight against the block and I should be happy its not an old rope seal with barbs that require dropping part of the crank



Brian

 

[Grey Wolf]

Mine was leaking about the same amount (size of a quarter) since I bought it (24,000) but it wasn't enough to mess with, for me anyway. I wanted to wait until I changed the clutch which was about 2 months ago Mine had the old style seal, like dpuckett described I got the updated version. To get it out, I drilled a small hole in the old one and put a screw in it and pulled it out.

 

[1stgen4evr]

rear seal

Dry and clean yes but oil free? I was taught to put a wipe of the same lube as the seal is to contain on new seals. Does the manual say different? If it is installed dry, it will burn before oil can lube it.



Brian, regardless of how hard it is to install the seal, do it while the transmission is out because that is the hardest part of all. There isn't an undersize for the seal. If the crank has a worn spot then use the speedy sleeve.



1stgen4evr

James

 

[cartman]

Originally posted by dpuckett

and before I tear into this, is there anything anywhere else that may be casuing the oil leak?

Daniel [/B]

check the cam plug make sure no oil is comeing from there i have seen one or two of these let go and pour oil every where good luck take care

 

[RGT]

1stgen4evr you need to install the seal dry,with dry running surface, for the new seal to break in properly

 

[boatpuller]

RGT is correct, no oil, not a drop, completely dry, use Brakleen, or other high power solvent. The seal is a nylon lip seal that needs to wear in to the crank not a standard type rubber seal.

I did mine a while back and I think it's easier to pull the aluminum mount that the seal is in and replace the seal out on the bench, then install on the crank and tighten the bolts down.



Good luck, if you're only doing the seal you can just slide your transmission back about 4-5" on the crossmember and not have to take it all the way out. You only need to disconnect the rear driveline this way(if 4X4).



Later,

Caleb

 

[Paychk]

The FSM states "CAUTION: The seal lip and the sealing surface on the crankshaft must be free from all oil residue to prevent seal leaks. "



Also it states if the seal has a rubber O. D. to lub it with soapy water and O. D. s without rubber need Loctite 277 or equivalent sealant.

 

[dpuckett]

Re: rear seal

Originally posted by 1stgen4evr

Dry and clean yes but oil free?

James-

Teflon seal, no oil this time round. No oil on front main, either, they're the same style.



Caleb-

Hadnt thought to just move the transmission back 6". I had a real devil of a time getting the cross support bolted back up last time. AND... can you pull the Al housing without removing the starter? If so, it IS easier to do on a bench.



Brian-

The plastic doo hickie is the installation pilot tool; comes in most kits, along with an installation tool. According to the FSM, it goes on the end of the crank, then put the seal on over it, drive it in via the install tool (which is the same diameter as the seal, just a buffer so you dont ding the seal itself) till the tool bottoms out, then pull out the pilot.



I looked in my FSM, and I'll have a look at the cam plug while I'm in there. May just have to be an ill-timed learning experience.



-DP

 

[BushWakr - RIP]

I believe you should be looking closely at the crank surface too. .

If there is a noticable witness mark you can seat the seal just shy of the original mark/depth and be ok. That way your new seal is running on a "new" surface.



pb. .

 

[btoscano]

Whose FSM should I be reading? The Cummins manual or the Dodge manual or both?



All I have is the Cummins maintenance manual.



So far I haven't done anything that's really required the manual but everyone says its good and I find myself asking more questions... .



Also, how much does it cost approx. and if its from the Dodge dealer is it paper and still available?



Thanks,

Brian

 

[boatpuller]

I can't remember if I had to take the starter out but I'm guessing that I did, you have to take the adapter plate off and I can't remember if you have to take the starter loose to do that or not, I can remember tightening some bolts down in that area when done. I probably just moved it a little, and left the wiring connected.

 

[Grey Wolf]

boatpuller,



I didn't remove the starter or adapter plate, the last item in the way is the flywheel after that your there



btoscano,



I usually use both manuals and the one for Dodge is available, although quite a few dollars something around $90 if memory serves me

 

[Grey Wolf]

If this works here is a photo of the old seal (left) and new style seal. The plastic installing piece is in the new seal.

 

[btoscano]

Thanks for the picture.



Brian