double lipped rear main seal..does it truely exist

hey everybody

well a couple days ago i set out to do my rear main seal. went great. top seal slid in with ease, RTV, bolt it all back up, etc. went to drive the jeep, and just in the garage its pretty much pouring oil out of the rear main seal.:clap:so last night i gave it another shot. got a new seal, and really took my time insuring everything was done correctly. went to drive it today and figure theres no way its going to leak. a shop couldn't have done a better job. sure enough, new seal, everything perfect...pouring out still. now my crank does seem to have a little groove where the original lip sat, but what i dont understand is why now with new seals its 10X worse.

so with that groove im assuming that ill have to get a double lipped seal. well the felpro is advertised as being that, but its really not. BS40612 is not truely anything special, and its single even though everybody from advance to napa to online stores say its double

SO does anybody know of a seal that is really double lipped, and where i can get one.

if not, is there any way of fixing this leak short of a new crank shaft?

did you check your vavle cover gaster for leaks? just throwing it out. i just did my rear main last week. i chipped off part of my block when i did it. but mine sealede up fine. just make sure you put new pan gasket in and you seal the main cap good.

I recently discovered that the rear main wasn't leaking and instead it was the head gasket leaking oil down the back of the block into the bell housing. I replaced the head gasket and and had the head resurfaced and so far no leaks.

anybody else...i know its the rear main seal

are you sure? positive? it very well could be the oil pan?

it is only legend!!

did you use a one piece formed felpro oil pan gasket? the cork are awesome leakers
I almost messed my first rear main too, buddy noticed it was squeezing out when I tightened up the cap, glad he noticed!! mine was double lip

wishihad1 said:

anybody else...i know its the rear main seal

Click to expand...

Did you put the seal in in the right direction?

ocean_jet said:

Did you put the seal in in the right direction?

Click to expand...

this is a valid question. when i worked at the stealership, twice i saw wranglers come in with a badly leaking rear main that a customer had just replaced. two different instances where the seal had been put in facing the wrong way. it happens...

yup...knew what direction it went, and 2nd time i did it i installed it facing forward for sure. still no dice.

and im thinking that there is no double lipped seal. all of felpros are advertised as such, but they aren't.

and the oil pan gasket was a 1 piece rubber gasket

NAPA has one they claim is double lipped-

#FPGBS 40612 IIRC thats what in mine

It was pretty $$ for a seal

Wayne

Maybe they sold you the wrong Fel-Pro seal. When I did my 87 I got the double lipped seal and it had visible double lips. I had great difficulty with the rear of the oil pan sealing, and will never again do a multi-piece gasket. I thought it was the seal, but it was the pan. I gave the Jeep to my daughter, along with a case or two of oil, and she fed it oil regularly until, eventually, enough crud built up on the gasket to slow it down. By the time she sold it a year or two later, it had settled down. We found that it leaked much less if you always ran it a quart low.

Are you truly sure it's the seal? If it is, you should be able to remove the bottom flywheel cover and see the oil on the front edge of the flex disk, radiating from the center (if you have an auto - if you're manual there's no way to look).

that felpro one is double lipped. the second lip is very small on the rear of the seal. its nowhere close to the size of the main lip on the front side of the seal. i think thats the confusion.

Here is a dumb question but it scared me when I did my Grand. Are you sure it is leaking from the seal. is it possible that oil ran into the bell housing on the trans while it was apart and is coming out now that it is moving around. My grand leaked for a week after I replaced the pan because of this.

Could it be pressure in the crankcase? Might check the vent pipes on valve cover.

Clean that area REAL good and be SURE its really RMS, may be just stray leftover oil or another source. (as above noted)

Very strange problem.

Good Luck,
O

1990JEEPXJ said:

that felpro one is double lipped. the second lip is very small on the rear of the seal. its nowhere close to the size of the main lip on the front side of the seal. i think thats the confusion.

Click to expand...

I seem to recall also that the main lip also bears on a slightly different part of the shaft, to avoid the worn spot.

A thought:

Gather up any and all part numbers, mopar, napa, etc and send a e-mail to a couple (or more!) seal manufactors - tech dept. and ask them :

- What is correct seal P/N with a REAL double seal to fix a worn seal running area?

(might work!!!)

Good Luck,
O