rear main (upper installation)

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Jan 20, 2010 | 07:25 AM

4Doors

Thread Starter

Senior Member

Joined: Oct 2009

Posts: 537

Likes: 2

From: NW Florida

Year: 1999

Model: Grand Cherokee

Engine: 4.0

rear main (upper installation)

I've done a ton of searching and it seems that everyone asks how to get the thing out....but I haven't found anyone looking for advice on getting the blasted thing IN! I did one a few years ago on my old '91 and I really don't remember it being so difficult to get the new seal back in. On my current '92 however, it's been quite difficult and I ruined my first seal. I couldn't find info on any forum so I searched google and actually found this site where the guy got the following advice from 4Wheelers Supply.

Quote:

The primary reason for new rear main seals leaking is (after installation) the torn backside of the seal. Because there is a pre-load on the (upper half) seal when installed, it is all too easy to cut/tear the rubber off the back side of the seal where it meets the sharp machined edge of the back of the block (thereby creating gap and/or unequal pressure along surface).

Solution:

A thin piece of plastic (ie. the stuff used to package stuff...credit card would work, but is a little thick). Cut the plastic so that it has an ear the width of the seal journal and about 1/4 inch long. Insert the ear into backside of the journal (you are using it as you would a shoe horn to cover the sharp edge) Cover back side of seal with LIGHT coat of RTV (acts as lubricant during installation and seal when done). Seal will slide in like a greased pig on hard ice (as opposed to having to tap in with hammer). SMALL dab of RTV on mating surface (ends) of seal... DO NOT put RTV on mating surface of bearing cap; this will destroy proper bearing clearance.

It wasn't until after I messed up my first attempt that I found this advice, so I decided to practice with the bad seal (no RTV on my practice runs) and found that the above advice does very well to get the thing started, but I still could not push the seal all the way around, so I'm turning to you guys. Any more advice on how to push the seal around the crank? I think I read somewhere that you can loosen the bearing caps and allow the crank to drop ever so slightly, is this true? ANY help would be much appreciated!

Jan 20, 2010 | 07:58 AM

bsljacques

Seasoned Member

Joined: Feb 2009

Posts: 309

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From: OKC, OK

Year: 2001

Model: Cherokee

Engine: 4.0L

I am interested in this too...as I am getting ready to do this to my jeep very soon! I just got the oil filter adapter 0-rings this week and getting the Rear Main and pan seal this next week.

Jan 22, 2010 | 03:26 PM

4Doors

Thread Starter

Senior Member

Joined: Oct 2009

Posts: 537

Likes: 2

From: NW Florida

Year: 1999

Model: Grand Cherokee

Engine: 4.0

Ended up getting it in quite easily. I loosened some bearing caps, made a little "shoehorn" out of very thin plastic just as described in my original post, and the other thing that really made the difference was shooting oil in the passage with a medicine dropper. I ruined one new seal, so I kept practicing with that one over and over with no success. But when I shot oil in the hole hard enough to make it come out the other side, the seal slid in with ease. So I then got my newest new seal out of the dish of oil it had been soaking in and it slid in with almost no pressure at all. The advice given in the original post recommended using RTV on the back side to lube it, but I decided against that because I thought it might be awful if I ended having to do this again someday and there was just a tiny bit of RTV gumming the passage!