Rear main seal
Elder User
Joined: Oct 2002
Posts: 513
Likes: 0
From: Lincoln NE
I believe that that is a one piece seal. Not a real fun job. You have to remove the transmission to get to it if it is indeed one piece. If you have the engine hoist and stand, I've heard that it is easier to remove the motor. I have a 351w and did mine last summer and it is something that I decided that I'd take to a mechanic if it ever needs to be done again cause it's hard to do yourself without the proper tools.
More Turbo
Joined: Mar 2002
Posts: 508
Likes: 2
From: Easthampton, Ma.
That could be either a one piece or two piece seal judging from the year.
These motors also are known for having bad lower end bearings (knocking upon start-up and low oil pressure)
The best way to do this job is to remove the motor from the truck, install it on an engine stand, remove the oil pan and change the rod and main bearings along with the rear seal.
No need to remove the crank for machining unless it is damaged! Just take your old bearings for replacement match-up.
Remember, we are not rebuilding the motor, just extending it's longevity.
Not a difficult job and you will have peace of mind afterwards knowing that you covered all bases while you were in there.
Good luck!
Steve G.
These motors also are known for having bad lower end bearings (knocking upon start-up and low oil pressure)
The best way to do this job is to remove the motor from the truck, install it on an engine stand, remove the oil pan and change the rod and main bearings along with the rear seal.
No need to remove the crank for machining unless it is damaged! Just take your old bearings for replacement match-up.
Remember, we are not rebuilding the motor, just extending it's longevity.
Not a difficult job and you will have peace of mind afterwards knowing that you covered all bases while you were in there.
Good luck!
Steve G.
Senior User
Joined: Jan 2002
Posts: 377
Likes: 0
if her eis no knocking no point in doing a bearing job, i just replced my 1 piece on a 85 4.9. went to my uncles shop, put it on the lift, removed the tranny and t-case using a cherry picker with a mounting on top of it designed to do this, the pulled the seal out. tapped the new one and bolted it up..
