Jeff Strickland

It's a two piece seal. It is relatively easy to replace, but seldom fails.

The actual problem is most likely the valve cover gasket. Would you like to
know how I know? I hope not.

The engine is raised on the front. Oil is pumped to the top, and flows down
the pushrods back to the crankcase to start over again. While the oil is
flowing down, it also flows to the back. The gasket likes to break in the
back. The gasket is about 1/4" thick. The hole that results when the gasket
breaks is however much the gasket shrinks wneh it breaks x 1/4" (or the
actual thickness of the gasket). Oil flows out this hole, runs down the back
of the motor and off the bottom of the bellhousing. It looks just like a
rear main. Pull the valve cover first.





"Ervin Charles" <charleserv@charter.net> wrote in message
news:tBowd.1124$dV5.44@fe03.lga...
> Hey Group,
> I've got a 91 Jeep Cherokee with a 4.0 engine. Can anyone tell me if this
> is a one piece knock-in seal or is it the old two piece type where you
> have to drop the pan and the last rear main cap. Just trying to plan my
> weekend out.
> Thanks,
> Charles
>

Jeff Strickland

It's a two piece seal. It is relatively easy to replace, but seldom fails.

The actual problem is most likely the valve cover gasket. Would you like to
know how I know? I hope not.

The engine is raised on the front. Oil is pumped to the top, and flows down
the pushrods back to the crankcase to start over again. While the oil is
flowing down, it also flows to the back. The gasket likes to break in the
back. The gasket is about 1/4" thick. The hole that results when the gasket
breaks is however much the gasket shrinks wneh it breaks x 1/4" (or the
actual thickness of the gasket). Oil flows out this hole, runs down the back
of the motor and off the bottom of the bellhousing. It looks just like a
rear main. Pull the valve cover first.





"Ervin Charles" <charleserv@charter.net> wrote in message
news:tBowd.1124$dV5.44@fe03.lga...
> Hey Group,
> I've got a 91 Jeep Cherokee with a 4.0 engine. Can anyone tell me if this
> is a one piece knock-in seal or is it the old two piece type where you
> have to drop the pan and the last rear main cap. Just trying to plan my
> weekend out.
> Thanks,
> Charles
>

Jeff Strickland

Trust us, wipe first.

If the rear main really needs to be replaced, it's easy. Well in relative
terms, it's easy. You may need to remove a motor mount and a cross member to
get the pan off. But, after you get the pan off, remove the rear bearing
journal and push the seal out of the upper journal. There is no need to pull
the trans off.




"Ervin Charles" <charleserv@charter.net> wrote in message
news:Anrwd.1176$oU7.965@fe03.lga...
>I sure wish you guys were right about the valve cover gasket, but I
>replaced it a couple of months ago. This engine has 188,000 miles on it and
>it's definitely the rear main...flowing like the Exxon Valdez. Do I
>absolutely have to pull the tranny or can I snake it in with the trans in
>place? Thanks for your replies!
> Charles
>

Jeff Strickland

Trust us, wipe first.

If the rear main really needs to be replaced, it's easy. Well in relative
terms, it's easy. You may need to remove a motor mount and a cross member to
get the pan off. But, after you get the pan off, remove the rear bearing
journal and push the seal out of the upper journal. There is no need to pull
the trans off.




"Ervin Charles" <charleserv@charter.net> wrote in message
news:Anrwd.1176$oU7.965@fe03.lga...
>I sure wish you guys were right about the valve cover gasket, but I
>replaced it a couple of months ago. This engine has 188,000 miles on it and
>it's definitely the rear main...flowing like the Exxon Valdez. Do I
>absolutely have to pull the tranny or can I snake it in with the trans in
>place? Thanks for your replies!
> Charles
>

Jeff Strickland

Trust us, wipe first.

If the rear main really needs to be replaced, it's easy. Well in relative
terms, it's easy. You may need to remove a motor mount and a cross member to
get the pan off. But, after you get the pan off, remove the rear bearing
journal and push the seal out of the upper journal. There is no need to pull
the trans off.




"Ervin Charles" <charleserv@charter.net> wrote in message
news:Anrwd.1176$oU7.965@fe03.lga...
>I sure wish you guys were right about the valve cover gasket, but I
>replaced it a couple of months ago. This engine has 188,000 miles on it and
>it's definitely the rear main...flowing like the Exxon Valdez. Do I
>absolutely have to pull the tranny or can I snake it in with the trans in
>place? Thanks for your replies!
> Charles
>

HomeBrewer

> It's a two piece seal. It is relatively easy to replace, but seldom fails.

Is the 304 the same? 2 piece?

--
_____________________
HomeBrewer
76-81-85CJ7
http://85cj7.blogspot.com/
All in one Jeep

HomeBrewer

> It's a two piece seal. It is relatively easy to replace, but seldom fails.

Is the 304 the same? 2 piece?

--
_____________________
HomeBrewer
76-81-85CJ7
http://85cj7.blogspot.com/
All in one Jeep

HomeBrewer

> It's a two piece seal. It is relatively easy to replace, but seldom fails.

Is the 304 the same? 2 piece?

--
_____________________
HomeBrewer
76-81-85CJ7
http://85cj7.blogspot.com/
All in one Jeep

Jeff Strickland

"HomeBrewer" <85cj7XXX@***.net> wrote in message
news:32f11hF3n9r4iU1@individual.net...
>> It's a two piece seal. It is relatively easy to replace, but seldom
>> fails.
>
> Is the 304 the same? 2 piece?
>


The rear main seal consists of a two-piece neoprene single lip seal. Correct
installation of the seal is required for leak-free engine operation.

Drain the oil
Remove starter motor
Remove pan
Remove pan side gaskets
Remove all sludge and throughly clean gasket surfaces
Remove rear main bearing cap
Remove and discard lower seal
Clean bearing cal throroughly
Loosen remaining bearing caps
Use brass drift and hammer to remove upper half of seal.


This is from my FSM for 1981 Jeep V8 engines. It seems to apply to both the
304 and the 360.

Jeff Strickland

"HomeBrewer" <85cj7XXX@***.net> wrote in message
news:32f11hF3n9r4iU1@individual.net...
>> It's a two piece seal. It is relatively easy to replace, but seldom
>> fails.
>
> Is the 304 the same? 2 piece?
>


The rear main seal consists of a two-piece neoprene single lip seal. Correct
installation of the seal is required for leak-free engine operation.

Drain the oil
Remove starter motor
Remove pan
Remove pan side gaskets
Remove all sludge and throughly clean gasket surfaces
Remove rear main bearing cap
Remove and discard lower seal
Clean bearing cal throroughly
Loosen remaining bearing caps
Use brass drift and hammer to remove upper half of seal.


This is from my FSM for 1981 Jeep V8 engines. It seems to apply to both the
304 and the 360.