My '94 YJ has been a chronic leaker at the main seal ever since it was new.
The original owner had the main seal replaced at 10 & 20k miles, then traded
it off at 25k. I had it replaced at 28k, along with a new clutch to replace
the oil-soaked, chattering original. That seal made it maybe 7k before it
started to drip, I finally had had enough and replaced it again at around
45k. By 52k it was dripping again, which I ignored until 63k, at which time
I replaced it yet again. Frankly, the one I pulled out looked as good as the
new one I put in. The new one didn't waste any time dripping, it immediately
leaked as bad as the one I took out. ENOUGH!

Ok, this much we know: The pan gasket isn't leaking, dry all around. Neither
is the valve cover gasket, it's as dry as a bone at the back of the cyl head
and all around as well. The thing drips from behind the separator plate
between the eng and trans, and it is motor oil, not gear lube that's
leaking.

When I pulled the lower rear bearing half it showed signs of seepage behind
the seal. When I put the new one back in the upper slid in very easily, and
the lower half fit perfectly. The sealing surface on the crank is fine. I
sealed the bearing cap mating surface edges with high temp RTV per the
manual. All went together easily, torqued up fine, etc.

The only idea I have left is that the pressed in oil galley plug at the back
of the block may be seeping, but to know for sure I'd have to pull the
trans. Otherwise, I'm out of ideas. HELP!!!!

 

I can't think of a way to do this on an engine that is assembled, but when I
put an engine together I normally put a small bead of RTV in the groove of
the seal that mates with the "rib" on the main cap and the block. As soon as
the cap is installed, I turn the crank a few revolutions to let the seal
center itself (not sure if it is necessary or not, but I do it). This will
prevent the seepage from behind the seal. If its not coming from there,
then, like you said, you probably have an oil plug leaking, but if you
change the seal and it stops for a while, It would make sense that it is the
seal.

Chris

"Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
news:c98r540s1l@enews3.newsguy.com...
> My '94 YJ has been a chronic leaker at the main seal ever since it was
new.
> The original owner had the main seal replaced at 10 & 20k miles, then
traded
> it off at 25k. I had it replaced at 28k, along with a new clutch to
replace
> the oil-soaked, chattering original. That seal made it maybe 7k before it
> started to drip, I finally had had enough and replaced it again at around
> 45k. By 52k it was dripping again, which I ignored until 63k, at which
time
> I replaced it yet again. Frankly, the one I pulled out looked as good as
the
> new one I put in. The new one didn't waste any time dripping, it
immediately
> leaked as bad as the one I took out. ENOUGH!
>
> Ok, this much we know: The pan gasket isn't leaking, dry all around.
Neither
> is the valve cover gasket, it's as dry as a bone at the back of the cyl
head
> and all around as well. The thing drips from behind the separator plate
> between the eng and trans, and it is motor oil, not gear lube that's
> leaking.
>
> When I pulled the lower rear bearing half it showed signs of seepage
behind
> the seal. When I put the new one back in the upper slid in very easily,
and
> the lower half fit perfectly. The sealing surface on the crank is fine. I
> sealed the bearing cap mating surface edges with high temp RTV per the
> manual. All went together easily, torqued up fine, etc.
>
> The only idea I have left is that the pressed in oil galley plug at the
back
> of the block may be seeping, but to know for sure I'd have to pull the
> trans. Otherwise, I'm out of ideas. HELP!!!!
>
>

 

I can't think of a way to do this on an engine that is assembled, but when I
put an engine together I normally put a small bead of RTV in the groove of
the seal that mates with the "rib" on the main cap and the block. As soon as
the cap is installed, I turn the crank a few revolutions to let the seal
center itself (not sure if it is necessary or not, but I do it). This will
prevent the seepage from behind the seal. If its not coming from there,
then, like you said, you probably have an oil plug leaking, but if you
change the seal and it stops for a while, It would make sense that it is the
seal.

Chris

"Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
news:c98r540s1l@enews3.newsguy.com...
> My '94 YJ has been a chronic leaker at the main seal ever since it was
new.
> The original owner had the main seal replaced at 10 & 20k miles, then
traded
> it off at 25k. I had it replaced at 28k, along with a new clutch to
replace
> the oil-soaked, chattering original. That seal made it maybe 7k before it
> started to drip, I finally had had enough and replaced it again at around
> 45k. By 52k it was dripping again, which I ignored until 63k, at which
time
> I replaced it yet again. Frankly, the one I pulled out looked as good as
the
> new one I put in. The new one didn't waste any time dripping, it
immediately
> leaked as bad as the one I took out. ENOUGH!
>
> Ok, this much we know: The pan gasket isn't leaking, dry all around.
Neither
> is the valve cover gasket, it's as dry as a bone at the back of the cyl
head
> and all around as well. The thing drips from behind the separator plate
> between the eng and trans, and it is motor oil, not gear lube that's
> leaking.
>
> When I pulled the lower rear bearing half it showed signs of seepage
behind
> the seal. When I put the new one back in the upper slid in very easily,
and
> the lower half fit perfectly. The sealing surface on the crank is fine. I
> sealed the bearing cap mating surface edges with high temp RTV per the
> manual. All went together easily, torqued up fine, etc.
>
> The only idea I have left is that the pressed in oil galley plug at the
back
> of the block may be seeping, but to know for sure I'd have to pull the
> trans. Otherwise, I'm out of ideas. HELP!!!!
>
>

 

I can't think of a way to do this on an engine that is assembled, but when I
put an engine together I normally put a small bead of RTV in the groove of
the seal that mates with the "rib" on the main cap and the block. As soon as
the cap is installed, I turn the crank a few revolutions to let the seal
center itself (not sure if it is necessary or not, but I do it). This will
prevent the seepage from behind the seal. If its not coming from there,
then, like you said, you probably have an oil plug leaking, but if you
change the seal and it stops for a while, It would make sense that it is the
seal.

Chris

"Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
news:c98r540s1l@enews3.newsguy.com...
> My '94 YJ has been a chronic leaker at the main seal ever since it was
new.
> The original owner had the main seal replaced at 10 & 20k miles, then
traded
> it off at 25k. I had it replaced at 28k, along with a new clutch to
replace
> the oil-soaked, chattering original. That seal made it maybe 7k before it
> started to drip, I finally had had enough and replaced it again at around
> 45k. By 52k it was dripping again, which I ignored until 63k, at which
time
> I replaced it yet again. Frankly, the one I pulled out looked as good as
the
> new one I put in. The new one didn't waste any time dripping, it
immediately
> leaked as bad as the one I took out. ENOUGH!
>
> Ok, this much we know: The pan gasket isn't leaking, dry all around.
Neither
> is the valve cover gasket, it's as dry as a bone at the back of the cyl
head
> and all around as well. The thing drips from behind the separator plate
> between the eng and trans, and it is motor oil, not gear lube that's
> leaking.
>
> When I pulled the lower rear bearing half it showed signs of seepage
behind
> the seal. When I put the new one back in the upper slid in very easily,
and
> the lower half fit perfectly. The sealing surface on the crank is fine. I
> sealed the bearing cap mating surface edges with high temp RTV per the
> manual. All went together easily, torqued up fine, etc.
>
> The only idea I have left is that the pressed in oil galley plug at the
back
> of the block may be seeping, but to know for sure I'd have to pull the
> trans. Otherwise, I'm out of ideas. HELP!!!!
>
>

 

I can't think of a way to do this on an engine that is assembled, but when I
put an engine together I normally put a small bead of RTV in the groove of
the seal that mates with the "rib" on the main cap and the block. As soon as
the cap is installed, I turn the crank a few revolutions to let the seal
center itself (not sure if it is necessary or not, but I do it). This will
prevent the seepage from behind the seal. If its not coming from there,
then, like you said, you probably have an oil plug leaking, but if you
change the seal and it stops for a while, It would make sense that it is the
seal.

Chris

"Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
news:c98r540s1l@enews3.newsguy.com...
> My '94 YJ has been a chronic leaker at the main seal ever since it was
new.
> The original owner had the main seal replaced at 10 & 20k miles, then
traded
> it off at 25k. I had it replaced at 28k, along with a new clutch to
replace
> the oil-soaked, chattering original. That seal made it maybe 7k before it
> started to drip, I finally had had enough and replaced it again at around
> 45k. By 52k it was dripping again, which I ignored until 63k, at which
time
> I replaced it yet again. Frankly, the one I pulled out looked as good as
the
> new one I put in. The new one didn't waste any time dripping, it
immediately
> leaked as bad as the one I took out. ENOUGH!
>
> Ok, this much we know: The pan gasket isn't leaking, dry all around.
Neither
> is the valve cover gasket, it's as dry as a bone at the back of the cyl
head
> and all around as well. The thing drips from behind the separator plate
> between the eng and trans, and it is motor oil, not gear lube that's
> leaking.
>
> When I pulled the lower rear bearing half it showed signs of seepage
behind
> the seal. When I put the new one back in the upper slid in very easily,
and
> the lower half fit perfectly. The sealing surface on the crank is fine. I
> sealed the bearing cap mating surface edges with high temp RTV per the
> manual. All went together easily, torqued up fine, etc.
>
> The only idea I have left is that the pressed in oil galley plug at the
back
> of the block may be seeping, but to know for sure I'd have to pull the
> trans. Otherwise, I'm out of ideas. HELP!!!!
>
>

 

"c" <c@me.org> wrote in message
news:IVStc.26664$zn.11604@twister.rdc-kc.rr.com...
> I can't think of a way to do this on an engine that is assembled, but when
I
> put an engine together I normally put a small bead of RTV in the groove of
> the seal that mates with the "rib" on the main cap and the block. As soon
as
> the cap is installed, I turn the crank a few revolutions to let the seal
> center itself (not sure if it is necessary or not, but I do it). This will
> prevent the seepage from behind the seal. If its not coming from there,
> then, like you said, you probably have an oil plug leaking, but if you
> change the seal and it stops for a while, It would make sense that it is
the
> seal.

Well, it used to stop for a3while, but now the %$#^er just kept on leakin'.
I suppose the only way to know for sure what's really going on is to pull
the trans.

>
> Chris
>
> "Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
> news:c98r540s1l@enews3.newsguy.com...
> > My '94 YJ has been a chronic leaker at the main seal ever since it was
> new.
> > The original owner had the main seal replaced at 10 & 20k miles, then
> traded
> > it off at 25k. I had it replaced at 28k, along with a new clutch to
> replace
> > the oil-soaked, chattering original. That seal made it maybe 7k before
it
> > started to drip, I finally had had enough and replaced it again at
around
> > 45k. By 52k it was dripping again, which I ignored until 63k, at which
> time
> > I replaced it yet again. Frankly, the one I pulled out looked as good as
> the
> > new one I put in. The new one didn't waste any time dripping, it
> immediately
> > leaked as bad as the one I took out. ENOUGH!
> >
> > Ok, this much we know: The pan gasket isn't leaking, dry all around.
> Neither
> > is the valve cover gasket, it's as dry as a bone at the back of the cyl
> head
> > and all around as well. The thing drips from behind the separator plate
> > between the eng and trans, and it is motor oil, not gear lube that's
> > leaking.
> >
> > When I pulled the lower rear bearing half it showed signs of seepage
> behind
> > the seal. When I put the new one back in the upper slid in very easily,
> and
> > the lower half fit perfectly. The sealing surface on the crank is fine.
I
> > sealed the bearing cap mating surface edges with high temp RTV per the
> > manual. All went together easily, torqued up fine, etc.
> >
> > The only idea I have left is that the pressed in oil galley plug at the
> back
> > of the block may be seeping, but to know for sure I'd have to pull the
> > trans. Otherwise, I'm out of ideas. HELP!!!!
> >
> >
>
>

 

"c" <c@me.org> wrote in message
news:IVStc.26664$zn.11604@twister.rdc-kc.rr.com...
> I can't think of a way to do this on an engine that is assembled, but when
I
> put an engine together I normally put a small bead of RTV in the groove of
> the seal that mates with the "rib" on the main cap and the block. As soon
as
> the cap is installed, I turn the crank a few revolutions to let the seal
> center itself (not sure if it is necessary or not, but I do it). This will
> prevent the seepage from behind the seal. If its not coming from there,
> then, like you said, you probably have an oil plug leaking, but if you
> change the seal and it stops for a while, It would make sense that it is
the
> seal.

Well, it used to stop for a3while, but now the %$#^er just kept on leakin'.
I suppose the only way to know for sure what's really going on is to pull
the trans.

>
> Chris
>
> "Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
> news:c98r540s1l@enews3.newsguy.com...
> > My '94 YJ has been a chronic leaker at the main seal ever since it was
> new.
> > The original owner had the main seal replaced at 10 & 20k miles, then
> traded
> > it off at 25k. I had it replaced at 28k, along with a new clutch to
> replace
> > the oil-soaked, chattering original. That seal made it maybe 7k before
it
> > started to drip, I finally had had enough and replaced it again at
around
> > 45k. By 52k it was dripping again, which I ignored until 63k, at which
> time
> > I replaced it yet again. Frankly, the one I pulled out looked as good as
> the
> > new one I put in. The new one didn't waste any time dripping, it
> immediately
> > leaked as bad as the one I took out. ENOUGH!
> >
> > Ok, this much we know: The pan gasket isn't leaking, dry all around.
> Neither
> > is the valve cover gasket, it's as dry as a bone at the back of the cyl
> head
> > and all around as well. The thing drips from behind the separator plate
> > between the eng and trans, and it is motor oil, not gear lube that's
> > leaking.
> >
> > When I pulled the lower rear bearing half it showed signs of seepage
> behind
> > the seal. When I put the new one back in the upper slid in very easily,
> and
> > the lower half fit perfectly. The sealing surface on the crank is fine.
I
> > sealed the bearing cap mating surface edges with high temp RTV per the
> > manual. All went together easily, torqued up fine, etc.
> >
> > The only idea I have left is that the pressed in oil galley plug at the
> back
> > of the block may be seeping, but to know for sure I'd have to pull the
> > trans. Otherwise, I'm out of ideas. HELP!!!!
> >
> >
>
>

 

"c" <c@me.org> wrote in message
news:IVStc.26664$zn.11604@twister.rdc-kc.rr.com...
> I can't think of a way to do this on an engine that is assembled, but when
I
> put an engine together I normally put a small bead of RTV in the groove of
> the seal that mates with the "rib" on the main cap and the block. As soon
as
> the cap is installed, I turn the crank a few revolutions to let the seal
> center itself (not sure if it is necessary or not, but I do it). This will
> prevent the seepage from behind the seal. If its not coming from there,
> then, like you said, you probably have an oil plug leaking, but if you
> change the seal and it stops for a while, It would make sense that it is
the
> seal.

Well, it used to stop for a3while, but now the %$#^er just kept on leakin'.
I suppose the only way to know for sure what's really going on is to pull
the trans.

>
> Chris
>
> "Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
> news:c98r540s1l@enews3.newsguy.com...
> > My '94 YJ has been a chronic leaker at the main seal ever since it was
> new.
> > The original owner had the main seal replaced at 10 & 20k miles, then
> traded
> > it off at 25k. I had it replaced at 28k, along with a new clutch to
> replace
> > the oil-soaked, chattering original. That seal made it maybe 7k before
it
> > started to drip, I finally had had enough and replaced it again at
around
> > 45k. By 52k it was dripping again, which I ignored until 63k, at which
> time
> > I replaced it yet again. Frankly, the one I pulled out looked as good as
> the
> > new one I put in. The new one didn't waste any time dripping, it
> immediately
> > leaked as bad as the one I took out. ENOUGH!
> >
> > Ok, this much we know: The pan gasket isn't leaking, dry all around.
> Neither
> > is the valve cover gasket, it's as dry as a bone at the back of the cyl
> head
> > and all around as well. The thing drips from behind the separator plate
> > between the eng and trans, and it is motor oil, not gear lube that's
> > leaking.
> >
> > When I pulled the lower rear bearing half it showed signs of seepage
> behind
> > the seal. When I put the new one back in the upper slid in very easily,
> and
> > the lower half fit perfectly. The sealing surface on the crank is fine.
I
> > sealed the bearing cap mating surface edges with high temp RTV per the
> > manual. All went together easily, torqued up fine, etc.
> >
> > The only idea I have left is that the pressed in oil galley plug at the
> back
> > of the block may be seeping, but to know for sure I'd have to pull the
> > trans. Otherwise, I'm out of ideas. HELP!!!!
> >
> >
>
>

 

"c" <c@me.org> wrote in message
news:IVStc.26664$zn.11604@twister.rdc-kc.rr.com...
> I can't think of a way to do this on an engine that is assembled, but when
I
> put an engine together I normally put a small bead of RTV in the groove of
> the seal that mates with the "rib" on the main cap and the block. As soon
as
> the cap is installed, I turn the crank a few revolutions to let the seal
> center itself (not sure if it is necessary or not, but I do it). This will
> prevent the seepage from behind the seal. If its not coming from there,
> then, like you said, you probably have an oil plug leaking, but if you
> change the seal and it stops for a while, It would make sense that it is
the
> seal.

Well, it used to stop for a3while, but now the %$#^er just kept on leakin'.
I suppose the only way to know for sure what's really going on is to pull
the trans.

>
> Chris
>
> "Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
> news:c98r540s1l@enews3.newsguy.com...
> > My '94 YJ has been a chronic leaker at the main seal ever since it was
> new.
> > The original owner had the main seal replaced at 10 & 20k miles, then
> traded
> > it off at 25k. I had it replaced at 28k, along with a new clutch to
> replace
> > the oil-soaked, chattering original. That seal made it maybe 7k before
it
> > started to drip, I finally had had enough and replaced it again at
around
> > 45k. By 52k it was dripping again, which I ignored until 63k, at which
> time
> > I replaced it yet again. Frankly, the one I pulled out looked as good as
> the
> > new one I put in. The new one didn't waste any time dripping, it
> immediately
> > leaked as bad as the one I took out. ENOUGH!
> >
> > Ok, this much we know: The pan gasket isn't leaking, dry all around.
> Neither
> > is the valve cover gasket, it's as dry as a bone at the back of the cyl
> head
> > and all around as well. The thing drips from behind the separator plate
> > between the eng and trans, and it is motor oil, not gear lube that's
> > leaking.
> >
> > When I pulled the lower rear bearing half it showed signs of seepage
> behind
> > the seal. When I put the new one back in the upper slid in very easily,
> and
> > the lower half fit perfectly. The sealing surface on the crank is fine.
I
> > sealed the bearing cap mating surface edges with high temp RTV per the
> > manual. All went together easily, torqued up fine, etc.
> >
> > The only idea I have left is that the pressed in oil galley plug at the
> back
> > of the block may be seeping, but to know for sure I'd have to pull the
> > trans. Otherwise, I'm out of ideas. HELP!!!!
> >
> >
>
>

 

Given that it seems to be the seal, it goes away for a while when you
replace, I would do a couple of things. First I would plastigage that back
brg. Excessive clearance can result in excessive amounts of oil at the
seal. I would also check crankcase pressure. A poorly operating PCV system
will allow a positive pressure to build int he crankcase and blow oil out of
seals and gaskets. In as much as this thing seems to have done it from new
and this is not a chronic problem known to all of these engines I would look
very carefully at the machining of the cap, the block and the crank. When
plastigaging the brg look to see if the clearance is uniform across the
journal.
All I can think of at the moment.
Steve g.
"Jerry McG" <gmcgeorge.remove@frontier.net> wrote in message
news:c98r540s1l@enews3.newsguy.com...
> My '94 YJ has been a chronic leaker at the main seal ever since it was
new.
> The original owner had the main seal replaced at 10 & 20k miles, then
traded
> it off at 25k. I had it replaced at 28k, along with a new clutch to
replace
> the oil-soaked, chattering original. That seal made it maybe 7k before it
> started to drip, I finally had had enough and replaced it again at around
> 45k. By 52k it was dripping again, which I ignored until 63k, at which
time
> I replaced it yet again. Frankly, the one I pulled out looked as good as
the
> new one I put in. The new one didn't waste any time dripping, it
immediately
> leaked as bad as the one I took out. ENOUGH!
>
> Ok, this much we know: The pan gasket isn't leaking, dry all around.
Neither
> is the valve cover gasket, it's as dry as a bone at the back of the cyl
head
> and all around as well. The thing drips from behind the separator plate
> between the eng and trans, and it is motor oil, not gear lube that's
> leaking.
>
> When I pulled the lower rear bearing half it showed signs of seepage
behind
> the seal. When I put the new one back in the upper slid in very easily,
and
> the lower half fit perfectly. The sealing surface on the crank is fine. I
> sealed the bearing cap mating surface edges with high temp RTV per the
> manual. All went together easily, torqued up fine, etc.
>
> The only idea I have left is that the pressed in oil galley plug at the
back
> of the block may be seeping, but to know for sure I'd have to pull the
> trans. Otherwise, I'm out of ideas. HELP!!!!
>
>