87 745t manual - flywheel rubbed rear main seal?

After observing a big ole honkin rear main leak on my new 745, I
pulled the trans and all that crap, got the clutch off and flywheel
this evening.

Now, the timing sensor is sheared off by the flywheel. I don't need it
I understand, so that's fine.

The rear main is toast bigtime, it's actually been rubbed by the
flywheel pretty badly.
Removing the seal from the housing, it don't look like there is a way
to stop one from not seating it far enough in, so maybe that happened.
But looking at the sheared off sensor, and the ground up rear main, I
can't help but wonder if the flywheel is, something, not where it
ought to be, wrong one, something. The clutch is pretty new, Volvo
labeled, and I bet it was done at the dealer. Another possibly notable
thing is the PCV system was a little crudded up, I think there was
excess pressure in the crankcase, wouldn't think it's be enough to
move the metal part of the seal, but who knows.

Thoughts? I'd hate to stick it back together and it tear up a new rear
main again.
I assume one just installs the seal flush with the top of the housing?

Thanks..

 

This is a question for more knowledgable people here, but I suspect the
thrust bearing has failed. It shows up as fore-aft play in the crankshaft,
but that's the limit of my knowledge.

Mike

 

The flame trap housing or crankcase breather clogging is the usual cause
of blown seals. You'll want to make sure you don't have positive
pressure in the crankcase. The flywheel bolts straight to the crank and
all the 4 cyl Volvo flywheels are interchangeable to that extent so it's
hard to imagine something going wrong there.

 

Well being that it sheared off that timing sensor I think I should
find a dial indicator and check the crank play fore and aft, I'm told .
010 is about the safe limit, more than .040 and it's probly the crank
thrust surface worn in addition to the bearing.
Looks like I can jack the motor up, pull the pan and change the thrust
bearings. I sure hope the crank isn't worn. Motor only has 127K and
I have good service records on it, bummer..