2002 S10, 4 Cyl, Auto, rear main leak

[Bob]

Reoccurring problem.
My little S10 has aprox 180k.
I've changed the rear main twice since the original.
Last changed about 2 weeks ago.
Leaking again.
Bad vibration at 64 mph which cause the ABS fault light to come for the rear sensor. All 4 tires speed balanced.
I guess my question would be:
Bad crank?
Out of balance flywheel?
Thrush bearings bad?
Transmission?

The truck is great but this thing has me stumped.
Any assistance would be appreciated.
Bob

[Cooter]

I've seen engines come in the shop before for reart main seal replacement that I had to drive the rear main (One piece), in crooked to get it to seal cause of worn out bearings....Not saying this is your problem...How do you know it's the rear main seal? I've seen valve cover/oil pan gaskets leak oil down the rear of the head/block and APPEAR to be leaking from the rear main..

[Bob]

I've seen engines come in the shop before for reart main seal replacement that I had to drive the rear main (One piece), in crooked to get it to seal cause of worn out bearings....Not saying this is your problem...How do you know it's the rear main seal? I've seen valve cover/oil pan gaskets leak oil down the rear of the head/block and APPEAR to be leaking from the rear main..

Thanks Cooter.

Having my own garage and lift makes it easy to remove the tranny and flywheel and see whats going on. The oil is running down from the rear main. The back of the engine is dry. Oil pan gasket is dry except where the oil runs down from the seal. It's got me stumped.

[Cooter]

Also, check to make sure the PCV system isn't stopped up causing pressure to "Blow" oil past the rear main...I've seen it actually blow the rear main seal OUT..

[Bob]

Also, check to make sure the PCV system isn't stopped up causing pressure to "Blow" oil past the rear main...I've seen it actually blow the rear main seal OUT..

That I will have to check.
Thanks
Bob