You probably turned the crank from the front of the engine, so unless you used a bar against the flywheel to lock it while, or if you removed the front main bolt, there is no way turning the crank could damage the rear seal. However I have noticed that when you make repairs to these engines and bring the other seals back to a restored level, the weaker ones give out. Also if you have blowby, or a clogged crankcase. If your crankcase isn't ventilated properly and pressure or vacuum builds it can cause a weakened seal to fail. Unfortuanatly there is no way to replace the rear main seal without removing the engine or the transmission, preferably both, and then you are getting into all the MAW's! I would check your crankcase ventilation that it is properly routed and not clogged, check your compression to rule out blowby, maybe do a leakdown test, and then I would ensure that is where the oil was coming from. I lost my front main seal due to a crankcase ventilation problem, I am glad it was not the rear. Good luck!
B

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Brian W. Heitman

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