Home › Forum › Ask A Member › Time for a new crankshaft seal? › Re: Time for a new crankshaft seal?
Scott,
Just so you know, this is not something that you can check with the motor all assembled. Just don’t want you to waste time looking for this! When the crank halves are separated, you can see the oil return hole in a groove in the crank case casting. It is pretty small. I don’t think I have ever found that passage blocked, but I guess it could happen. I have seen some guys install an o ring on the top bearing by mistake…..that could/would block the hole. Especially if they added sealer to the o ring. The intake manifold creates a siphon effect, that draws the oil/fuel mixture from the top of the crank, back down to the intake to be re used by the motor. That, in conjunction with the top seal, prevents fuel/oil mix from exiting the block onto your mag plate.