You need a sleeve on the crank pulley to cover the groove on the sealing surface.

A quick fix (without a sleeve, or when none is available) would be to grind 1/4" off the back of the seal, installing it all the way in. This moves the sealing surface to a new spot on the crank pulley, sealing the leak.

"A young man who does not have what it takes to perform military service is not likely to have what it takes to make a living." - John F. Kennedy

Proud owner of an 88 Montero (with a blown engine).