sanded1

Has anyone seen a 455 crankshaft develop small hairline cracks 180 degrees apart in the rear main seal area ? 25 years after a major restoration including a complete engine overhaul I pulled my 455 for a reseal and inspection. While replacing the rear main seal I noticed (2) hairline cracks about 3/8 of an inch long running length wise 180 degrees apart where the rear main seal is. My question is aside from the obvious is this thing junk ?

olds 307 and 403

Put up pics.

sanded1

Not sure how to do this

joe_padavano

Never seen anything like that before. Are they exactly 180 deg apart? If so, that's suspicious. The stock rope seal is supposed to be trimmed against the crank. If the seal was replaced with the crank in place and the engine in the car, it's possible that the installer cut or hammered too hard on the ends of the seal, causing scratches that turned into cracks.

sanded1

Your right upon closer inspection (polished the area) they are scratches from a previous install. Thanks, I just saved $500. for a crank