Replacing the pinion seal on my 1968 442 "Type O" as the original was starting to seep gear oil. The original pinion seal has a lip...giving it a stop point. The replacement seal (National Seal 2043) has no lip and can be driven 1/8" to 3/16" past the face of the front of the axel. Should the seal be flush and will this leak??

 

I would say put the new seal at the same depth as the original that has a lip to set the depth.