"Inside-out" seal

[Ed Landstrom]

Has any one found a source or modern replacement for the seal (GMC #2199398) in the rear spring mount on a DUKW. I don't know if the CCKW is identical, but I don't see why it wouldn't be.

For the amusement of anyone who hasn't had to cope with this seal, it's a 2 7/8 x 3 7/8 lip seal. What makes it unique is that instead of being pressed into the bore with the lip sealing on the shaft, it's pressed onto the shaft and has the lip on the outside, so it seals against the bore. People in bearing shops can't believe it exists, even when I show them my old one.

Apparently, the early trucks used a felt seal instead of a lip seal. I could make the felt part, but it requires a couple of retainers which I don't have. Besides, I assume the reason they changed was that the felt wasn't satisfactory.

Does anybody know why GM used such a strange seal? I've thought of modifying the part to take a conventional seal, but when I redesign something I always worry that there was a good reason that I've missed for doing it the original way.