I have the original OEM seal and the three new 3543 seals in front of me. They are basically the same ID (within 0.010" - it's hard to tell as the OEM seal is not inside its cage so the diameter is not perfectly consistent).
When I installed what's left of the OEM seal on the shaft, it was a MUCH tighter fit than the new seal. And, that's without the spring. The newer seal is more flimsy (maybe that's because the older OEM seal is more brittle after 15 years, but it's not at all splitting and still very pliable - it's just more rigid than the new seal).
The OEM seal has a black seal while the new ones all have dark orange colored seals.
The sealing lip of the new seal is a fine edge (the corner of a triangle) and the OEM seal has a much flatter sealing lip where the surface of the seal would contact the axle over more area.
Bottom line: the THREE new seals leak more than the OEM seal did with the spring knocked out of it.
I'm getting DELCO seals tomorrow (well, my wife is, for me, while I'm @ work).
I'm hoping this cures the issue as I'm PISSED that I spent a whole weekend changing the oil pan (any of you who have done that know what a royal pain in the ass it is) to CURE an oil leak (the bottom of my engine is BONE DRY) just to have this stupid axle seal leak like a sieve.
