Rebuilding a '56 3600 & have replaced all the seals (and a lot of the bearings) in the driveline (it's a NAPCO, so $ times 2 for everything).

Finally at the stage to fill things up with oil this weekend and the driveshaft heading into the front axle starts leaking from what appears to be the splines of the pinion gear (not around the seal!?! Oil is coming out from the end of the yolk, not behind the dust cover).

Any ideas what might be causing this, and how to fix it? Is it wore that bad (doesn't appear to be?) that it's leaking through the splines? So far, the rear one is fine/no leaks.

I've thought about siliconing the splines before sliding the yolk on, but that seems like quite a shortcut...

Thanks.


1956 Chevy 3600 NAPCO 4x4
1955 Second Series Chevy Short Box
1956 Chevy 3100 Short Box


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