Leak in Np 208c rear output seal after New carden shaft install

[Supervillainmc]

I put new heavy duty leafs in my 87 K5. Had to install rear Carden Shaft and 4 degree wedges because of driveline issue. Everything is finally good except now, but I have a leak in my rear output shaft seal only when truck is on. When it’s parked it don’t leak. My mechanic said that he thought the shaft was 1/4 in too big. The truck runs fine. No more vibrations.Can that cause the seal to get damaged? Any help will be greatly appreciated. U guys helped me a lot in the past. Nobody more qualified. Thx

 

[Bent77]

Check the seal on the output, make sure the shaft didn't clip it.
Make sure there's not supposed to be a plug in that new driveshaft (bottom of the splines)

 

[Supervillainmc]

Thank U. I will pull it today and check it. If the seal is damaged I’ll replace it