12 Bolt Pinion Seal Help

[WhiteCST]

Alright guys I need some help. I have a 12 bolt out of my 68 C10. 3.73 gear ratio and I believe a 9.75 ring gear. I can’t find the proper pinion seal for this thing. The old seal didn’t have a part number so I’m out of luck there as well. I know for certain it’s not an 8460 or a 6808. Both of those seals are too small and will easily just sit in place. Anyone have any insight on this?

[Mike C]

8.75" if it is a 12 bolt truck. With GM numbers on the ring gear, that would be my guess.

I have never had a problem just going to the parts store and asking for a seal for the vehicle. But the date on that Ring gear, if it is 1 of 67 would not have been found in a '68. Have the parts guy look up the seal for a '67 12 bolt. I would not have thought them to be different, but you never know.

[gmc684x4]

The truck 12-bolt uses a smaller inner pinion-bearing (1.438 inches versus 1.675 inches)
Could the parts guy given you a seal for a car 12 Bolt ?

On another thread on here the fella stated he got a seal from chevy that fit better then the Nappa seal

https://www.chevyhardcore.com/tech-s...rearend-guide/

[WhiteCST]

Well after quite a bit of searching I determined an 8622 National seal fit like a glove. Not sure what application it’s for, but if you find yourself in the same situation as me give 8622 a shot.

[WhiteCST]

I’ve also determined that the same seal is used on the front diff for 80’s K series. However, I am still unsure of what 12 bolt I have

[StingRay]

The truck 12 bolt is 8.75". They were used from the 60's to the 80's and there are literally millions of them out there. The parts should not be hard to find.