quick dumb question, pinion nut

[KramerSwinger70]

I asked Dr.diff about some parts and in an email back they asked for the "socket size of the pinion nut" to determine the pinion spline count. I would need to ask my father to check this for me, as I am overseas in Japan.

so what am I measuring, exactly?

while Im at it, the casting number is the last 3 of the serial, correct?

Thanks!

 

[doug 371]

the rear of the driveshaft attaches to the pinion yoke...the nut he's asking about holds that yoke on...your dad will have to undo the driveshaft to fit a socket on the nut...yes usually 741 742 or 489 found on drivers side of case assuming its an 8.75

 

[69MOPE]

Coarse spline = 1 1/8" nut
Fine spline = 1 5/16" nut

 

[KramerSwinger70]

thanks!