Master Spline on Driveshaft.

[George7941]

I pulled off the driveshaft on my truck (2WD, one piece driveshaft) and I see that the slip yoke has a missing spline but the transmission output shaft does not have a master spline and, so, the yoke can be fitted on to the shaft any number of ways (as many as there are splines on the shaft). The FSM intructs you to fit the driveshaft back on in the exact same position it came off but then why did GM not put a master spline on the shaft?

The only explanation I can think of is the the same yoke gets used in different applications and perhaps in a different application the transmission shaft has a master spline and it is necessary in that application that the yoke goes back on in the same position.

 

[Boomer]

Did you mark everything as you took it apart? Always a good thing to do!

 

[George7941]

Yeah,I did. You can see the white chalk mark at the very top of the yoke in the first photo.

I will put everything back together the way it was even though I don't think it is necessary at the front because there is no large rotating mass at the front. At least at the rear there is the pinion flange which might have a slight imbalance to it and it is being cancelled by the driveshaft.

 

[punisher]

The missing spline on the yoke is........an air bleed.

 

[George7941]

Wow, who would have thunk that!

Learn something new everyday.