[Mercougary]

You don't actually need the Kent Moore barrel spline sleeve holder handle. 1/4x1 flat bar stock and the snout off the torque tube driveshaft. If you have a can of plasti dip you can form the grip if necessary. OpelSpyder has documented this before on the forum and YouTube. Way stronger.

 

[Mercougary]

Looks like a custom tool to me. All custom tools are DIY.

 

[Mercougary]

Looking closer at figure 4B-8, I don't think GM / Opel came out with a socket to replace this. I think the socket is on the nut, not the splines.

I puzzled over this figure 4B-8 for quite awhile because of the J-22932 caption. All that one could accomplish would be to rotate the assy. Doesn't do any good to hold the pinion from turning if you can't get to the nut. Disregard Post #2 in this thread and note the discrepancy in the FSM. If one of the moderators would be so kind as to edit Post #1 to reflect the use 1/4" x 1 1/2" bar stock, my error could be corrected.