So Im doing my own 9 inch center section build, and the step by step, how to assemble everything is pretty straight forward, except for the orientation of the yukon solid spacer and shims. I have checked yukon's site, searched on google and cant find any info on how to install the spacer and shims... has anyone used this spacer? It is a 2 peice spacer, one piece is tapered on one side and recessed on the other ( i assume this is where the 2nd piece and any required shims go).

 

I'm just speculating as I've never seen one of those before and don't have it in front of me, but If the smaller spacers fit in the concave part of the larger spacer I would assemble them this way: I would first install the thin shims into the concave part of the large spacer then install the thicker small spacer. You probably set the preload by selecting the correct combination of thin shims. With the shims installed this way the fragile thin shims will be protected inside the large spacer and under the thick small spacer.

 

I kinda assumed the shims fit between the concave spacer and the smaller spacer, but does the small spacer or the angled side of the big spacer face the pinion gear?

 

shims fit between the two.