Set up my first 9" a few weeks ago, and I'm finally getting around to to finishing it off by setting the pinion bearing pre load. I'm using a solid shim spacer. Looking around the interwebz I have found a few guys that claim with a solid spacer not to run any pinion bearing pre load because the spacer wont "absorb heat" like a crush sleeve will, and can actually expand enough to cause damage to the pinion bearings. Anybody heard of this or had this experience themselves? I already have it set up with the pre load in spec of what it should be with a crush sleeve, but it's still out the truck and easy to change if need be.