Originally Posted by Scottrik

What Arn0 has done is exactly what makes the Slapmaster kit what it is...he's done the collar so it picks up the OUTER race of the hub bearing rather than the now standard collars that pick up the inner race. This hand-machined collar is why the SlapMaster kits run $20-25...yeah the thrust bearing is a $3 part, making that collar and then packaging and distributing them so they're readily available to all and making sure the shop makes an acceptable mark-up is where the "magic" is. Hell...I've got access to a lathe but if Brian's willing to do 'em for what they sell for I wouldn't bother. Time better spent on something else. Like learning to drive.

Adam, you'll see several well-intentioned people saying just buy a $3 thrust bearing from XYZ Bearings and throw it in there. It HELPS, but it is by NO means the solution. It will make the diff spin a little more freely but it doesn't protect that outer bearing from improper side-loading. That side-load is present at all times when the diff is tensioned but it spikes WAY over the top every time you hit a barrier with your rear wheel/axle. SlapMaster's and Arn0's collar eliminates that impact load from affecting the bearing. End result, longer bearing life and no more heats ruined by poor handling because the bearing got notchy when you hit.