Chrysler 8.75 Crush Sleeve Eliminator Kit with Shims

A solid pinion spacer and shim assortment that takes the place of the factory collapsible crush sleeve in a Chrysler 8.75 rear end. Instead of squeezing a soft sleeve down with the pinion nut and hoping you stop at the right spot, you set pinion bearing preload with a measurable stack of shims that does not move again.

This kit is for the 489 case dropout only. The 8.75 was built in three castings and they are not interchangeable for this job: the 741 and 742 cases use a smaller pinion bearing and their own spacer arrangement, while the 489 case uses the large 1-7/8 in pinion bearing and the crush sleeve this kit replaces. Identify the case by the number cast into the housing before you order. Manufacturer part number is SK CSC8.75.

On the bench, you assemble the pinion with the solid spacer and a starting shim stack, torque the pinion nut to full spec, and check rotating torque with an inch-pound wrench. Too much preload means you add shim thickness, too little means you take some out. Because the spacer is solid, you can take it apart and reassemble as many times as it takes without throwing parts away, which is the part that makes it worth having on a gear job.

The problem it solves is preload that walks. A crush sleeve is a one-shot part: overshoot the crush and the only fix is a new sleeve and starting over, and a sleeve that relaxes in service lets the pinion bearings run loose, which shows up as gear whine, a wandering pattern, and eventually a chewed up pinion bearing. A solid spacer holds the number you set it to, so a rear end that gets driven hard or towed with keeps its setup.