489 crush sleeve

The best way to go for you is to determine how much preload is on the pinion bearing right now, and repeat that with a new crush sleeve. Otherwise you might ruin the bearings as they get another preload all of a sudden.
The preload usually wears down with age, and increasing it can cause the bearings to fail.
Ideally you should check the preload, take the yoke, outer bearing, and sleeve out of the centersection. Then put in a solid spacer and shim it out to the same preload you measured before. When you've got it shimmed out, install the bearing, a new seal and the new yoke.

Good luck,

Antoon