Pinion Preload: Shims VS. Crush Sleeve

Which is better? A crush sleeve or shims for pinion bearing preload?


Background: My dads 95 Impala SS with the LT1 needs a tranny so he is swaping in a T56 manual in place of the blown up auto and is rebuilding the rear end with new gears, bearings, seals.

He is installing Precision Gear 4.10 gears and a Torsen gear driven limited slip in the factory GM 8.5. The 6th gear of the T56 has a .5 over drive so the 4.10s shouldnt be a problem at highway speeds. There is a kit that replaces the crush sleeve with a solid spacer and shims and is less than $20 for the GM 8.5. Is it worth it?

Just to make this Jeep tech, would this help the F8.8 rear axle? I have a crush sleeve in it now but have seen kits that replace the sleeve with a solid spacer and shims. So is this spacer and shims worth it for a Ford 8.8 rear?

Thanks,

AARON

Never done it but it would seem like a spacer and shims would make taking it apart and puttting back together until proper preload was acomplished easier than replacing a crush sleve everytime.

Couldn't tell you on the 8.8, but on a Dana 30 it makes a big difference. The newer LP D30s use a crush sleve, and can be a PITA. The HP D30s use shims and seem to set up easier and more accurately.

The crush collar is faster overall. thats why they they have them.

The key is to not install the crush collar till you have a good pattern. The only downside to the crush collar besides the fact that once you use it its done, you cant back it off if you overtighten it. but also the amount of torque requred to crush the collar.
so if you bust the yoke on an axle with a crush collar then you need to replace the crush collar, seal and pinion nut.
the yoke on a shim axle can be unbolted and re-tightened without loosing preload.

The crush sleeve can give over time, if you can use shims, I would.