Can I reuse the Diff pinion crushed sleeve?

[sapote]

I ask this question since I just read a post about the pinion seal was set a little too deep.
Most people when replacing the pinion seal, we just marked and tighten the pinion nut back to its original position when decided to keep the old crushed sleeve. But why a crush sleeve is needed in this case for preload 2 taper roller bearings? Why most front wheel bearings with the same taper bearing uses no crush sleeve?

To crush the new sleeve I would imagine it needs 60 ft lbs or more. When reuse the crushed sleeve and just tighten the nut to the original marking, I bet it takes much less. What harm can this cause?

I could preload the pinion bearing without using a sleeve (just like front wheel bearings in many older cars). What can go wrong with no sleeve?

[bigjae46]

There is a ledge on the pinion which the crush sleeve sits on. Then the outer bearing sits on the other side of the crush sleeve. I guess its possible that the bearing could walk up or down the pinion shaft.

Why would you NOT put a crush sleeve in? That part is cheap and setting preload isn't all that difficult. Big battery impact, one short blast, check preload and repeat until 14-16in/lbs.

You do the pinion preload LAST. It goes

1. carrier preload
2. gear pattern
3. backlash
4. pinion preload

Press the outer pinion bearing on, install the seal and then crush the sleeve.

[sapote]

1. There is a ledge on the pinion which the crush sleeve sits on. Then the outer bearing sits on the other side of the crush sleeve
2. I guess its possible that the bearing could walk up or down the pinion shaft.
3. Press the outer pinion bearing on, install the seal and then crush the sleeve.

2. IF the bearings are preloaded (by torquing the nut until a proper drag torque is measured) then the outer bearing cannot walk anywhere even fraction of a millimeter , even with no sleeve to block it. Its outer race was pressed into the diff housing and so the bearing cannot enter further than its fixed outer race. It cannot walk out as being blocked by the nut.
3. The outer bearing doesn't need to be pulled or pressed on. It should slide on the pinion shaft without much force. And this is why a sleeve is required here. IF they had designed it such that the outer bearing is required to be pressed on the pinion, then there is no need for the sleeve. But this design would cause so much trouble to remove the outer bearing.

Because the design is to allow the outer bearing to be easily removed/install, it requires the sleeve. Without the sleeve, the inner race would spin on the pinion, leading to damage on the bearing and the expensive pinion/ring pair (only supplied as a pair).

Btw, the front wheel bearings -- on those cars that require periodic adjustment -- should have used a crush sleeve in between but they don't. They got away with the design because the bearing inner races were loaded by the car weight.

[sapote]

So if the final torque on the nut is not more than 20Nm, there is a risk of having the outer bearing inner race spun on the pinion and destroy it.
I would also measure the pinion drag whenever the old leaking seal needs replace, to see how much the old roller bearings have loosen up. The spec should be [1.36 to 2.6 Nm]. If too loose, I would add a thin shim on top of the crushed sleeve and set the drag torque again. This also needs more torque on the nut to crush the sleeve, and this ensure the inner race won't spin and destroy the pinion.

also, the new seal drag should not be included to the final pinion drag torque.

[bigjae46]

The sleeve and the input flange are what hold the bearing in place. The purpose of preload is to ensure the bearing stays seated in the race and prevents wobble and maintains the backlash and gear position. Otherwise you risk damage to the pinion and ring gear.

You can install a solid collar instead of the crush sleeve. Just have a machine shop make one. I would imagine you just pull the crush sleeve and and measure it.

Should be similar height as long as you retain the same pinion shim.

[sapote]

You can install a solid collar instead of the crush sleeve. Just have a machine shop make one. I would imagine you just pull the crush sleeve and and measure it..

If the solid collar was machine the exact length of the crushed washer. But then why would someone want to waste the time to remove, measure its length, and pay the shop to make a collar with the exact spec of the crushed sleeve?

[bigjae46]

If the solid collar was machine the exact length of the crushed washer. But then why would someone want to waste the time to remove, measure its length, and pay the shop to make a collar with the exact spec of the crushed sleeve?

If you change gearing a lot, you can make a machined sleeve to match the gear set. The crush sleeve is easier...costs $10.