Shade Tree Mechanic - Crush Sleeve

Old (crushed) Crush Sleeve (left), new (uncrushed) Crush Sleeve (right)

When I was living in Austin I took on some automotive repairs, partly to make a little money and partly to help out some friends. One such project was repairing a limited slip differential in the rear axle of a four wheel drive Blazer. Limited slip differentials work by having clutch plates between the axle gears and the differential cage. They will slip, but it takes a certain amount of force to make that happen. They also require a special kind of oil, sperm whale oil if I recall correctly. Failure to keep the oil up to snuff will cause the clutches in the differential to fail, and that is what happened in this case. They pretty much disintegrated. So it all went pretty smoothly, for working in a dirt driveway with the vehicle up on jack stands. Pretty smoothly that is until it was time to put it all back together. There are two tapered roller bearings that support the pinion shaft. Between them is a crush sleeve. The crush sleeve looks like a short piece of exhaust pipe with a little bulge in the center. The idea is that you tighten down the nut on the pinion shaft until the bearings are snug in their races. To get to that point you will need to crush the crush sleeve. As I recall it requires on the order of 400 to 450 foot pounds of torque to get this done. If the truck had just been another foot or so in the air, it would not have been such a problem. Or it the axle was sitting on the jackstands, but it wasn't. The jackstands were under the frame, and torquing the nut caused the whole axle to twist on it's springs, so it was a real struggle to get even one click on the ratchet with every stroke. If it had been earlier on in the project, I might have considered moving the jackstands, but this was like the next to last step and I just wanted to get done with this job.

Here's someone who did a much more professional job on his truck.

From another site:

Right up until commercial whaling was largely outlawed in the 1970s, a major component of this high-pressure lubricant came from sperm whales.

Update November 2016 replaced missing picture.