Lubricating Light Vehicle Axle Shafts
When a technician installs a CV shaft into a wheel hub assembly, he may want to add a lot of lubricant or anti-seize compound to make the job go easier. While this can help to get the job done, the tech may actually create problems down the road. The tolerance between the shaft and a hub is pretty tight. That prevents any clicking or tapping from backlash but as you tighten the nut to draw that well lubed shaft into the hub, the tight tolerance means that most of the lubricant gets scraped off and pushed into the bell of the hub. Now you have this build-up of lube that has no place to go.
So, as you torque the nut to draw the axle into the hub, you can get something called hydrodynamic lock. Even though the axle nut torque is correct, the axle isn’t really seated because the lube is in the way. As you drive, the lube will heat up and may weep or get flung out of the hub. Now you have a gap between the end of the shaft and the back of the hub. That can allow a loss of axle nut torque and create problems in the wheel end, possibly shortening the life of the bearing.
When installing a CV shaft into a bearing hub assembly, we don’t recommend using any lubricant at all. Instead, just clean the shaft really well with a wire brush and make sure there’s no dirt or debris on the shaft or in the hub.