Ag equipment, in particular, tends to use bearings which have eccentric collars. There seem to be two types of brackets which mount them: a.) sheet metal flanges which pinch the outer race, and b.) cast pillows which they are inserted into, and which may allow pass through of grease from a zerk in the pillow to the outer race which may also have a zerk.

The question is which way the locking collar should be installed. Some say with the rotation of the shaft, which would tend to lock it against the inner race. Others say it doesn't matter, because either way the bearing will lockup on the shaft.

Also, the conventional wisdom seems to include locking the collar as tight as possible. However I have seen it written that can cause the inner race of the bearing to crack, and ultimately affect the underlying shaft causing wear. I have seen inner races so cracked.

Can anyone with a bunch of experience replacing this type of bearing chime in with installation wisdom?

  • Researching things further I found that the collar, if installed as @SteveRacer points out, self-tightens with tremendous forces as things wiggle with torque and vibration. So the collar need not be super tight.
    – mongo
    Commented Jun 8, 2019 at 7:20

1 Answer 1


In general, I think it should be installed so that it "self-locks" with the rotation of the shaft.

It doesn't require much pre-loading, if any. This arrangement is usually for a shaft that transmits power only in one direction - torque load in the opposite rotation direction tends to uncouple the eccentric.

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