In the Shop
As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.
Dec 28, 2013
I don't mean to beat a dead horse, but the topic of eccentric lock collars on bearings just keeps raising questions. This time the question was about removing lock collars from bearings. It should be a simple process, but it can be one of the more aggravating steps in bearing replacement because the darn things are often rusted and frozen in place after being installed by somebody who did or didn't know the proper way to install them.
In a perfect world--which I hope to visit some day--a lock collar is installed in the same direction the shaft and bearing rotates. That lock collar is removed simply by tapping it in the opposite direction of shaft/bearing rotation.
In the real world I begin removal of lock collars by gently feeling with my fingertip the "hole" in the rim of the lock collar, trying to see if the guy who installed it left a punch or chisel mark that tells me which way it was installed. If I feel a mark on the edge of the lock collar's setting hole, I tap the lock collar in the opposite direction to loosen it. IF it loosens, the lock collar is often full of dust or rust or debris so that, even when it rotates and releases from the eccentric, it won't slide off the bearing and shaft.
In that case, I generally hose down the divide between the bearing and lock collar with penetrating oil, then grab a pair of slip-jaw pliers, clamp them on the lock collar, and try to wiggle and rotate it back and forth on the bearing. I rotate it till it re-clamps in one direction, twist it in the opposite direction till it re-clamps, then use those two "limits" to determine halfway between those locking points--which should be the place where the eccentrics are dis-engaged and the lock collar will slide off the bearing.
If, after a couple tries with penetrating oil and slip-jaw pliers, the lock collar still refuses to come off, some mechanics use a die grinder with a cut-off wheel to cut off the stubborn lock collar. Me? I grab a torch and melt the sucker. I'm probably going to have to eventually burn the bearing off, so I just cut to the chase and start melting metal.