Filling a bearing housing past roughly a third to half of its free space, or regreasing too often. The excess churns, temperature climbs, the base oil oxidizes faster, and seals can be pushed out, letting dirt in. In electric motors surplus grease can be forced into the windings. It is one of the most common causes of early bearing failure, and calculated volumes, ultrasound and open relief ports are the cures.
Every motor on that line is overgreased, the last two we opened had grease packed into the windings.
If the bearing temperature rises right after greasing and settles back over a day or two, it got too much. Note the shot count and cut it next round.
Also heard as
- over-lubrication
- overlubrication
Related terms
Running hot
Shop phrase for a bearing, gearbox or motor operating above its normal temperature.
Ultrasound-assisted greasing
Greasing a bearing while listening with an ultrasonic detector and stopping when the noise level drops.
Shot
One full stroke of a manual grease gun, the everyday unit for how much grease goes in.
Purge
To pump fresh grease into a bearing until the old grease is pushed out of the relief port or seal.
Channeling
Grease pushed aside by rolling elements so it sits in shoulders beside the track instead of churning.