Most bearings do not wear out — they are put out. Damage at installation decides more service lives than fatigue does, and the difference is a routine that takes minutes.
Press on the ring you are fitting
Force must pass through the ring being pressed, never through the rolling elements. Driving an inner ring on by pushing the outer ring prints every ball into the raceway — a brinell mark that will hum for the rest of the bearing’s short life. A fitting sleeve against the correct ring face costs seconds.
Heat, do not hammer
For interference fits on shafts, an induction heater brings the ring to a controlled temperature and it slides home without force. The old torch-and-hope method overheats one side, draws hardness, and warps the geometry the grinder worked to achieve. If a hammer is the plan, the plan is wrong.
Keep it clean until the last moment
A bearing straight from its sealed pack is cleaner than any workshop bench. Unwrap it at the machine, not at the stores; a single grain of grit between rolling contact surfaces mills itself into spalling within weeks. Wipe the seat, not the raceway.
Finish with the right first fill
Grease quantity is a specification, not a feeling. Half-fill the free space for normal speeds and resist topping up — churning excess grease overheats the assembly in its first hours. Record what went in and when; the next maintainer inherits the schedule, not a mystery.
