Bearings are the joints of industry. They can last for ten years if installed correctly, and three days if installed incorrectly. Many devices have abnormal noise, heat generation, and short lifespan, and the root cause is not the quality of the bearings, but rather improper installation and disassembly. Today, I will directly introduce the latest 2026 bearing assembly and disassembly process and key points for avoiding pitfalls that are commonly used by factory technicians. Novices can get started, while experienced workers can improve efficiency.
Before installation: Three step inspection work
1. Cleaning
Bearings should only be opened before installation! The shaft, seat hole, and tools must be free of iron filings, oil stains, and dust. Even a small amount of impurities can reduce the lifespan of the bearing by half.
2. Check the size with the model number
The inner diameter, outer diameter, roundness, roughness, and interference fit should be controlled within 0.02~0.05mm, with too tight cracking and too loose shaking.
3. Environment
It is best to operate in a clean area/dust cover, and it is prohibited to install naked in workshops with flying dust.
Three step installation of core
1) Cold pressing method (for small and medium-sized bearings)
Use copper sleeves/soft metal pads to only press the inner ring (shaft matching) or outer ring (seat hole matching), and it is strictly prohibited to press the rolling elements!
Do not use a hammer to strike directly. It is necessary to evenly apply force with a sleeve to avoid tilting or rolling damage.
2) Hot fitting method (medium to large size/large interference fit)
Oil bath heating: 80-100 ℃, never exceeding 120 ℃ (tempering will soften).
The bearing suspended grid is heated without touching the bottom of the pot to prevent local overheating.
Quick assembly after thermal expansion, axial locking immediately after cooling to prevent movement.
3) Hydraulic/Lamar Assist (Heavy duty/Frequent Disassembly and Assembly)
Hydraulic nuts are preferred for large interference fit, with even pressure and no damage to the shaft neck.
Conical bore bearings: Monitor clearance changes while tightening to avoid excessive pre tightening.
Dismantling: Violence=Scrap!
1. The puller must only clamp the inner ring hook on the inner ring end face, and it is strictly prohibited to hook the dust cover or holder, as it will break when pulled.
2. Hot disassembly is safer. When the outer ring is difficult to disassemble, the hot air gun locally heats the outer ring (around 100 ℃), expands it, and easily removes it.
3. Low temperature pre disassembled liquid nitrogen/dry ice cooled bearings (-80 ℃), with inner diameter shrinkage, can be removed directly without knocking, and the secondary utilization rate ranges from 35% to 70%.
5 Deadly Misconceptions That 99% of People Make
1. Use a hammer to directly strike the bearing → the raceway cracks and the cage deforms
2. Hot installation exceeding 120 ℃ → bearing annealing, hardness drop, and life return to zero
3. Simultaneously pressing the inner and outer rings → uneven force on the rolling elements, early pitting corrosion
4. Improper/excessive addition of lubricating grease → heating, leakage, and soaring resistance
5. Failure to turn the car after installation → lagging, abnormal noise, and damage upon startup
