Why Bearings Fail — Diagnosis Guide

A bearing that fails early has almost always been damaged by something else — contamination, bad fitting, wrong clearance or a failed seal. Replacing it without finding the cause means the new bearing fails the same way. This guide explains how to read the damage on a failed bearing and what it tells you.

စောစီးစွာ ပျက်စီးသော bearing သည် အခြားအကြောင်းရင်းကြောင့် ဖြစ်လေ့ရှိသည်။ အကြောင်းရင်း မရှာဘဲ အစားထိုးပါက အသစ်သည်လည်း ထပ်ပျက်ပါမည်။

1. Contamination — အညစ်အကြေး ဝင်ခြင်း

Dust, sand or water enters past a damaged seal and grinds the raceway. The surface looks dull and scratched, and the grease is gritty or discoloured. This is the most common cause of early bearing failure in Myanmar road conditions.

What to do: replace the seal as well as the bearing, and check the housing is clean before fitting.

2. Fatigue spalling — မျက်နှာပြင် ကွာကျခြင်း

Small flakes break away from the raceway, leaving pitted patches. This is normal end-of-life wear if the bearing has run a long time. If it appears early, the bearing was overloaded or the wrong rating for the application.

What to do: if the vehicle is regularly overloaded, fit the correct heavy-duty rating rather than the same bearing again.

3. Brinelling — impact damage — ရိုက်ခတ်မှု ဒဏ်ရာ

Evenly spaced dents appear in the raceway, matching the spacing of the rolling elements. This is caused by hammering the bearing into place through the wrong ring, or by shock load.

What to do: this is a fitting fault. See the fitting guide — the force must always pass through the ring being pressed.

4. Overheating — အပူလွန်ကဲခြင်း

The bearing turns blue or brown, and the grease is burnt black and hard. Causes are too little grease, too much grease, insufficient internal clearance, or a shaft fit that is too tight.

What to do: fill a rolling bearing about one third to one half full of grease, not completely. Check whether the original was a C3 clearance bearing.

5. Misalignment — မညီညာမှု

The wear path runs diagonally across the raceway instead of centrally around it. The shaft and housing are not square to each other, or the housing bore is worn.

What to do: check the housing before fitting a new bearing. Where some misalignment cannot be removed, a spherical roller bearing is designed to tolerate it.

6. Creep — the bearing turning in its housing — Bearing လျှောနေခြင်း

The outside of the outer ring or the bore of the inner ring is polished bright, and the housing or shaft is worn. The fit was too loose, so the ring rotated instead of the rolling elements.

What to do: a new bearing alone will not fix this. The worn shaft or housing must be repaired or replaced.

7. Noise as a first warning — အသံဖြင့် စစ်ဆေးခြင်း

• A rumble or growl that changes with road speed but not engine speed points to a wheel bearing.
• A noise that changes when the vehicle is steered left and right points to the wheel bearing on the loaded side.
• A whine that follows engine speed points to a gearbox or accessory bearing.

ကားအမြန်နှုန်းနှင့်အတူ ပြောင်းလဲသော အသံသည် ဘီး bearing ကို ညွှန်ပြသည်။ ကွေ့သည့်အခါ ပြောင်းလဲပါက ဝန်ပိုနေသည့်ဘက်ခြမ်း၏ bearing ဖြစ်သည်။

Bring the failed bearing to the counter or send photographs to our trade desk. We can usually identify both the replacement and the cause from the damage pattern.