ball bearing failure and blower wheel seperation.

[RoperJr]

Our tech did a spring service on 5 packaged York units. He replaced fan belts and I confirmed proper tension. About a month later 2 units had issues. One has a destroyed ball bearing that came apart and the other has a blower wheel that separated from shaft. What are some common reasons this would happen? The York units are within ten years old.

[hotrodrob]

the bearing that came apart, was it on the drive side or opposite side. proper tension can be a broad term. on packaged units proper tension is like almost a loose belt. if it squeels at startup your probably ok. the bearings on the 3/4" shafts on most small capacity packaged units are not that durable and too tight of a belt can destroy them. considering the age of the units you probably got the life out of those little bearings.

I have seen blower wheels come loose so i tend to check the setscrew on them during a major pm.

[RoperJr]

Bearing failure on both units are on opposite of drive side. And the blower wheel got completely beveled out.

[valdelocc]

A month is way too long to blame it on the tech, in my opinion the failures are not related to what the tech did although he may had missed the trouble signs.
are you sure they were "ball bearings"?

[RoperJr]

The actual balls of bearings were on the bottom of unit. I know our client is questioning if our service caused these issues. I can certainly see how put on a new snug belt will bring to face these issues that were doing ok on old loose and worn belt.

[hvacker]

Ball bearings are designed fer a radial load. In other words straight down. I might look at the blower sheave not running true or the fan riding it's fan curve causing side thrusting.
Over lubing can pop the bearing seal and allow contaminants in.

[hands]

If belts are rolled on without loosening the motor, it can cause bearing damage. That being said, even if he rolled them on, the bearings were most likely going out anyways.