Condenser fans , Sleeve or Ball bearing

[hvacker]

The deciding factor for a manufacturer is probably cost. Sleeve bearings seem to be OK for fractional motors. I just haven't had problems with them except with speed controls. Actually I never had the problem as it was solved many years ago when the failure mode was found.
I know ball's load better if loading is a problem. Serious side thrust loading would require a roller or even a tapered roller. As these aren't offered I would conclude they aren't necessary. If price wasn't considered I'd use a ball motor because they are a better choice for longevity. My understanding is a sleeve bearing has an expected life of 10 years. The factory lube has a 5 years and should be oiled. Normal conditions.
I haven;t seen any life expectancy for ball.

[hvacker]

Give the shaft a tug ...no, seriously...a sleeve bearing motor generally has some endplay and a ball bearing motor will not. I actually picked that up from someone here, might have been hvacker.

Wasn't me but that's is a good way to tell. Some ball are fixed on the shaft and won't move. My circle saw is that way.