new whirring sound up front

Ok - so I just had a shop put in new brakes and ball joints in the heep. Upon getting it back, it is is now making a new whirring sound from up front somewhere, sounds like drivetrain somewhere. I assume the axle shafts were removed to do the ball joints so I am wondering if that/the shop could have messed something up. Its also an "oscillating" sound, sort of like a helicopter or something when driving, it it much more prominent under load but definitely there even when coasting.

I know this sound is new from its return from the shop so thats whats got me a little worried. I have my carpet kit removed so I hear a lot and this just sounds like something is "engaged" whereas before it wasn't. I'm not an expert so any help is appreciated.

My ride is my DD 1991XJ sport 4.0HO 5 speed. All stock/no lift. Vac-disconnect up front. Transfer case fluid and both diffs fluid replaced last year, good unless the latest shop just messed something up. Alternator is new, not sure what else may be important. thx everyone-

- TJ

Check for dust cover rubbing on caliper.

I suppose they could have roughed up the bearing to get it out. I've seen people take sledge hammers to the hub flange to break the rust bond that forms. The axle shafts are splined on the carrier end and just slide in and out. They shouldn't have need to been rough with them unless they beat on them to break a rust bond between the splines on the bearing and the outer stub and then generally the only wear point is the u-joint. I would check the dust cover on the calipers and also suspect a wheel bearing.

Thx I will check both these things, especially the wheel bearing. Definitely rusty.

I have the two-piece axle shaft. I was also thinking maybe the "locking ring" or whatever got stuck over on the center link and now my driveshaft is turning whereas before it was not. Is this how it works? I need to check this.

I agree removing the front wheel bearings, then being retightened is what I'm thinking.