Bearing, Rotor, or Caliper???? 03 Aviator AWD

[tjgorn01]

Need some help troubleshooting a cyclical grinding/growling noise on my AWD aviator. Sounds as if it is coming from from the front drivers side. Just replaced rear pads last week. Can be heard best when coasting and it varies as the speed varies. Initially thought - warped rotor but no real grabbing during braking or feedback in the steering.

Put the vehicle up on jack stands all the way around and removed the wheels/tires. Hand rotating rotors did not show much runout (.001 -.003/4) total variation in readings. Started up vehicle and put it into drive. Front drivers side wheel turns very quickly, rear drivers side wheel slower, rear passenger slider very slowly, and front passenger side hardly turns at all.

Did notice a sound from the rear brakes of cyclical grabbing with the wheels removed. However - why is the front passenger side pretty much not turning at all? I can turn the rotor by hand.

Any ideas?

 

[Albino 94LTD]

Some random thoughts.

Does your Avi have AdvanceTrac? (not necessarily applicable in this instance)

Grinding in the rear could be the parking brake shoes inside the 'hat' part of the rotor, have you checked them yet?

One front wheel turning faster could be you have open front diff and the slow wheel is simply viscous coupling itself with the other (gear oil moving around making it turn).

Can you stop that wheel from turning by hand? That would confirm it is just the gear oil making it move.