Is it my rotors or my hub/wheel bearings???

[cleam]

I am getting a kind of vibration on acceleration. I can feel the vibration in the steering wheel when I turn the wheel either direction in even the slightest amount. I jacked my explorer up (02 V8 4x4) and I am not sure as to how exactly to tell if my hubs are bad. I locked the steering wheel and I did get a little play when I tried to rock the tire left to right. (Not trying to turn the tire but rocking it) Prior to locking the steering wheel, I spun the tire and it sounds like the brake is rubbing. Is this normal?? Is my rotor bad? Is my hub bad?? Is it both?

 

[Explorerer]

To test for a bad bearing you grab the wheel at 12 and 6 o'clock and check for play. To test for tie rod ends / steering play grab at 9 and 3 o'clock. There should be no play in either case.

Have you considered a problem in the power steering system? Is it a vibration or a pulsing maybe caused by a control valve on the rack? I've haven't worked on my Explorer's PS (yet), but since this vibration shows up while accelerating and with only slght movement of the steering wheel, I'd look there. I don't think those are symtoms of wheel bearings or warped rotors. Unless you have AWD. That could change everything. In that case I'd check the CV joints in addition to the other stuff.

 

[Blacksheep Josh]

I thought to test for a bad bearing you held the tire at 9 and 3 o'clock and rocked it that way. Or is that just earlier models? 12 and 6 was the balljoint test?
Maybe the later generations are way different?

 

[Explorerer]

I thought to test for a bad bearing you held the tire at 9 and 3 o'clock and rocked it that way. Or is that just earlier models? 12 and 6 was the balljoint test?
Maybe the later generations are way different?

Unless the ball joint is extremely bad, the pressure of the spring is usually too strong to overcome and allow movement by hand-on-wheel pressure alone. I use a pry bar to put pressure directly on the joint and check for play. I've never been able to move one by hand. But hey, I'm basing this on my limited experience.

If the bearing is bad, 9/3 may give you movement, but you won't know whether it's a tie rod end or the bearing. If I get movement at 9/3 but not at 12/6, my experience has been that it's a tie rod end. Of course this test is always followed by a visual exam to determine if the movement is in the inner or outer tie rod end.

Another good test for a bad wheel bearing is to drive about 45 mph and swerve L to R a few times to load, or throw weight, alternately on the front wheels. (Don't do this with other vehicles around.) When you load the bearing it will usually let you know if it's bad by making a rough groaning or grinding noise. In other words, when you swerve left, you're loading the right front; swerve R, load LF wheel. If you get the distinctive noise on L swerve, it's probably the RF bearing that's bad, and vice versa. Once you learn the noise you can usually distinguish it from a defective tire.

A warped front rotor can usually be felt through the steering wheel when the brakes are applied; not while accelerating. It's a rhythmic pulsing produced by the unevenness of the warped rotor passing between the pads/caliper. Usually the harder you brake, the more pronounced it becomes. I had a warped rotor on my GMC one time and I could even feel the pulsing through the brake pedal.