2005 Sport Trac, 2WD, automatic trans w/ aprox 80K milesA few months ago there was a grinding sound from the rear of the truck that increased with speed (a whomb, whomb, whomb type sound) and even a clicking when I reversed. I was doing my breaks and noticed there was some play in the wheel when pushing/pulling but also that when I turned the wheel (both wheels up and trans in neutral) there was some side to side play (not sure if that is normal or not). Also when driving the truck slowly wobbles at low speeds and begins to shake at higher speeds. I noticed that this isn't constant and seems to greatly reduce after a left hand turn. One place told me it was the differential but I am not sure and don't want to spend a bunch of money if it's a bearing as I can replace the assembly myself for under $200.
Sounds like outer wheel bearings but it could be the differential bearings as well. The only way to know is replace the wheel bearings and see if the noise stops. I'd check the gear oil level as well since if you were low on oil that would kill the bearings and the differential. If it's low make sure you add the specific kind for your axle.
