Hi all I have an 85 4runner auto (I know ). I bought a 4inch lift kit and put that in. After a few months I noticed a slight hum, coming from the center console area, almost between the 2 front seats. I only notice it when I'm on the freeway going about 65mph and up, and ONLY yes ONLY when I let off of the gas pedal. So it only happens after I stop accelerating by letting go of the gas. It will last for a second and then stop, like its catching up or something. Now that hum has become a slight grind. My guess is the sound is coming from around the t-case or driveshaft areas, and more towards the front of the vehicle versus the back. I'm so far from being a mechanic and would appreciate any helpfull info on this matter. So I dont sound like an idiot to the mechanic I take it to. Speaking of mechs, if any one could refer me to a place that would be cool too. I'm in L.A. CA. Thank You. By the way I bought the runner with a little more than 200k on it. I give it an 8 almost a 8.5 on the int. and the a.c. still works!!! For $1200. The guy did not know what he had. It drove fine when it was stock. The humming and grinding started after the lift. (4inch Pro-Comp) on 32's.

 

I would think driveline angle or u-joints, tires low or not balanced, transfer case gears, bent driveline's or rim, old bushings....could be a number of little things.