Growling and vibration 2013

How can I make this short? My 2013 TRD off road is driving me crazy, no help from dealer. It started making an intermittent growling noise and a kind of grinding feeling in the steering wheel approx. 6 weeks after installing Procomp leveling kit and add a leaf in rear.Dealer can't figure out problem, told me I am not the only one complaining. While driving on a smooth mountain road I thought I had a front tire blow-out, it was a quick violent feeling that felt I had lost control for a couple seconds. Some are suggesting the traction control is not funtioning correctly. When the growling occures I put it in nutural are there is no difference in sound or grinding feeling.
Any ideas?

 

Cheap easy fix

http://www.bytortruck.com/product_i...ma-rear-carrier-bearing-spacer-616800-p-93086

 

Ok, let me add that the growling and grinding did not start until 4 to 6 weeks after lift was installed, and whenever Toyota puts the truck on a lift to check it out , the growling and grinding stops and the truck is a joy to drive, unfortunatly it comes back in about 100 miles or so. Toyota has determined there is a problem with 2013 Toyotas after installing a lift, the dealer is not telling me much because I filed a claim and they are waiting for corporate to instruct them on proceeding with my truck, the service writer and manager did say this problem only occures on lifted 2013 and corporate is aware due to the many complaints. They are not sure what is causing the problem or what the fix will be. They said I will be getting a call when corporate instructs them on a fix.

 

That's weird. I wonder what is so different with the 2013's

 

I'm thinking maybe this problem has something to do with factory setups/factory options.

What I mean is I know that with 2nd gens if you run a DB lift like a Fabtech and all things being the same such as both 2nd gens, both being 4 wheel drive, that some 2nd gens due to either brakes or traction control components being in the way, have to run 18" wheels and some 2nd gens can run 17" wheels.

I'm too tired to dig up and explain it better. I'm thinking whatever it was may have been an option on 2012 models and earlier but on 2013's maybe it's a standard change all across the board.

Only problem I have had with 3" of lift front and rear is like the other day I flipped a U turn and the brake pedal pulsed/pushed up against my foot and felt like they weren't doing shit. Also had something similar happen on an on-ramp at 65 MPH, which scared the shit outta me. Would like to know what that's all about. I have heard of it happening to others.