Bad Tacoma Good Tacoma

Back in January (2015) I purchased my first Taco - a 2008 TRD OR, 2.5" lift, TRD front skid, Rocky Road Outfitters super sliders, 265/75 Goodyear Duratracs. Two things i learned about that truck. 1) I LOVE Tacomas!!! and 2) Tacomas are NOT indestructible. I soon found out that many of the 86k miles on that truck were spent in the back country on wash board roads, possibly at high rates of speed. It was previously owned by an environmental consulting firm who specialized in field studies. Over the course of 3 months I was able to detect 3 different sources of vibrations all at differing speeds. I have read about Tacoma vibration woes on these and many other forums before, but it was the first time experiencing them. Sounds like it is tough to remedy. In addition to the vibes, I discovered many fender and bumper fasteners/bolts/clips missing and the passenger side rear of the bed had about 1.5" of outward movement. The day I traded it in it developed an intermittent "grinding sound" at low speeds and would cease once driving for a while. Anyway I traded the truck in on a 2015 TRD OR and so far I absolutely love it! I traded over the tires and the TRD skidplate from the old truck, but opted not to lift it for fear of vibrations. My question is were the vibes likely due to the lift only OR because of the combination of the lift and lots of back country travel.