So, I am driving my 96 Tahoe when I slowly back into a boulder on my passenger side (did not hit it very hard) Definitely scraped my tailpipe but no other noticeable damage was visible. Immediately afterward a terrible noise started coming from the underside of the vehicle. It’s pretty hard to tell where the sound is coming from, but I think it sounds like the front end when I sit in the drivers seat but when observing from the outside of the vehicle, my friend said he thought it was coming from the back end..
The noise is only noticeable when I accelerate while in gear. When accelerating up hills, the sound becomes extremely loud but I can lightly accelerate down hills and flat areas without hearing much. The only exception to this is if I hit a bump or take a hard turn while coasting, the same noise can be heard sporadically.
I took it to a shop where a mechanic drove around the parking lot and did a quick look around and checked the brakes which he said seemed to be doing fine, but I don’t think he really had the chance to accelerate hard enough to fully hear what was going on. I told him I had been warned by the previous owner that the u joint was nearing the end of its life, which the mechanic and I kind of concluded was the problem. I’m still very unsure of this diagnosis because the mechanic didn’t seem very confident with that conclusion, and he only charged me $10 for the diagnosis which further weakens my trust in his conclusion. Besides the u-joint being close to death, other preexisting symptoms include an extreme oil leak, loose steering, front end squeaking on bumps, and occasional engine knock when accelerating cold engine. Any ideas on what else to check before taking it to another mechanic will be much appreciated. Thanks.