New guy here, needs help

[Cake]

I own a 2014 chevy silverado 1500 4x4,base model, 21,000miles. I've been wanting this truck since it came out. I couldn't get out from under my old car for so long. Anyways, the problem I'm having is, is that it's jolting when it down shifts into 2nd gear. I just started it up drove out of the driveway about 50yrd. Hit the brakes and it started. Plus I had a 6 inch lift put on it with 35s and was wandering if I voided my warranty

[CadillacLuke24]

What kind of jolt? How hard is it?

 

Do you notice anything amiss underneath the truck?

[Cake]

It's hard enough to through you forward.

[Stevens03]

If you just had the lift put on, I'd be talking with them to see if there's something not done right. It could also be the slip yoke causing the bang/bump your feeling. And yes, by installing the lift, what driveline warranty you had left is gone.

[Cake]

It drove fine for two weeks. It was also driving fine when I parked it last. It just randomly started yesterday. I'm afraid to drive and make it worse. This blows.