2003 Avalanche

my husband bought this Avalanche,in2004 it only had 22000 miles on it. He only drives to and from work which is only about 10mi one way and few odd trips .It still has under28000 mi but the front end on the left you can feel bumps up to the steering wheel and your not driving over a bump. My son was a machanic in the Army and he has looked at it but doesn't see anything. He also says the truck has adjustble springs or somthing and they seem ok. He thinks it might be the tires and come to think of it, the last time I had the tires rotated is when seems like it started doing that. unless my husband ran into a curb or something I don't know about. Any opinions.

It is possible that a tire is out of balance.

It's also possible that a tire is damaged from a curb strike, a pothole, or is simply experiencing a carcass failure and/or slipping reinforcement belt. That happens frequently with Bridegestone/Firestone tires, and some Goodyear/Kelley tires.

The most likely cause of your concern is a slip/stick condition in the intermediate steering shaft, a common problem with these vehicles, the gm mandated repair is to use an updated grease kit to lubricate the steering
shaft.

The most likely cause of your concern is a slip/stick condition in the intermediate steering shaft, a common problem with these vehicles, the gm mandated repair is to use an updated grease kit to lubricate the steering
shaft.

Yep, They used to replace them and now just lube them. This has been a problem for a long time.