My 2007 H3 Hummer is having issues with the steering. I purchased the H3 from a dealership back in October of 2011. 22" crome rims were already installed on it. Until mid-January(13) everything was perfect. One of the tires went flat due to a crack in the wall of the tire. I had no other choice but to put one of the original tires and rims back on it. My very unintellegent self decided to keep driving it with the different sized rim and tire for about a month. The day that I was actually going to take the H3 to get the tire fixed, I encountered a problem when backing out of a parking stall. I turned my steering wheel to the right to back up and it felt as if the tire may have been rubbing against something. I had some of my co-workers check it out and they all said that the tires where not rubbing on anything. I immediatley drove it to the closest maintenence shop to figure out what is going on. They fixed the tire and then told me that they do not do maintenence on 4x4's. They suggested that there may be a technical issue in the vehicles computer system or it could be a drive shaft issue. Here are some exra details that may help you in figuring out what the problem may be. When driving straight, there seems to be no friction occuring. When I go to turn, it seems to tighten and almost makes the front end of the vehicle hop or skip. One of my co-workers checked the power steering fluid and it was a little low. He said that I could have a leak in the power steering lines and they could possibly contain some air. I obivsouly have no idea what it could be. Please feel free to ask me any questions about the situation to help you find an awnser. Thank you for your time.

 

I would check the transfercase. The H3 is AWD which means that all four tires have power to them all the time. Different sized tires ran on one corner could cause the the transfer case extra wear because it trying to keep up with the different rotation rates of the tire that is shorter. I have seen this explode transfer cases in Land Rovers from doing the same thing

 

Make sure you do not have 4 High Lock selected. If not, go through your selection options a few times to exercise the actuator motor. If that doesn't work, do a search, keyword Plastic Shift Fork. Good Luck.

 

1, if the outside diameter of the TIRE is the same it would not matter or affect anything. if different it would in long term over work the differential gears,still not a steering problem.

2, the steering problem sounds like the same one that comes up here about once a week, hi lock mode driving. when will we ever learn?