CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

The dancing truck

I have a 2005 Chevy Silverado Z71 4x4.When driving on the Arizona Hiways or dirt roads (which are about the same way) my truck does an Irish Jig when going over bumps,cracks or pot holes( which is worse). It makes it very hard to control when the truck on the hiway and so I’m Usally a wreck by the time I get to the destination. The Chevy mechanic said there is nothing wrong that he can see----Help!

Not knowing the actual conditions of the roads, its hard for me to judge. Three things come to mind.

  1. Are your tire pressure set properly? Tire pressure effectively change the “spring rate” of the tire wheel assy.
  2. Are you driving fast over the bumps? Most 4x4 trucks in my experience will will do this to some extent on rough roads at speed.
  3. Is the alignment within spec?

I assume your mechanic checked the ahocks, springs, and other suspension components and found nothing wrong.

I would suggest that you have a mechanic (possibly a different one) check the anti-sway bar(s) and the links associated with that component. A broken anti-sway bar or link will cause a vehicle to be very difficult to control at higher speeds.

Having been raised in a rural area with gravel roads and potholes, all pickups, especially one like yours, dance around to some extent. That’s because of the stiffer back springs you need for that carrying capacity.

As other say, get a different mechanic to look at it, check your tire pressuree, and sway bars, and SLOW DOWN. If you don’t use the truck for carrying heavy loads, use the minimum tire pressure specified on the door post.

Speaking of tires,
Do you have large tires on the truck ? They will have their own bounce potential un-controlable by any of the suspension. They can be bouncing at any and all diferent rates and directions.
Have you ever watched heavy equipment like front-end loaders and graders drive down the hiway ? The tires are their only suspension and you can really see the over-exageration of tire bounce on those things. To a lesser degree the big tires typical on many 4x4 trucks have bounce in them that you cannot control with shocks and springs and things.

My 2005 sliverado 1500 4x4 would bounce me all over the road. I finaly put some new shocks on it and it has helped, but it still rides like a truck… a little rough, but it is a regular cab and short bed. With out the new shocks I was all over the interstate when I ran across any rough spots.