2013 Sierra Rear End Shimmy

hotrodz37 · December 2, 2013

Hi all,

Long time looker, first time poster. I purchased a 2013 Sierra 1500 crew cab 2wd with the 5.3L and 3.42 gears and the z60 package back in August. Since day one I have been chasing down a rear end shimmy. I thought it might be all wheel and tire related and the dealer worked with me on the tires. I have done a ton of research here on the forum and a lot of vibration issues seem to have come down to the Goodyear Eagle LS2's 275-55-20. The dealer found one out of round tire and replaced. Vibration seemed to be a little better at higher speeds but still wasn't gone. I decided it was time to ditch the Goodyears and try something else since others have had good results with swapping out the tires. I was lucky enough to work through Discount Tire and they got a warranty claim with Goodyear and wound up buying all of the Goodyears back and just charged me the difference between the tires I had and the Tires I wanted. I wound up with the Cooper Discoverer ATP 275-60-20 which I know is a more aggressive all terrain tire but still built better than the OEM Goodyears. Well, after driving it 100 miles or so, the rear end shimmy is still there. It doesn't feel like a balance issue at all and the rear tires hardly took any weight on the road force balancer.

This shimmy seems to be more prevalent under 50mph and on different road surfaces, concrete roads it seems mostly smooth. All felt in the seats and none in the steering wheel. I can look over and see the passenger seat vibrating and seat belt buckle vibrating as well.

I had the truck jacked up on stands and put it 1st gear to get the tires rolling with my father and it looked like the drive shaft had a bit of runout in it. So basically my question is, is it not uncommon to have a driveshaft out of balance on a brand new truck?

I would love to hear y'all's thoughts and opinions on what this issue might be, other than wheels and tires (or if you still think it might be a tire and wheel issue).

Thanks in advance for your help!

hotrodz37 · December 16, 2013

I'm going to work with the dealer to try and get it solved. I doubt it is the tires if I have been through two sets and it still does it. Hopefully it is the shaft so I can get back to enjoying my truck. It has been a nightmare to drive over 70mph since day one.

gmtech4 · December 4, 2013

please tell me you're not gonna pay to have the shaft checked ,,,,get the gneral to put a new one on ,,,

get regional /district manager involved ,,,,you dont have to do this on your nickel

efritz · December 3, 2013

A driveshaft with runout will feel like you are on a vibrating chair, not a shimmy. It happens under 50 usually? sounds more suspension related to me. I have noticed these trucks are jittery on rough roads naturally, as they are stiff in the rear. Put lots of weight in the bed and see if it continues.

hotrodz37 · December 3, 2013

Thanks for the reply efritz I greatly appreciate it! I am leaning towards this as well since its intensity varies on different road surfaces. It might not hurt to have the drive shaft checked as well since as stated before it looked like it had some runout in it when I jacked it up on the stands.

Keep the ideas comin, thanks again!