Drivetrain shudder issues

[Reegs]

Hello new to forum. Just purchased. A 2013 Silverado ltz 4wd with a 5.3 and the 6 spd auto. I brought it home and noticed a shudder around 30-40 mph and slightly noticeable above that speed and more noticeAble going up hill at 30-40. When I punch it, it will go away. I feel like it more when trans is warm.

The dealer gave me two new tires and balanced all 4 but it still does it.

I noticed on driveshaft it looks like a weight fell off. Perfect rectangle with no paint, would this cause This.

I've read lots of articles about this in the newer models and wonder if anyone has nailed it down to any one thing.

Truck has 73k on it I still have some time on warranty, dealer told me to drive it more and maybe I'll get used to driving a6 spd but doesn't seem right

Any help?

[anumber1]

I would say you found the problem.

[ifixedit]

Yes, have them look at the driveshaft as they are balanced, and if the weight fell off it would likely be the cause of the problem. Wouldn't hurt to check out the u-joints at the same time.

[Reegs]

Ok thanks I'll be calling dealer

Hope that's it.