Jed Blanks

This is an interesting post from Corvette Forum where a Chevy Engineer says vibration can be ring gear in differential and its common in trucks... http://www.corvetteforum.com/forums/c7-z06-discussion/3882807-c7-z06-engine-loping-2.html#post1593159405

Hmm. Ok. So 10%. Of 8200 is 820. But then wouldn't the 90/10 rule also apply to the number of real world people with this vibration vs the number of people that post here, Heck lets go ahead and say 1 out of 100 people with the problem post here. That gets us to what? 82000 issues? And based on the efforts of those offered replacement trucks, it sounds like 90% vibrate. It usually takes 5-10 before they find one that doesn't. How many did they make? 800,000?

I just want to say that my 2015 Denali vibrated stock. The vibration always felt like it was coming from the passenger front tire. It vibrated after balancing tires. After rotating the tires to put max RFV max on back tires and min at front passenger. It vibrated after a 2 in lift / level kit in the front (with sensor adjustments to compensate for added distance between sensor and angled upper a-arm) It got a little better after I added leaf spring clamps in front of the axle. But in order for them to work without interfering with sensors, it had to be too far forward and lowered the rear of the truck a little. It still vibrated after and alignment done by independent shop. It still vibrated after I added a 2.5 inch add-a leaf (with sensor adjustment to compensate for added distance between frame and bracket on axle) It vibrated after I reinstalled the leaf spring clamps to the rear of the axle but closer than before when I put them in the front. The rear of the truck lowered about .5 inch (lift was now 2inches) and vibration was maybe a little better. It vibrated after I got a second alignment. It got a lot better when I started tweaking the toe-in to spec myself using the front tie rods and a tape measure. It has almost completely stopped vibrating when I got a third alignment where they adjusted the caster and camber on the passenger's side. Sometimes it comes back though. So we shall see. Today the temp was above 50 degrees. The truck seems much tighter/rougher below 40 degrees. Also I'd like to say that I can't believe this thread is 552 pages with over 8000 posts. That is an incredible problem that GM has with these trucks.

A few days (weeks?) back I tried some rear spring clamps to help alleviate the issue. It helped, but only temporarily. The shake came back once the springs settled (30 miles?) Today I tried a large clamp (Autozone - 6 inch? $3) about 5 inches from the front of the driveshaft. I put the screw clamp opposite the large counterweight on drive shaft. Could be in my head but seems to have helped significantly. Going to continue down this path to see where it leads. http://www.demandaam.com/technical-support/aam-technical-tips/driveshaft-balancing

No. If anything the Denali magneride is worse. Every vibration has and equal and opposite vibration?

I have a 2 inch block under mine. Math says downward movement of connection point to control arm is 1 inch x 1.5/5 = 0.3 inches Leaving room for fudge factors, your control rod should be 3/16-3/8 longer. Or the connected point extended that far up by bracket. 1 inch because lift block is 1 inch thick 5 inch because lift block is half way and control arm is 10 inches 1.5 inches because sensor connector point is at 1.5-2 inches from frame. Unfortunately I arrived at the above length through trial and error instead of calculation. I started with 1" longer rod. Ride was smooth at slow speeds, but sloppy on corners and jittery at speed. I slowly lowered the length to 7/8 then 3/4 inches longer. Ride did not change significantly. No errors either. Just jittery at speed. I went back to stock length and ride was not terrible. Pretty good at speed but harsh around town. So now I'm looking at 3/16 - 3/8 inches longer than stock. 3/8 was still a little jittery. So I'm trying 3/16. Cliff notes: stock rods will work. Maybe a little longer needed but nowhere near 1".

hose clamps on driveshaft? Just in random spots or how do you decide where/what orientation?

merry Christmas to you as well Has anyone with shakes lifted the rear wheels off the ground and run the vehicle to see if rear wheels/rear end/ driveshaft shake? It's strange because it's perfectly smooth at speeds below 20. Like parking lots and such.

My 2015 Sierra Denali 2wd crew Shakes and bounces. It doesn't vibrate. It's. Not constant, it's random. It does it on smooth roads. I think posters should clarify what they have. There are those talking of vibration frequency. Subwoofer vibrates. my truck shakes or bounces. Am I in the wrong discussion?