Shake or Vibration Issues

[Ewwa44]

 

The Picometer measures vibration in the truck. More than likely you will get a 3rd order vibration I believe it is.

What is a 3rd order vibration? I don't understand why they can't fix this crap.

Edited February 25, 2016 by Ewwa44

[Jesse Davidson]

What is a 3rd order vibration? I don't understand why they can't fix this crap.

I'm not too familiar with the order, but here is a post from a few pages back

 

No, it can't differentiate between rim or tire from a simple Road Force measurement. But, if the operator follows the instruction in Hunters manual, it can. Step one is to mount the bare wheel (no tire) on the machine and measure the bead runout is (inner and out). This is indexed to a reference (typically the valve stem). The roller is no used, of course, but the reality is, the stiffness of the wheel in likely going to be consistency all the way around.

Next, mount the tire.

Next, measure the Road Force Variation. By then comparing the results of the combined RFV to the wheel runout, the machine can determine if the final is tire or wheel, and where the tire should be rotated to relative to the wheel to minimize the total combined.

Here is the catch....if the wheel has 0 runout, then there is absolutely no opportunity to improve the combined total. Stuck with whatever the tire produces.

As for the machine itself, the roller arm does not take any measurements. It simply applies a force to the tire to deflect/load it similar to on a vehicle going down a road. I say similar because there are two fundamental differences that even Hunetr does not talk about. First, the roller is round, whilst the road is flat. There floor, the deflection pattern of he tread will be different. Second, the tire is spinning at a much lower speed than you are driving at. How much difference does that make, of what kind of errors could that result in? Don't know.

What the machine does measure is vibration of the main shaft. It measures it in two locations along the shaft, likely beside the bearings, and knowing the various distances of the machine and the tire/wheel, it can calculate out of balance at the selected correction planes. This information can also be used for the Road Force Variation calculations, based on a known load of the roller. The RF result is expressed in LB, and from what I understand, Hunter expresses it that way to relate it to the amount of shaking force that would be generated at a reference speed with much that RFV. One could back calculate that to an equivalent static unbalance, for example, to get a better feel for it and it would be in the oz's, as we are used to seeing it.

The specs on the Hunetr are relative to doing the dynamic balancing portion, but are related to the RF, as the same sensors are doing that too.

Back to your truck, if the peak vibration is tracking 3x tire speed, then it it not a resonance. That should come and go at the specific natural frequency. Now, many resonances do have a bandwidth associated with them, because of some damping in the system - does yours start at a speed, get worse to a peak, them diminish back to very low again? If so, that could be a resonance. If it just keeps getting higher and higher in amplitude as speed increases, that is usually simple mass unbalance.

[Jesse Davidson]

Ohh, I forgot to mention, I called and left a message with the attorney that I have been in contact with. Hope to know more soon.

[14SLTZ71]

OK, not trying to start an argument but I have to ask. With countless owners posting that their truck did not start vibrating until a few thousand miles after purchase, and all the owners who bought a second, even third truck only to discover that they also vibrated, and all the expense and hassle they went through, why would you a) take the risk and b) reward GM, who has known about this problem for three years, by buying another before a real permanent fix or re engineering is done? What am I missing with this blind loyalty?

 

Some people were offered trade in assistance towards the purchase of another GM truck and that's all GM would offer them. They weren't offered Buy-back and that's why some people are on their 2nd or even 3rd GM truck. When you finance and are stuck with payments sometimes you are at the mercy of the manufacture and have to take what you can get, unfortunately some of these guys keep ending up with another vibrator.

I was offered trade assistance towards a 2015 6.2L 4x4 Z71 and when it arrived it vibrated worse than my 2014. I drove 2 more on their lot, a 2015 Silverado and a 2015 GMC Sierra Denali and they both vibrated, so I gave up on GM and traded in for another brand. Lost my ass on the deal too because other dealerships are catching on that the GM trucks vibrate and they won't give you shit for trade in value.

Edited February 26, 2016 by 14LTZZ71

[Jesse Davidson]

 

Some people were offered trade in assistance towards the purchase of another GM truck and that's all GM would offer them. They weren't offered Buy-back and that's why some people are on their 2nd or even 3rd GM truck. When you finance and are stuck with payments sometimes you are at the mercy of the manufacture and have to take what you can get, unfortunately some of these guys keep ending up with another vibrator.

I was offered trade assistance towards a 2015 6.2L 4x4 Z71 and when it arrived it vibrated worse than my 2014. I drove 2 more on their lot, a 2015 Silverado and a 2015 GMC Sierra Denali and they both vibrated, so I gave up on GM and traded in for another brand. Lost my ass on the deal too because other dealerships are catching on that the GM trucks vibrate and they won't give you shit for trade in value.

Damn right.... couple months ago when I first started getting the problems and GM wouldn't do anything I went to a few dealers, was offered 32 and 35k for it... today I was offered 27..... truck is 8mo old with 8200mi on it...MSRP was about 62k

Edited February 26, 2016 by Jesse D

[pm26]

Damn right.... couple months ago when I first started getting the problems and GM wouldn't do anything I went to a few dealers, was offered 32 and 35k for it... today I was offered 27..... truck is 8mo old with 8200mi on it...MSRP was about 62k

Dollars or pesos?

[EastCoast HD]

Damn right.... couple months ago when I first started getting the problems and GM wouldn't do anything I went to a few dealers, was offered 32 and 35k for it... today I was offered 27..... truck is 8mo old with 8200mi on it...MSRP was about 62k

 

For an LT 4X4 Crewcab ???

[tnchevy]

My LT Z71 (probably not near as many options as Jesse's) stickered at $42,500 and I got it for about $32,000 or about 25% off sticker like many on here has. Those "good deals" are nice but they severely hurt resale value. All vehicles depreciate at least 20% right when you drive it off the lot so that would make the truck I paid $32k for be worth around $26k and when trading it in most dealers are of course going to offer me less than that but you can negotiate up some from that whatever they offer. When I was buying in late 2014 both Ford and Dodge dealerships I visited were pricing me around 20% off and if I was serious I am sure I could have got a few more percent off. IMO all of the full size trucks are way over priced and the deep discounts is just a way for the buyer to feel like they got a better deal.

[Jesse Davidson]

Dollars or pesos?

what do you think, I live in Boston MA

 

 

For an LT 4X4 Crewcab ???

yes, sticker was $46k, and I have about $13k in accessories and other options, plus a $3k 7yr b2b warranty from GM

 

EDIT: Actually that needs to go up a little, I forgot to add the cost of the spray in bedliner and the stock 18" wheels, so its really $63k with everything

My LT Z71 (probably not near as many options as Jesse's) stickered at $42,500 and I got it for about $32,000 or about 25% off sticker like many on here has. Those "good deals" are nice but they severely hurt resale value. All vehicles depreciate at least 20% right when you drive it off the lot so that would make the truck I paid $32k for be worth around $26k and when trading it in most dealers are of course going to offer me less than that but you can negotiate up some from that whatever they offer. When I was buying in late 2014 both Ford and Dodge dealerships I visited were pricing me around 20% off and if I was serious I am sure I could have got a few more percent off. IMO all of the full size trucks are way over priced and the deep discounts is just a way for the buyer to feel like they got a better deal.

completely agree with that sentiment, but even still... $27k is bull sh*t for this truck

Edited February 26, 2016 by Jesse D

[tnchevy]

Your right, it is BS. I have to take the better halfs Jeep GC in for yet another recall in the next week or two. I might mess with a salesman and see what kind of deal they are offering for a RAM and also what they will give me for trade in.

[Jesse Davidson]

The Sales manager came over to me yesterday and point blank asked if my truck had the "Chevy Shake".... best of luck

 

I had given up trying to work with my dealer after 4 visits, but I have now decided that I am just going to keep sending it in over and over and Force GM to spend money on it until something happens. I have no doubt that it won't be fixed, but maybe they will finally get the message that I'm not going to accept this... Like I mentioned, I called and left a message with the attorney yesterday afternoon. Hope to hear some good news today, If nothing has moved forward, I'm considering filing suit on my own. I'm done with this shit.

[Snoringbear]

I'm thinking that the Magnetic Ride Control feature (check out below URL) currently being offered on the Denali may be GM's solution to the vibration problem. 2016 is the second year for this feature. I'm guessing if it proves to be successful it will be rolled out to High Country, and LTZ in the next year or so. Perhaps on down to the LT as the cost drops. Anyway, seems interesting. Wish it was on my 2015 LTZ.

 

http://media.gm.com/media/us/en/gmc/news.detail.html/content/Pages/news/us/en/2014/Jun/0623-sierra-mrc.html

[Jesse Davidson]

I'm thinking that the Magnetic Ride Control feature (check out below URL) currently being offered on the Denali may be GM's solution to the vibration problem. 2016 is the second year for this feature. I'm guessing if it proves to be successful it will be rolled out to High Country, and LTZ in the next year or so. Perhaps on down to the LT as the cost drops. Anyway, seems interesting. Wish it was on my 2015 LTZ.

 

http://media.gm.com/media/us/en/gmc/news.detail.html/content/Pages/news/us/en/2014/Jun/0623-sierra-mrc.html

The Denali's still have the problem possibly just not as bad, idk but there are fewer of them on the road too. I have a few of them on my list for people who specifically asked to be part of the lawsuit

[pm26]

what do you think, I live in Boston MA

 

 

Just trying to inject a little humor into this already sad situation. Apparently not successfully.

 

Unfortunately accessories are not worth much when it comes to trading in a vehicle.

Edited February 26, 2016 by pm26

[Jesse Davidson]

Just trying to inject a little humor into this already sad situation. Apparently not successfully.

 

Unfortunately accessories are not worth much when it comes to trading in a vehicle.

The accessories were all on at time of purchase, I literally took the truck that was in the showroom. regardless of the fact that they depreciate just as the truck does, they still have value, and when they cost the amount that I have, it is still thousands of dollars.

 

Lets just pretend that I don't have any accessories or extended warranty, my MSRP was approximately $46,000 now take out the incentives of $6,250 and you have $39,750. now lets say you take out another $3,000 for a dealer discount, that leaves $36,750. so take off 20% and your left with $29,400... which is still more than the offer. KBB which is on the low side of values says $29,370 as an average.

 

The true value is according to NADA which is what dealers use when at the auction, and what insurance companies use when a vehicle is totaled... I used to have a dealers license, so I do know this..... NADA says clean trade, which is what mine would qualify for, is $32,775.

 

Again, this is without any of my accessories or extended warranty