Shake or Vibration Issues

[paxtonman]

So let me "set" this straight. The 3rd truck vibrates when you go over 70 MPH. I did not drive it to an interstate where I could maintain this speed during the test drive. The other 2 vibrate starting around 40 to 50 mph. I do have faith that my dealer will get the problem repaired. So far they have not let me down. We purchase a lot of vehicles from them and use the service department religiously. I have 24 GM vehicles to maintain and have found them to be more honest than any of the independents we have tried. It also doesn't hurt that I bought a truck that had sold for $44K 13 months ago and I paid $30K for it with 7,900 miles on it and was given all the factory warranty back. So for that, I can deal with them working to fix the problem that was created by a GM supplier. They also give me what ever I want to drive when it's there with the exception of a Z06, Z28,ZL1 or CTS-V. And if anyone is interested the dealer is Bradshaw Automotive in Greer,SC.

 

You think after three years with no solution for the vibrators your problem is going to be fixed by your dealer? Go back to page one and start reading, good luck. The new GM has one goal and one goal only, PROFIT, nothing else matters.

[BootyHunter86]

 

You think after three years with no solution for the vibrators your problem is going to be fixed by your dealer? Go back to page one and start reading, good luck. The new GM has one goal and one goal only, PROFIT, nothing else matters.

Pretty much.

 

 

Sent from my iPhone using Tapatalk

[tnchevy]

Hey, this guy is tight with his dealer so I am sure it will get fixed!

[Snoringbear]

"You think after three years with no solution for the vibrators your problem is going to be fixed by your dealer? Go back to page one and start reading, good luck. The new GM has one goal and one goal only, PROFIT, nothing else matters."

 

Well, after three years, it seems to me that 8,042 comments are not particularly excessive; especially if the 80/20 rule is applied which is 80% of these comments were probably made by 20% of the posters, probably less. Then, start a little factoring or slicing and dicing as the number crunchers say, by the numerous different theories what the root causes may be and then factor the numerous different modifications made that may have contributed to the problem, then the number (percent) of trucks becomes pretty small. So, it's easy to understand why GM hasn't put out a recall on "vibration". Just saying

[DALaws]

I just got off the phone with the dealer. He said he replaced all four tires and it now drives fine. I asked if he drove it and he said no! Let the games begin.

[ekimsinnigcm]

UPDATE: My truck has been in since 01/27/2016. Dealer ordered a replacement drive shaft (If you have been following a post I made earlier, I actually pulled my drive shaft and had it checked and balanced at a custom/performance drive shaft shop and it was basically spot on. They added a small slip for good measure but resulted in ZERO change to the vibration). The dealer replaced my driveshaft and I verified that it was replaced because I marked my original one. That did not rectify the issue. The dealer had a set of OEM take off 18's w/ Goodyears and installed them on my work truck that has the base steel gray 17's on Bridgestones. They called to inform me the truck was ready to be picked up (02/12/16) and they had a surprise for me! They informed me that had upgraded me to the 18s at no cost to me and the vibration was gone. I arrived at the dealership (Chevrolet of Wesley Chapel FL) and spoke with Marty (awesome guy BTW) and we talked for a few minutes and then I went on my way. I tested the truck on the interstate immediately after picking the truck up and the vibration was now worse than before. I immediately called Marty and let him know that we still had a vibration and I promptly returned the truck and was back in my loaner (that vibrates too) within a few minutes. This is my 3rd visit unfortunately and my vehicle has been in the Service Center for more than 15 days but at this time less than 30. I do qualify to submit for a final repair from GM, but I'd really hate to go this route as the truck looks great as we all know but we literally cant "shake" the vibration at this time. I can't say enough great things about my dealer though. They have been testing, testing, and more testing and keeping me updated throughout the process. I really feel bad for everyone who has a dealer that says this issue is "normal" or "within spec". If you are having that issue, I strongly advise finding another dealer willing to provide the level of service you/we as customer(s) deserve.

 

Another reason I'm really hoping it does not come to Lemon Law/BBB/Arbitration/BuyBack/Repurchase is because I had the work truck front and rear bumpers,grille,bumper cover between grille and bumper, headlight trim, mirrors and door handles all color matched and the truck tinted. The truck looks stunning! I'd hate to think I would be out all of the $$$ I put into having this work done.

[abominable z71]

Ran across an interesting article on tire balancing that I thought I would share with you all. It was talking about how important a very good balance it today, in light of the fact that not only are vehicles much stiffer and hence transmit vibration and road noise more, but with larger diameter wheels the unsparing weight has shot up dramatically and that increases road harshness. Plus, lower profile tires have less sidewall to absorb the vibration and road hardness. So far...duhhh. Like we didn't know that.

 

But what was interesting was they talked about balancing. Yes, Road Force Variation measurements are important to address as best as possible with the particular wheel and tire combination. But the pointed out something I hadn't even thought of. Most modern wheel balances do what is called dynamic balance, which is of course the better balancing technique. It's what we do on all large turbo machinery, including big compressors and turbines. (30,000 hp and more!). But they were saying that with wider and wider wheels and tires, sometimes what balances out perfectly dynamically will leave a significant residual static unbalance! WHOA! Hold the boat. That's a new one on me. Now, I haven't got my head around that notion, and I'm not sure m fully bought in to it. But it would explain a shit-load if what we were seeing is wheels and tires that are being sent out on this super-sensitive trucks with even bit of excess static unbalance.

 

Here is my point. If any of you are in the middle of going through another round of tire RF at your dealer, and you have a good relationship with that dealer and they are willing to try something, ask them this: after they finish the RF force match (remember, it's not an RF balance!!), and they then f ish the routine dynamic balance, ask them to switch the balance machine to "static" balance mode and take a reading. Don't have to necessarily make any adjustments, but t would be interesting to get some static balance readings from some of these supposed "balanced" wheel/tire assemblies.

 

And report back here if you can.

I'm trying to wrap my head around this one. Not sure that I buy that an assembly or single part can be dynamically balanced but not statically balanced. I would believe the opposite before that. Did the article offer any form of evidence to support this mathematically or at least empirically? Parallel axis theorem doesn't support this claim, the CG for a solid body is the CG. But there are a few equations used in fluid mechanics that that we know work for calculations but are not proven or understood mathematically like the navier-stokes equations that are a millennium prize problem. This would be interesting to check though I'm going to ask Les Schwab if this is something they can do. Perform an RFB on the hunter then check the static if there is indeed a difference how do you fix it would be the million dollar question.

[mjb4450]

"You think after three years with no solution for the vibrators your problem is going to be fixed by your dealer? Go back to page one and start reading, good luck. The new GM has one goal and one goal only, PROFIT, nothing else matters."

 

Well, after three years, it seems to me that 8,042 comments are not particularly excessive; especially if the 80/20 rule is applied which is 80% of these comments were probably made by 20% of the posters, probably less. Then, start a little factoring or slicing and dicing as the number crunchers say, by the numerous different theories what the root causes may be and then factor the numerous different modifications made that may have contributed to the problem, then the number (percent) of trucks becomes pretty small. So, it's easy to understand why GM hasn't put out a recall on "vibration". Just saying

Now multiply the number of legitimate vibrations on this thread by the 99% of Silverado owners who don't know this Forum even exists and you'll have a figure more relevant.

[14SLTZ71]

I think many of us were "Brand Loyal" problem being the "Brand isn't Loyal" anymore.

Edited February 16, 2016 by 14LTZZ71

[southern_sierra]

Now multiply the number of legitimate vibrations on this thread by the 99% of Silverado owners who don't know this Forum even exists and you'll have a figure more relevant.

Same thing I was thinking. I asked my dealer over a year ago, had they had any trouble with these trucks Vibrating and he said, oh yea.

[Wrench589]

I'm trying to wrap my head around this one. Not sure that I buy that an assembly or single part can be dynamically balanced but not statically balanced. I would believe the opposite before that. Did the article offer any form of evidence to support this mathematically or at least empirically? Parallel axis theorem doesn't support this claim, the CG for a solid body is the CG. But there are a few equations used in fluid mechanics that that we know work for calculations but are not proven or understood mathematically like the navier-stokes equations that are a millennium prize problem. This would be interesting to check though I'm going to ask Les Schwab if this is something they can do. Perform an RFB on the hunter then check the static if there is indeed a difference how do you fix it would be the million dollar question.

Again, it's NOT a "Road Force Balance". It's a measurement of the Road Force Variation. And weights will NOT correct it. As I explained before, only indexing the tires on the wheels may potentially reduce it, if the wheels also have some RFV. If not, new tires is the on,y option.

 

After the RFV is checked/corrected is the mass balancing done, with weights for correction.

 

That said, I too am still thinking about this. I did some more reading and it looks like the science part is still sound - properly dynamically balanced will also be statically balanced. The problem is that most balance machines are set up with some kind of threshold of acceptance, where the if the residual dynamics unbalance is below it, the machine simply reports "0 correction required". This gives the false sense that the residual is 0 - but it's not. Still, not a big deal. Unless, the residual is more on one plane than the other. Or, they end up on the same side of the tire. Then, they add up to some unacceptable static unbalance. Looks like this is what the article was on about.

 

Now, I also found that at least one other tire balance machine manufacturers is advertising a feature on their high end models that has a special algorithm that optimizes the dynamic and static residual unbalance. They even take a pot-shot at their competitors that focus on weight reduction as part of this problem. Guess what.... Hunter advertises their machines have some kind of "weight optimizing" algorithm to ensure the least amount of weight is used and save the tire shop money over the course of the year!

 

Hmmm. Starting to see a problem here, maybe? Since all these trucks have been done on the Hunter GSP9700 (or the GM branded equivalent), I'm wondering if there may be something to this.

 

Like is said - next person to take your vehicle to the dealer for another round of Road Force and balance, ask them to measure the status unbalance after they are all done and report it to you.

 

First chance I get, I'm taking my 22's to a shop and have them checked.

[Snoringbear]

"Now multiply the number of legitimate vibrations on this thread by the 99% of Silverado owners who don't know this Forum even exists and you'll have a figure more relevant."

 

I understand your point. But, statistically that's not necessary. And, even if GM should be receptive to a recall which of the numerous hypothetical causes stated in this thread would you suggest?

[pm26]

Again, it's NOT a "Road Force Balance". It's a measurement of the Road Force Variation. And weights will NOT correct it. As I explained before, only indexing the tires on the wheels may potentially reduce it, if the wheels also have some RFV. If not, new tires is the on,y option.

 

After the RFV is checked/corrected is the mass balancing done, with weights for correction.

 

That said, I too am still thinking about this. I did some more reading and it looks like the science part is still sound - properly dynamically balanced will also be statically balanced. The problem is that most balance machines are set up with some kind of threshold of acceptance, where the if the residual dynamics unbalance is below it, the machine simply reports "0 correction required". This gives the false sense that the residual is 0 - but it's not. Still, not a big deal. Unless, the residual is more on one plane than the other. Or, they end up on the same side of the tire. Then, they add up to some unacceptable static unbalance. Looks like this is what the article was on about.

 

Now, I also found that at least one other tire balance machine manufacturers is advertising a feature on their high end models that has a special algorithm that optimizes the dynamic and static residual unbalance. They even take a pot-shot at their competitors that focus on weight reduction as part of this problem. Guess what.... Hunter advertises their machines have some kind of "weight optimizing" algorithm to ensure the least amount of weight is used and save the tire shop money over the course of the year!

 

Hmmm. Starting to see a problem here, maybe? Since all these trucks have been done on the Hunter GSP9700 (or the GM branded equivalent), I'm wondering if there may be something to this.

 

Like is said - next person to take your vehicle to the dealer for another round of Road Force and balance, ask them to measure the status unbalance after they are all done and report it to you.

 

First chance I get, I'm taking my 22's to a shop and have them checked.

There are certain variables that can have a very negative effect on proper balancing. Even though Hunter 9700 machine is a good machine, proper calibration and proper mounting of the wheel on the balancer is of utmost importance. Many places use only traditional cones to center the wheel on the balancer. For most alloy wheels, a cone is placed on the inside of the wheel, then a speed nut with a pressure cup with a rubber ring is tightened on the outside of the wheel. The biggest problem is that if wrong size cone is selected and the wheel has an inner lip in the center hole, sometimes the cone catches on the inner lip and the wheel will not be properly centered and balance will be off. You can do a quick sanity check to see if the wheel is properly mounted on the machine. After the weights are placed and the machine shows all zeros, then ask the technician to loosen the speed nut, rotate the wheel about 45 degrees and have them spin the wheel again. The wheel must be physically moved, merely loosening the speed nut and tightening it will not accomplish anything.

 

For chrome clad wheels, never use a centering cone on the outside of the wheel because it can catch on the cladding and cause the wheel to be improperly balanced.

 

The best way to balance the wheels is by using collets (short cones) and flange plates which hold the wheel by the lug nut holes. You will get most consistent balance this way. But how many places actually use such equipment. A good set of Haweka plates and collets costs at least $ 6k. A full set of good quality centering cones is a lot cheaper - about $ 500 plus about $ 200 for a good quality speed nut.

Edited February 16, 2016 by pm26

[mjb4450]

"Now multiply the number of legitimate vibrations on this thread by the 99% of Silverado owners who don't know this Forum even exists and you'll have a figure more relevant."

 

I understand your point. But, statistically that's not necessary. And, even if GM should be receptive to a recall which of the numerous hypothetical causes stated in this thread would you suggest?

I wouldn't suggest any of these proposed causes as a fix. It's obviously an engineering problem that will not be diagnosed by anyone here without extensive facilities, training, and money meaning this ball is squarely in GM's court. And as you pointed to, they don't seem to be all that interested in finding a fix. And why should they? People keep buying more even after they've been skunked repeatedly. I think the better question is how many customers with these problems are going to put their money with another company vs how many have the battered wife syndrome and will keep buying vibrator after vibrator after vibrator due to some bizzare belief that THEY owe GM loyalty. Bottom line is that there will be no fix until it costs GM enough in lost customers. All this endless thread does is go over the same ground and when someone new comes on with the vibration, the theories cycle over and over again.

[Snoringbear]

"Bottom line is that there will be no fix until it costs GM enough in lost customers. All this endless thread does is go over the same ground and when someone new comes on with the vibration, the theories cycle over and over again."

 

Agree about this endless thread. Some folks on this thread really know how to pound sand for sure. I went to the trouble to do a little googling about Ford and Ram. Found that they each have a blog with threads similar to this one. And, observed much the same mix of problems including vibration. So, what to do? Don't know. But, at the risk of being repetitive, I'll just say that there are way too many variables running through this thread to arrive at any conclusions especially when considering that a good number of the subject trucks have gone through after market tinkering and such. Then, it's also my perception that some of these posters may be first time truck buyers and just because they paid $40k ~ $50 or more they think it should ride like a car of similar value - which is unrealistic. You can dress up a truck to look like a prom queen but when you undress it you will still find a truck underneath. Probably not the greatest analogy but it's the best I can do, ha ha !!!