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Posted

Well reading all these replies about vibration problems I will just live with it! Doesnt seem to effect anything mechanical except the tach will shutter when the vibration gets steady. I’m planning to install a 6 inch suspension lift & 35 K02’s. Maybe I will fix the issue while I’m in there?

Posted

Axles replaced with yukon axles last week. The 40-45mph vibration is gone but the 75mph or so vibration is still there. Maybe not as bad but its definitely still there. 

Posted

Well temperatures are above 0c here now finally so my vibration is back for the summer. I have noticed on our windy highways that sometimes it will be shaking then as you go around a sharp corner and straighten out the shaking will stop until the next turn. This is leading me back to the rear axle faces, like they shake when (the warp) is in sync, then as the one axle travels further than the other they find a point of balance momentarily before shaking my brain against my skull again. I never noticed it much in the winter months as either the body mounts and shock oil was stiffer than in the summer heat. Combination of shock oil, body mounts and a slightly out of spec axle face causing it all? I will try to source some axles from a wrecking yard and try it out. Hopefully I can get it dampened without putting any money into this junker. 

Posted

Mine has 75k on it. It started shaking around 30k and has gotten progressively worse over the last 45k. I’ve gotten both sets of my AT LT tires road force balanced, 1 set on stock wheels, another on aftermarket (I use hub centric rings). I thought maybe the new coopers I got were the issue because they’re “blems”. But I put my Toyo’s back on and it still shakes. Also have a leveling kit. Shop and myself checked everything out in front end thoroughly. Nothing loose, no ripped boots, no traces of grease. 

 

I can add in that I wrecked at 27k and repairs included a full frame replacement. So the rebuild could also be a cause.  I’m lost. 

Posted

New guy here, I have been reading this thread for a few days. I just bought a cherry 2015 with 27k and after a long highway drive I was like WTF. My console going crazy, SHAKING the hell out of the drinks and keys and what not. It starts about 68mph and gets worse to a peak of 75mph and reduces till about 83mph. Even coasting in neutral from 80 down to 70 it still shook so it appears to be in the rear end/driveline.

I would also come and go a bit. Hit a bump and shake away.

 

Well after reading I tried the simple solutions in this order and experienced a large reduction in the shake.

 

1. Road forced balanced the tires, I had just put new tires on it as well.

2. Leaf spring clamps from Autozone.

 

With the truck on lift, I placed the clamps behind the rear axle just at the point where the leafs started to gap a few millimeters. Tightened them down and then lowered truck to ground. Since the spring gap was slightly compressed now, I tightened the clamps a few more turns, effectively locking all three springs together. You do not want to go too far back because then you will run into binding as the suspension compresses and then rebounds.

 

Went driving....by my "seat of the pants" measuring tool, you can feel the reduction in the shake, and my drinks, while still exhibiting ripples, are MUCH better. It is bearable now for a very modest effort.

 

I definitely feel the issue is a resonance - the system of rotating parts working together at that range of speeds and allowing the frequency to transfer to the cab/etc. The springs themselves have a resonant frequency and by clamping them you are changing that frequency in the same way that a guitar string when fingered shorter now plays a higher note. Plus the added stability of a second clamp point and less wiggle between the springs.

 

I may consider shocks although that seems weird to me in this particular situation.

Posted

I have to confess that I seem to have solved my issue as well.  I have the 22" wheels and Bridgestone tires.  After 4 balancings at the Chevy dealer, I went across the street to a GMC dealer that I had prior experience with.  He took me in back and showed me a huge pile of these tires that they had taken off other trucks, and told me that the tires were garbage.  Then he road-force balanced mine, and told me that 2 were barely in spec, and 2 were so far out they couldn't be balanced.  So I paid for 2 new tires, which did not fix the problem, but it was better.  After a couple of months, though, it was just as bad.  I think these tires just fall apart internally.  So I bought a brand new set of 20" wheels, a take-off from a Yukon Denali, with Conti tires, and installed them.  And the shaking is gone.  Between the multiple trips to the dealer for balancing, the replacement tires, and the new tire and wheel set, I have spent at least $2500 trying to fix this.  GM has not really provided any help beyond paying for one of the balancing sessions.  This has been incredibly disappointing, but at least it is over.  Maybe....

  • Like 1
Posted
12 hours ago, theraptur said:

New guy here, I have been reading this thread for a few days. I just bought a cherry 2015 with 27k and after a long highway drive I was like WTF. My console going crazy, SHAKING the hell out of the drinks and keys and what not. It starts about 68mph and gets worse to a peak of 75mph and reduces till about 83mph. Even coasting in neutral from 80 down to 70 it still shook so it appears to be in the rear end/driveline.

I would also come and go a bit. Hit a bump and shake away.

 

Well after reading I tried the simple solutions in this order and experienced a large reduction in the shake.

 

1. Road forced balanced the tires, I had just put new tires on it as well.

2. Leaf spring clamps from Autozone.

 

With the truck on lift, I placed the clamps behind the rear axle just at the point where the leafs started to gap a few millimeters. Tightened them down and then lowered truck to ground. Since the spring gap was slightly compressed now, I tightened the clamps a few more turns, effectively locking all three springs together. You do not want to go too far back because then you will run into binding as the suspension compresses and then rebounds.

 

Went driving....by my "seat of the pants" measuring tool, you can feel the reduction in the shake, and my drinks, while still exhibiting ripples, are MUCH better. It is bearable now for a very modest effort.

 

I definitely feel the issue is a resonance - the system of rotating parts working together at that range of speeds and allowing the frequency to transfer to the cab/etc. The springs themselves have a resonant frequency and by clamping them you are changing that frequency in the same way that a guitar string when fingered shorter now plays a higher note. Plus the added stability of a second clamp point and less wiggle between the springs.

 

I may consider shocks although that seems weird to me in this particular situation.

If you like try the clamps about 4 inches in front of the rear axle. I tried the clamps on mine behind the axle and the ride was worst. Have had the clamp in front of the axle for 30k miles.

Posted
12 minutes ago, Colossus said:

Sounds promising, Mike. 

Hoping it stays.  My service guy (the honest GMC guy) swore to me that the Bridgestone tires were the problem, and that I should replace them with Michelins.  But if I did that, I would be sending the nice new tires along with the truck when the lease was up.  We'll see.  Not all of these problems are on trucks with 22" wheels and Bridgestones....  But mine seems OK for the moment.

Posted (edited)

What's going on guys.   Been doing a lot of reading about the vibration issues on these trucks.  Mine seems to be a little different than the "chevy shake" that a lot of guys have.  I've got a 15 Denali 6.2 8 speed that I bought last October, it currently has 48,000 miles on it.  Immediately upon buying it I noticed some terrible vibration and bumps through the wheel that I knew were not normal (this is my 5th GM Truck).  Naturally I started researching on the various forums and found plenty of threads and suggestions.  The problem is most of the suggestions seem to be for a constant vibration at a certain speed or situation.  My issue is a pretty short but intense vibration through the wheel that rattles the dash and surrounding area, but most times doesn't seem to make the entire truck vibrate or shake.  It's most intense between 45-55 mph but I can feel shaking though the wheel at other speeds too.  The strangest part of the issue though is that after I first bought the truck and noticed the problem, it suddenly went away after a few weeks (honestly I can't remember how long it was, but it was sometime when the weather started getting colder.)  So I hadn't had the issue in about 3 months and then driving home from work yesterday, BOOM there it was again.  Doesn't make much sense to me...  I've seen some mentions of guys having the power steering bushings replaced under TSB, other guys mention the hydraulic body mounts could be causing it???  I don't know but I figured this is a good place to start as I'm sure some of you guys have actually read all 800 pages of this thread and maybe can make some suggestions or most likely culprits.

 

It's really pissing me off because it makes it frustrating as hell to drive, and I love the truck but if this keeps up I won't be able to keep it.

 

Here's a pic of her.

20180328_100259.jpg

Edited by Scott Campbell
Posted

Torque Converter;  had the same problem around 32,000 miles.  There’s an SB out on it.  Dealer did the service.  No problem since.

  • Like 1
Posted

OK, filed with BBB last Friday and have a case number, now I am to send in any and all supporting documentation

within 10 days.  BBB has 40 days total that also is binding to GM.  Got a call yesterday from a GM rep in Texas.

He asked ordinary questions as to buy new,  current miles, dealer bought from, what dealer I took to about the

shake and vibration problems, etc.  Have paperwork from 5 trips (2 Chev dealer, 2 another Chev dealer, and 1 to GMC dealer).

GM rep will call back May 8th after gathering info from all the service departments. 

BTW, I bought a like new 4000 mile complete set of 18's (from 2016 Tahoe) with GY Assurance to do my own troubleshooting

and probably made ride 10% better (taller sidewalls).  Problem still exists!

 

A few pages back someone got $$$$$ and kept his truck.  Never found out the bottom line on that settlement.

 

SO stay tuned.......

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