Highway speed vibration on 2020?

[MrGraff]

Mine had vibrations when I bought it... drove it home 550 miles.  Next day drove down to my local tire shop and put brand new Michelin LTX AT2s on and its been butter every since.  Most good tire shops will give you a decent return on nearly new tires so its a win win to me.  Spend 70-80k on a truck and complain about tires, or spend 70-80k and replace the crap stockers and go on down the road.

[Bhop56]

Just bought 2020 3500 DRW diesel to pull my RV. I had "shimy/shake" vibration from day one. Came with Michelin tires. Turned out the truck needed two tires rebalanced (one big time), tires needed inflated to specs, and front end alignment. Took two trips to the dealer. Came off the delivery truck like that. You'd think for $70K you might get some QA at the GM factory. Currently have door ajar light on, driver cannot roll windows down, interior dome lights don't come on when door opened. Window lock not working. Going to have dealer also look at this Friday. No doubt a window motor, harness issue, body modulator or something. If Toyota made these type of heavy trucks, I would not think twice about buying one. GM is not too big to fail as far as I'm concerned. Keep it up GM and go out of business. Last one to leave in Flint Mich. be sure to turn the lights out.

[Dnt]

This is on Google Map when you look up the old closed down Mitsubishi plant in Normal Illinois. The last guys to leave apparently had access to a forklift and some empty parts racks and of course a sense of humor. Maybe the last ones out at GM will do something like this Haha

We can all buy a Rivian Electric truck maybe? 

 

 

Rivian quietly brings former Mitsubishi plant back to life

 

[Patrick McClain]

I have a 2020 Chevy HD. LTZ with the magna steering option. Bought new in Sept. 2019. Been in the dealer now 6 times for steering wheel shake at hwy. speeds and rattle like vibration in the steering wheel. Dealer has done 2 alignments. 2 software upgrades multiple force balance and still have not corrected this issue. Going back this week. GM TAC is involved. They can’t repair it. Drove a new High country last time with the service manager and it had the same problem. So it’s still an issue. 

[Patrick McClain]

After last repair seems to be doing it at lower speeds now. WTH!! Anyone else seeing this? 
lots of vibration in the steering wheel on curves and bumps. 

[gSwift]

6 minutes ago, Patrick McClain said:

After last repair seems to be doing it at lower speeds now. WTH!! Anyone else seeing this? 
lots of vibration in the steering wheel on curves and bumps. 

Last week I had a pretty bad vibration on my 2500 AT4 from about 67mph to 80. They road force balanced them and now the truck is happy. Hopefully they get yours fixed, but if not, it may be time to start talking with someone about a potential buy back.

[MTU Alum]

If it is at low speeds it is more a function of the steering software update and dealer not following the procedure.  A lot of them have not been clearing the offsets in software history after the reflash.  

 

#iworkforGM 

[Patrick McClain]

After the last reflash it’s more noticeable at 40 mph and up. It’s weird. GM is basically saying it’s road conditions now. Funny that my 2016 HD didn’t react this way to the same road conditions. I must say the Dealer is “trying’” to fix it though. 

[JC429]

Purchased a 2020 GMC 2.7L sierra two months ago and I noticed on highway speed 70+ mph the truck will shake.  Took it to the dealer where they performed a road force balance on the tires and told me it was fixed.  Just drove it this morning on the highway to work and I still feel it. 

 

[KARNUT]

It could be tires. My wife’s car is tire sensitive. The original tires got loud and vibrating at 30K miles. I replaced and at 20K they started doing the same. Most people would have done an alignment. With the ties being rotated every 4K miles with oil changes, there was no uneven wear. Discount tire agreed and gave me a pro rated change. The next set went almost 60K with no problem. I can hear the new set starting to sing. That was all over ten years of ownership. I do notice with all my vehicles road surfaces can effect a vehicles drivability. Especially if heavy trucks frequent the road. There one road that appears smooth. With heavy trucks frequently using it. There’s tiny ripples all along it. It’s noisy and vibrates. I could make a person think there’s a problem with their vehicle. You can see the imperfections in the rain. It not uncommon for people to pull over and check out their vehicle.


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[ShotgunZ71]

22 hours ago, KARNUT said:

It could be tires. My wife’s car is tire sensitive. The original tires got loud and vibrating at 30K miles. I replaced and at 20K they started doing the same. Most people would have done an alignment. With the ties being rotated every 4K miles with oil changes, there was no uneven wear. Discount tire agreed and gave me a pro rated change. The next set went almost 60K with no problem. I can hear the new set starting to sing. That was all over ten years of ownership. I do notice with all my vehicles road surfaces can effect a vehicles drivability. Especially if heavy trucks frequent the road. There one road that appears smooth. With heavy trucks frequently using it. There’s tiny ripples all along it. It’s noisy and vibrates. I could make a person think there’s a problem with their vehicle. You can see the imperfections in the rain. It not uncommon for people to pull over and check out their vehicle.


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Agreed. Many times, you can see the ripples on the highway. Just a slight variation in color/shadow on the road is the ripples. I’ve found that concrete highways are the smoothest, but are more expensive and slower to build. Most asphalt highways with a lot of use are repaved every few years. Interstates that are asphalt don’t last long at all.

[dwchapmanjr]

On 9/1/2020 at 6:30 PM, Patrick McClain said:

I must say the Dealer is “trying’” to fix it though. 

Have them run a picoscope on it to confirm the source of the issue.  Sounds like they're just taking stabs in the dark on the usual suspects.

[Patrick McClain]

They have ran several picoscopes to my understanding. They (GM) actually wrote a new calibration For the vehicle that did seem to help the shake problem. I’m thinking this Truck has a BCM issue. The other morning I came out to a dead vehicle. Had to jump it off. Drove it to the dealer. It had multiple codes in it. Steering shake came back on th trip to the dealer. Then after the codes were cleared it seemed to be fine. They replaced the battery per my request so at least something would be done. Weird thing too is that all of my engine hours got cleared out. Trip reset to the vehicle miles. Strange!!  Anyway I’m done with it. Going to replace it. 

[flyingfool]

I think alot of vibrations are  being blamed on the trucks, when in actuallity it's the paved road surface.  we have a fairly long wheelbase and depending on the paver wheel base used to smooth the roads, we might be syncing up with the  sin wave created by the paver or long tracker trailers that deformed the surface..

 

i prrooved my theory this weekend by visiting a local dry lake in the area El MIrage California, completly flat , no woops or undulations.  my vibration occurs at 78mph and carries on towards 100+mph on paved highways..  on the dry lake  i held the same speed range til i hit engine kill speed 105mph and absolutly ZERO vibrations!!!

 

its not the wheels or anything else

Edited September 27, 2020 by flyingfool

[dwchapmanjr]

59 minutes ago, Patrick McClain said:

They have ran several picoscopes to my understanding. They (GM) actually wrote a new calibration For the vehicle that did seem to help the shake problem. I’m thinking this Truck has a BCM issue. The other morning I came out to a dead vehicle. Had to jump it off. Drove it to the dealer. It had multiple codes in it. Steering shake came back on th trip to the dealer. Then after the codes were cleared it seemed to be fine. They replaced the battery per my request so at least something would be done. Weird thing too is that all of my engine hours got cleared out. Trip reset to the vehicle miles. Strange!!  Anyway I’m done with it. Going to replace it. 

I'd ask to see them.  Picoscope should hopefully be fairly clear as to the source of the vibrations or classification of it. (Is it aligned with tires, prop shaft or engine rpm and which order). Its rarely used and voided so they may not be too familiar with it.

 

Sounds like electrical or BCM related but yes after a battery dies or truck loses power it will have quite a few codes and may ride differently for a while as it needs to relearn some of the drive characteristics.  I'd expect most of the codes to be "communication lost" codes with the BCM since many systems connect to BCM.

 

Engine hour cleared out is a common issue when power is lost as that's stored in the instrument cluster control module and doesn't always persist loss of power.