Feels like I am driving over rumble strips.

[LT1ZOB]

It’s GM’s 8speed auto TC curse. On Corvettes and Camaros, they call for a reprogram and a triple flush. I’m new to the truck world, I’m assuming the same procedure on the 8speeds applies here.

 

[dbbd1]

A different animal altogether...

On my '99 Ram pickup, it was the TC (and they upped the line pressure a bit). It would happen right about 45-50, as it was going into lockup.

 

[fozzi58]

Drive it. If you are handing it back then who cares if you make the damage worse. Just tell them the issues when you return it so one of us don't accidentally end up with it!

 

[Tonyrodz]

Drive it. If you are handing it back then who cares if you make the damage worse. Just tell them the issues when you return it so one of us don't accidentally end up with it!

I don't think I'd tell them.

 

[bigblackdog]

So I still have my Denali for one more month and am using it for odd and end jobs.
The thing I noticed over the post several months, which is getting predominantly worse, is it feels like I am driving over rumble strips. Like the ones they have in the middle of the road to keep you from crossing the yellow line.

I know it is not the AFM, because it did it during my TCM tune with AFM turned off. And it does it when in manual 7 mode now without the tune.

Could this be the driveshaft vibration I have read about? I would hate for the tranny to go down right before lease end. However with the powertrain warranty, I am assuming this wouldn't be my problem if it did. ???

If you have large performance tires 20's, 22's, the obnoxious 24's or larger, look at the tread on the inner part of the front tire. Run your hand along the tread at the inboard shoulder and see if you feel repetitive cupping or scalloping. This is usually due to tired shocks and misalignment. If you truly only have this for another month, fixing it won't save you a dime, unless its a lease with a low mileage buyback. Otherwise, drive on and let the new owner take some pride in his ride and fix it.
Best guess.

 

[Rocket Man]

Check for dried mud on the inside of your wheels.

Not everyone is trying to drive through rivers!

 

[bladenbullet]

shutter as youre settling in on a speed does sound like a torque converter concern...although there are other possibilities...a driveshaft will generally vibrate a very low speeds as it is turning at 3+ times the speed of the wheels...might want to try resting your foot on the brake lightly to switch off the torque converter and see if that makes a difference also...

if its programming its a pretty easy and cost effective fix...might want to get it checked....

 

[JumboShrimp]

Its a known problem - 'Smooth Road Rumble' (later just renamed to 'The Chevy Shake')
I had my '17 Tahoe to 3 dealers - rotated & balanced tires - no Help. Tried to blame it on 22" rims
New Torque Converter - No Help
Recently changed Steering Rack bushings and it helped a little but it still shows up from time to time.
There's an EXTENSIVE TSB on it - I'll try to find it and post it.
I'm related to some GM engineers and they were working hard to fix it but it is in ALL trucks built on that platform and it ain't going away.
Edit...
I joined this forum to get more info on the issue. There's LOTS of Rumbl'n trucks out there!!

 

[VDV18]

You don't want to spend money on it but are concerned enough to consider not driving it. Why aren't you taking it in for the TSB that's free?

 

[PJS3]

Its a known problem - 'Smooth Road Rumble' (later just renamed to 'The Chevy Shake')
I had my '17 Tahoe to 3 dealers - rotated & balanced tires - no Help. Tried to blame it on 22" rims
New Torque Converter - No Help
Recently changed Steering Rack bushings and it helped a little but it still shows up from time to time.
There's an EXTENSIVE TSB on it - I'll try to find it and post it.
I'm related to some GM engineers and they were working hard to fix it but it is in ALL trucks built on that platform and it ain't going away.
Edit...
I joined this forum to get more info on the issue. There's LOTS of Rumbl'n trucks out there!!

Wow... I'm having this issue with my '16 LTZ with barely 17K on it. Stock, chrome 22" wheels with pretty fresh Continental Crosscontact LX20 tires. The crap is freakin' ANNOYING!!!! Once I hit 80mph or higher the vehicle feels like it's 20 years old trying to do 100mph. Vibration alllllll through the suspension and steering wheel and seats! Just plain rough ride! Had the tires re-balanced once, road balanced again.... Same outcome. I even lowered the tire pressure to 33psi all around... THAT got me a placebo effect solution at best.... I'm VERY interested to know if there is a TSB fix on this! Please do follow through with your proposal to find and post it.