Unstable over bumps

rmkmb · July 31, 2019

8 hours ago, econometrics said:

You're not alone, fellow Rancho victim. Lol

Hahaha,

good one .I guess I am too.

It feels like the shocks are too stiff and don't have time to dampen.

Interesting to see if a shock swap will help this situation

Stevejfy · July 31, 2019

My truck also bounces excessively. So much so that one time on I-70 near Denver I had to correct the sideways bounce of the truck. I can go to the rear bumper and bounce it up and down and when I release my hands from the bumper the truck will bounce 3+ times. I heard many years ago that if over 1 1/2 times you need new shocks. When i apply the brakes to a hard stop at 10 mph the truck bounces several times. I feel it is unsafe. My truck has 4000 miles on it, if it had 60000 I'd be replacing the shocks with heavy duty shocks. I have an appointment next week with a local dealer but have little faith that anything will come of it.

derek01f · August 1, 2019

13 hours ago, Stevejfy said:

My truck also bounces excessively. So much so that one time on I-70 near Denver I had to correct the sideways bounce of the truck. I can go to the rear bumper and bounce it up and down and when I release my hands from the bumper the truck will bounce 3+ times. I heard many years ago that if over 1 1/2 times you need new shocks. When i apply the brakes to a hard stop at 10 mph the truck bounces several times. I feel it is unsafe. My truck has 4000 miles on it, if it had 60000 I'd be replacing the shocks with heavy duty shocks. I have an appointment next week with a local dealer but have little faith that anything will come of it.

Yep, that's how I described it to my wife and the guy at the dealership, feels like the shocks are bad, as it feels like an old '84 Buick Regal bouncing down the road at times.

Wheelguy · August 1, 2019

On 7/30/2019 at 11:05 PM, econometrics said:

Mostly, this is just the result of trucks getting lighter, but able to carry more payload. Stiff rear ends when empty.

I agree 100%.

I wonder how bad the carbon fiber beds are going to be with this? My 2019 Denali isn't the greatest (22" wheels/ stock 50 aspect ratio tires) and the loaner I'm currently driving (2019 2.7L SLE 4X4 without Multipro tailgate, smaller wheels & larger aspect ratio tires) is just about as bad. Can't believe how much lighter the normal tailgate is compared to the Multipro.

Edited August 1, 2019 by Wheelguy

ILSilverado · August 1, 2019

Mine is excessively bouncy I was going to change out the shocks. I have a 2019 regular Silverado with 4 WD.

Inside Man · April 30, 2020

Bumping the thread, as I just bought a 2020 Trail Boss and I get the same sway but less now that I installed 295/70/18 and new wheels. My son just bought a RWD 2020 Silverado RST and it also sways? Anyone find out what's the issue?

Edited April 30, 2020 by Inside Man
added photo

Giantpeaches · April 30, 2020

Shitty rancho shocks

Gangly · May 1, 2020

Its a truck guys, they are designed to work meaning they are engineered to perform tasks associated with hauling loads in the bed, trailer, etc. By default, they will perform best with a little weight in the back. Its very hard to design an unloaded truck to handle like a car over rough roads, but then be stiff enough to support a bed loaded with a couple thousand lbs of weight. Add in the fact that most trucks come with wheels ranging from 17 inches up to 22 inches, and there is no way to design a shock or spring system to accommodate the variables in suspension stresses based on the multitude of available sidewall dimensions (flex). There's gotta be some understanding of what your purchasing and the intent of design for what your purchasing. A truck riding on an 18 inch wheel is going to sway and roll significantly more than a truck riding on a equivalent diameter tire but utilizing a 20" wheel. If you don't grasp the concept of what a truck is ultimately designed for, or don't like the "quirks" associated with making a vehicle capable of its intended purpose, then you might be better served by purchasing a Tahoe or Yukon and you will be much happier.

Edited May 1, 2020 by Gangly
Edit

Pinnacle · May 4, 2020

Yup, Ive test drivin 6 and every single one of these trucks regardless if its GMC or Chevy feels "loose" at highway speeds to the point where it makes you feel uncomfortable, its got nothing to do with shocks but the design of the truck.

Thomcat · May 4, 2020

I have an RST with optional 22" wheels and Bridgestone Alenzas with stock shocks and springs. Rear axle would hop on bumps, especially hard acceleration from a stop into a turn and had a vibration at 55-60. Had to be the lighter bed because 100 lbs over each wheel in the bed calmed it right down.

Once the standard shocks wore in and tires were seated at about 1000 miles took it for a road force balance at the dealer. It cured almost all of the problem the balance without the added weights disappearing by 4K miles. Now at the point where the ride is at least as good if not better than my '16 Z71 18's with more aggressive Wranglers, and stability and handling of the T1 with the 22's even at 70 mph is much much better than was my K2..

ILSilverado · May 4, 2020

On 7/30/2019 at 11:54 PM, Wiggums said:

Exactly the same situation I was in. That is a liability issue, I was more angry over the fact I could have killed the guy walking on the side of the road. GM fanboys got all over me on this, questioning my experience, etc. "My Ford did the same" I've driven 4x4's and none were this bad. I was going about 70 km/h, maybe 80 km/h when it happened. That is why my next car isn't going to be a Chevrolet unless they address this.

Having owned both a 2019 new version and now a 2020 I can confirm they fixed this issue on the 20s

Wiggums · May 4, 2020

2 hours ago, ILSilverado said:

Having owned both a 2019 new version and now a 2020 I can confirm they fixed this issue on the 20s

Were both RST 4x4s with twin tube shocks?

ILSilverado · May 5, 2020

21 hours ago, Wiggums said:

Were both RST 4x4s with twin tube shocks?

I think its more spring related .

Wiggums · May 5, 2020

2 hours ago, ILSilverado said:

I think its more spring related .

RST owners were the only ones who had that issue, not the others. That was why I asked.

Mine was so bad it went sideways and I wasn't accelerating or braking. The back end had no traction and was wildly flailing back and forth.

My first incident was on a regular road that was caked in mud and I nearly hit a guy on the sidewalk. That was about a year ago when we had the floods and mud came from the nearby hills.

I'd have to point out that kind of ripple was not common, it has to be at the right rhythm for that to happen.

I drive on the dirt road to the ranch every day and I have run into that issue quite a few times. The Cheyenne RST is not a truck I'd want to be driving on the dirt road even at 30 mph (if it is straight, smooth, with excellent visibility). I have driven all the other 4x4's much faster than that and all handled better. I don't even drive it anymore, it has been sitting there for the past six months.