Jump to content

2020 vs 2021 suspension tuning

Dirtdevilnc
 Share

Recommended Posts

Dirtdevilnc Enthusiast

Dirtdevilnc

Posted
Posted

Hi all, I am new to the GM ownership world.

I recently purchased a 2020 crew cab LTZ with 6.2 and Z71 package. One of the most notable things to me is that its all over the place when you hit road irregularities and upon hitting any large potholes etc. it feels like the whole thing is a giant jello blob. Its so bad that the entire structure squeaks and rattles. The crashing and bouncing is somewhat reminiscent of my 2006 F250.

My truck is currently at the dealer and they gave me a 2021 double cab Z71 RST. Its like night and day difference in the solidity and seems to just skip across road irregularities as opposed to bound over them and get upset by them. One of the differences between the two is that the loaner truck has Goodyear Wrangler A/Ts versus the BridgeStone Dueler A/Ts on my truck.

I have heard that from 2019 to 2020 GM retuned the suspensions of the Silverados and Sierras. I did a bit of research online and it does appear that for example the rear leaf springs have different part numbers between 2019 and 2020 for similarly equipped trucks. 

Is anyone aware of any suspension changes between 2020 and 2021, how much can be attributed to the difference in tires? 

thx!

redwngr Senior Enthusiast

redwngr

Posted
Posted

Tire pressures between the 2 trucks? 

 

Rim diameters of wheels installed?

(factory tire OD's are very similar, so larger rim diameters have shorter sidewall tires)

 

  • Like 1
TNTSierra Senior Enthusiast

TNTSierra

Posted
Posted

Rim size does make a bit of difference on the ride of vehicles, but these new car manufacturers are using sizes from 17 to 22 so they test the vehicles on each of these rim sizes. 
It’s not like 20 years ago when all they had were 17 inch rims/tires and the aftermarket world of 20” rims looked HUGE! , yet they rode “harsh” on the roads, because they didn’t come from the manufacturers ever being tested with those size rims. They now test all these trucks on all different road conditions with different size rims/tires a lot more than they ever used too. 

I do believe after driving a 2021 RST Z71 for the past week while my truck was getting fixed and putting over 1200 miles on that truck, that GM did “tinker” with the suspension a bit because that truck rode more “firm” than my 2019 HC. My HC likes to “float” and is a little bouncy on uneven roads. This 2021 RST Z71 rode differently. It rode like some of the comments going on about the Bilstein 5100s. More firm, less bouncy, and planted. 
My step dads Sierra also rides better, more planted than my HC as well and is noticeably quieter. By no means is my truck loud, I LOVE IT. Was glad to get it back, but it is noticeable. 

If you go back to ALL the reviews on 2019 trucks by any car magazine reviews: there were always 2 negatives: crappy interior and poor/bouncy ride over uneven surfaces. 
GM is taking care of the interior next year (btw, I like the current interior)

And I think they have made these newer trucks more planted. 

MaverickZ71 Senior Enthusiast

MaverickZ71

Posted
Posted (edited)

I read somewhere where GM planned to revise their suspensions after the car magazines complained about the '19s.  I'll see if I can find where I saw that.

 

But I'm also starting to believe that Bridgestone tires are just "stiff" compared to some other tire brands. 

 

I got 74K miles out of the OEM Bridgestone Dueler A/T RH-S tires that were rated at 40K miles.  Never had a 4x4 truck tire last that long without a belt separation or other problem. 

 

Appreciated the longevity, and OWL tires of the original type were no longer available, so I replaced them with OWL Bridgestone Dueler H/L Alenza Plus tires, hoping the new 'highway' tires would be a little quieter, get better fuel mileage, and ride a little softer than the old 'all-terrain' tires they replaced.  Not so much. 

 

In my opinion, the Alenza's ride rougher than the RH-S's did, until you get about 20+ miles of highway trip heat into them.  And the RH-S weren't the softest/smoothest tires I'd ever had.  My GM dealer said they were aware of complaints on the new full-sized SUVs with Bridgestones.  The Firestone/Bridgestone dealer said they are known for tough belts and stiff sidewalls--that's how they get their higher-mileage warranty.  And they drive them on the freeway for 5+ miles to get some heat into them before they'll attempt a rebalance.  Never heard of that before.  Next time, I think I'll go with Michelins.

Edited by MaverickZ71
OnTheReel Senior Enthusiast

OnTheReel

Posted
Posted

Suspension was retuned for the 2020 model year. There’s a thread someplace here that showed different part numbers on the rear springs from 2019 to 2020, even with the same suspension packages on each example. I haven’t heard anything about the 2021 suspension being changed again.

  • Like 1
Rodek Enthusiast

Rodek

Posted
Posted

I've noticed that my 2020 High Country's ride quality has improved after putting about 5,000 miles on it. If your new truck doesn't suffer a manufacturing error you may get a better ride after things break in. 

Troger Enthusiast

Troger

Posted
Posted

I just traded a 2019 to a 2021 Denali and the ride is night and day difference to me.  The 2021 seems to be smoother and not as bouncy and feels more solid on the road.  I also went from 20" to 22" wheels so not sure how much that played into the ride difference.

winks79 Enthusiast

winks79

Posted
Posted

Agree, they did make changes after 2019 to them, but the main problem is not the tires, it is the crappy Rancho shocks if you have the off road package. I installed the Bilstein 5100's all the way around on my 2019 Sierra, and it is like driving a different truck. Could not believe the difference. Firmer ride, in a good way, and handles all roads so much better. No more bouncing all over the place over speed bumps or uneven pavement. This thing stays planted now. Money well spent for me. Should have come with these from factory IMO. Bilstein's were standard equipment on the 90's GM Z71's.

Mike Borowski Enthusiast

Mike Borowski

Posted
Posted

I felt the same about my 2020, I put Bilsteins on the rear around 500 miles, a few thousand miles in once the leafs broke in it's night and day.  I love the way it drives now.  Worthy $180 investment no doubt!

luke1333 Enthusiast

luke1333

Posted
Posted
On 1/5/2021 at 8:52 AM, Mike Borowski said:

I felt the same about my 2020, I put Bilsteins on the rear around 500 miles, a few thousand miles in once the leafs broke in it's night and day.  I love the way it drives now.  Worthy $180 investment no doubt!

Same here, Bilsteins on the rear make a world of difference! Tempted to do the fronts too!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      So, do I go elbow-deep on this thing or list it for sale and play dumb? Seems to "runs good."   I'm about $1200 away from having: -a rebuilt injector ($300) -a new cat ($250) -a new cat back exhaust (OE style) ($300) -a new AC compressor ($200) -AC refrigerant charge ($150)   In theory, this should rectify the obvious detracting issues from its value and operability. Cold AC with a non-squeaking AC pulley both sounds and feels good. An exhaust that isn't cut/hacked in 17 different places and doesn't vibrate on a crossmember would make it sound and feel less janky. A working cat would help the stink, and will save the earth, but *if and only if* the fuel system is working properly, which would also address the intermittent "rich" CEL.   Heard a good one... CEL for "Rich condition" means you haven't spent enough money on the truck lately, and it's letting you know.   Rebuilding the injector would seem to be the most important part. Replacing the cat would be secondary. I don't think mine is plugged or overly restricted, but it might be a little restricted? I have no good way to tell other than seat of the pants feel. I hate the smell.   The current theory is I have a rich idle problem: A bad fuel pressure regulator, or a leaking injector(s) being the highest probabilities. I already replaced the FPR but that doesn't mean its replacement isn't also bad. It was a new part from Dorman, but the packaging looked like it had been sitting on a shelf for 20 years.   This is the (single) upstream O2 sensor shown at idle. I'm getting a lot of "rich" it seems. Sometimes it stays high like that and doesn't drop down. That makes me think it's processing injector leaks or a partially stuck open injector.     Other times it looks like this. Nice oscillations between rich and lean, which is what I think it should be. Under load and at speed, the oscillations are nice and tight and uniform looking, high and low.     Fuel trims suggest the PCM is compensating pretty hard at idle to pull fuel out. But it's not enough to trip a CEL. Something about slowing to a stop: brake vaccum booster, EGR, or the EVAP purge is delayed, or there's pooled fuel in the intake again that's draining into a cylinder is enough to set the CEL. Of course, in two days of driving, it hasn't set. I was hoping to actually look at the freeze-frame data when it sets. IAT is high because it's idling on an 83 degree day here.  
    • Another JR
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By Another JR · Posted

      Have considered installing a DC to DC charger in your camper to replace your isolator?  
    • newdude
      Gas fill door

      By newdude · Posted

      Common failure.  You need to replace the fuel door housing.   The painted cover transfers over to the new housing.  To remove the old one there is 4 spots where you poke the plastic to release it.  
    • newdude
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By newdude · Posted

      No such thing as regenerative braking on a pure ICE vehicle.     Regenerative braking is the re-capture of energy from electric motors and stores it in the battery pack.  So hybrids, PHEV and EVs have regenerative braking.     What you are seeing is the charging system changing modes is all.  Its likely entering charge mode for some sort of reason is all.  All of the charging modes will be listed below.   As for L10 vs D.  L10 turns off automatic grade braking.  L10 puts you in control of grade downshifts where in D it will automatically do it based on brake pedal position and other factors.  Otherwise L10 and D drive exactly the same aside from that one aspect.    Battery Sulfation Mode The BCM will enter this mode when the interpreted Generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2–3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.   Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met:   Windshield wipers are ON for more than 3 s. Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control module via serial data. High speed cooling fan, rear defogger, and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. The estimated battery temperature is less than 0°C (32°F). Battery State of Charge is less than 80%. Vehicle speed is greater than 145 km/h (90 mph) A current sensor malfunction exists. System voltage is determined to be below 12.56 V When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9–15.5 V, depending on the battery state of charge and estimated battery temperature.   Fuel Economy Mode The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 A and greater than −8 A, and the battery state-of-charge is greater than or equal to 80%. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5–13.1 V. When fuel economy mode is active, the generator is not charging, only maintaining open circuit battery voltage. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.   Headlamp Mode The BCM will enter Headlamp Mode when ever the head lamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.   Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 s.   Tow/Haul Mode (if applicable) Pressing the Tow/Haul Mode button located on the center stack, the vehicle system voltage is raised and the remote (non-vehicle) battery will be charged. Having the headlamps on will raise the system voltage and if the Tow/Haul button is applied it will not serve any purpose. The voltage is regulated between 13.9-14.5 V.      
    • jaszr2
      Active Grille Delete

      By jaszr2 · Posted

      Hello from Australia Just sharing that there is now a way to delete the active shutters entirely with just a plug in module. Opens up tons of room to light bars etc.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...