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2021 AT4 HD Snow/Camper package reversion?

Sheen
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Sheen Enthusiast

Sheen

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From what I've determined the Snow/Camper upgrade to the 2021 AT4 Sierra 2500  [with regard to suspension]  includes a heavier duty torsion bar.  

 

I purchased an AT4 with this package, even though I didn't need or desire the package, because it had everything else I wanted.

 

Would it be possible, and how involved would it be, to revert the torsion bars to the stock versions (like an AT4 without the snow/camper package)? 

 

Now I will catch a lot of heat from you guys I know, for bringing up ride quality in an HD truck.  However I have a feeling this would make a notable improvement. Why have stiffer than necessary?  I will be towing with it in the near future, but will do a lot of daily driving too.  

 

In addition, I keep reading the rancho shocks are no bueno.  Thoughts?  

 

Thank you gents!

Edited by Sheen
Another JR Senior Enthusiast

Another JR

Posted
Posted

The torsion bars can be swapped out. There have been other recent threads where how to do it was covered. It’s a somewhat heavy diy job because of how big the bars are and how tight they may fit in the front lower control arm.  If you are not a diy person the dealer or another mechanic can do it. Three hours labor plus parts would be my guess from watching the videos. Torsion bars will be in the ballpark of $250 each. So maybe around $1000 to $1200 have them swapped out.  Just guesstimating. 

Another JR Senior Enthusiast

Another JR

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Another thing to consider is whether you want to try to restore the active louver system in front of the radiator that is on trucks without the snow plow package. 

Sheen Enthusiast

Sheen

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I could definitely handle the job myself IF the bars can be negotiated out by just removing the torsion bar keys.  If I'd have to remove the control arm etc, then no, I don't want to get into that.  

 

What!?!?  I'm missing the louver system too?  Yep, you're right, not there.  Even if you could have that installed, would the software be present to run it!?    How much better on average do these things improve mpg you think?

 

Thanks so much for your help.

Another JR Senior Enthusiast

Another JR

Posted
Posted

You don’t need to pull the control arm, but you do need to remove a frame cross member further back just to get the bar out of the frame once it’s free. Search for videos on youtube. Someone else commented that the torsion bar front end fits tightly in the lower control arm, and may take serious hammering to break it loose. I have no experience with it myself. 

newdude Senior Enthusiast

newdude

Posted
Posted (edited)

I don't think the ride difference will be different enough to even notice.  I sure have never noticed a difference in a plow prep vs. non plow prep HD (driven dozens of them at work).  

 

At the end of the day its still an HD.  Stiffer frame, stiffer axles, stiffer tires, massive leaf springs.  

 

Edited by newdude
Sheen Enthusiast

Sheen

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Ok thanks guys. I ordered up the non-stow prep bars.  I'm gonna throw them in and see. I see what you're saying about the crossmember.  Should be able to get that out fairly easy.   Luckily it's new and not all rusted up yet, so I'm hoping be a little easier to pound that bar out of the control arm.

 

Ps. You might be right newdude.  I'll report back.  Might be a couple weeks tho.

Logan Lanfear Enthusiast

Logan Lanfear

Posted
Posted

Something that might be worth mentioning too is the future resale of the truck. I'm guessing that you'll get a better ride if you run your tires at 40psi instead of 80. 

But if you ever do go to sell the truck down the line the right thing to do would be to mention that is has the regular truck springs not the snow/camper ones. It might be worth keeping your stock ones. (I like keeping all of my stock parts if I chose to modify)

Im interested in the results as most of the 2500 trucks where I live come with the plow prep. 

Sheen Enthusiast

Sheen

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3 hours ago, Logan Lanfear said:

Something that might be worth mentioning too is the future resale of the truck. I'm guessing that you'll get a better ride if you run your tires at 40psi instead of 80. 

But if you ever do go to sell the truck down the line the right thing to do would be to mention that is has the regular truck springs not the snow/camper ones. It might be worth keeping your stock ones. (I like keeping all of my stock parts if I chose to modify)

Im interested in the results as most of the 2500 trucks where I live come with the plow prep. 

That is excellent advice.  Rest assured I always fully disclose whenever I sell anything.  I believe very strongly into treating others the way I would like to be treated, but I appreciate the reminder none-the-less.  And great idea! I'll keep those bubble wrapped in the basement, and they'll stay brand new.  And who knows, maybe one day I'll get a camper;)  Also, for sure I'll report back - promise.  Thanks Logan!

Sheen Enthusiast

Sheen

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Oh and Logan, about the PSI.  My door sticker calls for 60 Front, 70 Back.  I've taken the front down to 54 and the back 52. Cold. The ride does seem a lot better.  Could I actually go lower than that without a problem?  Sidewall max is 80.

It's Tim Senior Enthusiast

It's Tim

Posted
Posted
On 5/10/2021 at 5:39 PM, newdude said:

At the end of the day its still an HD.  Stiffer frame, stiffer axles, stiffer tires, massive leaf springs.  

 

True, the unsprung spring rates whether plow package equipped or not are probably identical.

Logan Lanfear Enthusiast

Logan Lanfear

Posted
Posted
On 5/10/2021 at 10:19 PM, Sheen said:

Oh and Logan, about the PSI.  My door sticker calls for 60 Front, 70 Back.  I've taken the front down to 54 and the back 52. Cold. The ride does seem a lot better.  Could I actually go lower than that without a problem?  Sidewall max is 80.

I run 40 in my E range tires. I am not sure what rating your tires have but I would assume its E or more. Google your specific tire and you might find a minimum rating but sidewall flex is probably the biggest thing. With 40 I dont have any 'squish' in the rear tires and just a tiny bit in the front. 

It was a huge improvement on the ride to go from the 60 I was running down to 40. Felt like a different truck. 
Just remember to air back up when you're towing or loaded heavy. 

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Sheen Enthusiast

Sheen

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Posted (edited)

So I actually ended up getting a set of 2020 Silverado 2500 torsion bars on ebay. These are the stock bars that would have been in my AT4 had I not bought one with the snowplow package. Measuring the diameters and calculating volume they had 7 or 8% less volume than the snowplow bars. I installed them, (super easy) and the ride is notably better. However, what I'm learning is that the relationship between the jouncers and the control arms are VERY important. Interestingly also, there are 4 jouncers on the front end of the truck. I'll call them extreme forward and middle forward, not to be confused with the rear jouncers above the leaf springs. The extreme forward and middle forward jouncers do not meet the control arm at the same time. In other words as you lower the rake of the truck the middle forwards will touch the control arm before the extreme forwards. I"m guess there is maybe 1/8 to 3/16 of an inch difference in when they touch the control arm. I have found through experimentation that squishing the middle forward jouncer just a little to allow the extreme forward jouncer to just kiss the control arm results in my best ride so far. If I raise it up from there where the middle forward jouncer kisses, and the extreme forward jouncer is about 1/8 inch above control arm, this has a noticeably worse ride. Obviously the higher the rake from there the worse the ride gets. ( I do drive the truck aggressively over bumps after every adjustment before I even check measurements or jouncer positions)

As far as tire pressure: I reached out to Goodyear and received the documents to account for different psi allowable under different loads.( thank you Logan)  I'm assuming my truck carries 60% of its weight on the front wheels and 40% on the back.  Assumption is based on multiple weight reports that show a 57/43 % split, albeit on older duramax trucks. And just for daily driving (not towing or hauling) a very comfortable figure of 9500 gross weight (full gas tank, myself, wife, and two kids, and 400 lbs of whatever else I put in the truck) allows me to go down to 55psi in the front and 40psi in the back. I've got 56 in the front and 46 in the back right now. Interestingly I had 56 in front and 50 in back and the ride seemed better than when I dropped the rears to 46. I'll continue experimenting there, but at least I know I'm 100% safe running those lower pressures now that I have the tire docs.  Just can't forget to inflate before I haul.  And I won't.

If anyone has any thoughts or concerns for me that don't include "why would you buy a HD truck and then ****** about the ride" I'd love to hear them. By the way, I've improved the ride already without compromising the handling or towing capacity or payload. From what I can tell so far using the stock non-snowplow torsion bars reduced my forward axel allowable weight from 6600 to 6000 but this has zero implication for towing or hauling at the levels I will be using it for.

If I still cannot get satisfied my next step will be upgrading the Rancho shocks, moving to an 18 inch wheel vs the 20 I have.  Because I test drove a SLT 2500 non-snowplow with 18 inch wheels and it felt so much better than my AT4.  But it didn't look as cool Lol.

Edited by Sheen
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