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Help with torsionbars

doidera00
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doidera00 Enthusiast

doidera00

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Hi i have a 2021 sierra 3500 4x4 diesel with the snow prep package. My truck rides really stiff and im used to drive hd truck even though ive never owned one before. My friends f350 rides so much softer than mine. Anyways i wanted to soften the from suspension a little. Its hard to find info on torsion bars. From my understanding the snowprep package comes with heavier torsion bars. The part number on it for left side is 84745489. When i put that on gmc parts it says its for a 2wd truck. Weird. Wanted to know if anyone knows if the torsion bars for the 3500 and the 2500 was the same. Cognito make a softer rate torsion bar but its for all trucks 2500 and 3500 gas and diesel. Im afraid if i change to that it might be too soft. Now if the 3500 and the 2500 has different rates maybe i could go down to a 2500 spring rate. 
 

any help is appreciated. 

Another JR Senior Enthusiast

Another JR

Posted
Posted (edited)

There are multiple part numbers and stiffnesses of torsion bars depending on the specific cab and bed, diesel vs gas, camper pkg, and snow plow package. There’s a table on line showing all the configurations. I’ll see if i can find it again. You should be able to contact an oem parts dealer and figure out the base torsion bars for your cab/bed/engine. On some of the configurations the camper pkg is one step up and the plow is another step up in stiffness and axle rating. Other configurations just go up the same one step for both options. If you feel your truck rides like a Ford, and if your truck is willing to forgive you for saying that, I recommend you back down to the base torsion spring even if it’s two steps. I have the camper package and, while it’s still a comfortable ride, it’s stiffer than I wanted for our lightweight slide in camper. I’m thinking of installing the base torsion springs. 

Edited by Another JR
MTU Alum Enthusiast

MTU Alum

Posted
Posted

In general, 2500 and 3500 srw torsion bars are the same for the same wheelbase and engine.  The diesel snow plow package only goes up one size whereas the gas plow prep goes anywhere from one to three sizes.  

 

#iworkforGM 

03 Cobra Enthusiast

03 Cobra

Posted
Posted
On 8/16/2021 at 1:58 PM, Another JR said:

There are multiple part numbers and stiffnesses of torsion bars depending on the specific cab and bed, diesel vs gas, camper pkg, and snow plow package. There’s a table on line showing all the configurations. I’ll see if i can find it again. You should be able to contact an oem parts dealer and figure out the base torsion bars for your cab/bed/engine. On some of the configurations the camper pkg is one step up and the plow is another step up in stiffness and axle rating. Other configurations just go up the same one step for both options. If you feel your truck rides like a Ford, and if your truck is willing to forgive you for saying that, I recommend you back down to the base torsion spring even if it’s two steps. I have the camper package and, while it’s still a comfortable ride, it’s stiffer than I wanted for our lightweight slide in camper. I’m thinking of installing the base torsion springs. 

 

Hey JR, if you can find that table with the torsion bars I would really appreciate it!  That's because I am getting impatient waiting for my order to get picked up and keep looking online for something close to what I'm trying to order.  There are many trucks that are close but many of them have the snow plow/camper package and I would love to see how far those torsion bars are from the regular bars on a '22 3500HD crew cab SRW gasser.  Thanks!

doidera00 Enthusiast

doidera00

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Posted
On 8/16/2021 at 1:58 PM, Another JR said:

There are multiple part numbers and stiffnesses of torsion bars depending on the specific cab and bed, diesel vs gas, camper pkg, and snow plow package. There’s a table on line showing all the configurations. I’ll see if i can find it again. You should be able to contact an oem parts dealer and figure out the base torsion bars for your cab/bed/engine. On some of the configurations the camper pkg is one step up and the plow is another step up in stiffness and axle rating. Other configurations just go up the same one step for both options. If you feel your truck rides like a Ford, and if your truck is willing to forgive you for saying that, I recommend you back down to the base torsion spring even if it’s two steps. I have the camper package and, while it’s still a comfortable ride, it’s stiffer than I wanted for our lightweight slide in camper. I’m thinking of installing the base torsion springs. 

if you can find the table that would be awesome.  i looked the part number for my torsion bar and it says its for a 2wd gas.  my truck is 4wd diesel. i could not find any info on what the stiffness of the oem torsion bars are.  it would be nice to know how i can step down. people at the dealer are so dumb. you try to explain what you want, and first they dont know the answer and second they say you cannot change the torsion bar to something different from what the truck came with.

 

Another JR Senior Enthusiast

Another JR

Posted
Posted

I spent some time trying find it again via web search last night.   No luck. I know I posted a link to it in a previous string, so I’ll look at my posting history next. 
 

I don’t remember the table showing part numbers - just axle ratings with the various configurations and options, which told you how many 400 lb steps you were above the base suspension for your configuration for the camper and plow options.  

MTU Alum Enthusiast

MTU Alum

Posted
Posted

4400 FGAWR 84745473/5

4800 FGAWR 84745477/9

5200 FGAWR 84745481/3

5600 FGAWR 84745485/7

6000 FGAWR 84745489/91

 

In general, diesel crew cab sb 4wd are 5600 FGAWR and gas crew cab sb 4wd are 4800 FGAWR without heavy front or snow plow options.

 

If you have any other models, I can look up when I have time.  

 

#iworkforGM 

  • Thanks 1
03 Cobra Enthusiast

03 Cobra

Posted
Posted
1 hour ago, Another JR said:

I spent some time trying find it again via web search last night.   No luck. I know I posted a link to it in a previous string, so I’ll look at my posting history next. 
 

I don’t remember the table showing part numbers - just axle ratings with the various configurations and options, which told you how many 400 lb steps you were above the base suspension for your configuration for the camper and plow options.  

 

JR, thanks for investing the time to look for it.  Too bad GM doesn't make it easier to find.  Build and price for the '22 2500s gives the option for a "heavy duty front spring/camper package" and for the 3500s you can choose the same package or you can choose a "snow plow prep/camper package" and that one does list "heavy duty front springs" as included but none of the three give you any indication how heavy duty they are or especially how much over stock they are rated.  I thought I could find a clue in the 149 page 2022 GMC standard equipment and options document (pdf saved on my computer) but it was vague as well.  

03 Cobra Enthusiast

03 Cobra

Posted
Posted (edited)
On 8/16/2021 at 10:35 AM, doidera00 said:

Hi i have a 2021 sierra 3500 4x4 diesel with the snow prep package. My truck rides really stiff and im used to drive hd truck even though ive never owned one before. My friends f350 rides so much softer than mine. Anyways i wanted to soften the from suspension a little. Its hard to find info on torsion bars. From my understanding the snowprep package comes with heavier torsion bars. The part number on it for left side is 84745489. When i put that on gmc parts it says its for a 2wd truck. Weird. Wanted to know if anyone knows if the torsion bars for the 3500 and the 2500 was the same. Cognito make a softer rate torsion bar but its for all trucks 2500 and 3500 gas and diesel. Im afraid if i change to that it might be too soft. Now if the 3500 and the 2500 has different rates maybe i could go down to a 2500 spring rate. 
 

any help is appreciated. 

 

Looking at what MTU just posted and comparing to your part number you have the baddest bad boy of the bunch!  6k lbs!  Guess when they combine the heavy diesel and the snow plow prep you deserve the best!  All kidding aside, and not trying to insult your intelligence at all, have you checked the air pressure in your front tires?  Maybe it's crazy high from the dealership.  Even if its not too high try turning it down to 45 or 50 or something like that.  It will make a noticeable difference.  I have a '15 2500HD with the snow plow prep and the ride is entirely different at 60 vs 50 psi in front.  I might take a little hit to the mpg but I don't care.  I adjust mine back up when towing my camper but for daily driving I adjust the front and rears down and it turns it into a different truck.  Give it a shot if you haven't yet.

Edited by 03 Cobra
MTU Alum Enthusiast

MTU Alum

Posted
Posted (edited)
1 hour ago, 03 Cobra said:

 

The F60 - heavy front suspension / camper raises your FGAWR by 400 lbs (next size up).

 

VYU - snow plow prep / camper raises your FGAWR to 5600 lbs on gas engines and 6000 lbs on diesel.

 

On a lot of 4wd diesel models, F60 and VYU get you the same suspension.  

 

#iworkforGM 

Edited by MTU Alum
Forum software sucks
03 Cobra Enthusiast

03 Cobra

Posted
Posted
50 minutes ago, MTU Alum said:

The F60 - heavy front suspension / camper raises your FGAWR by 400 lbs (next size up).

 

VYU - snow plow prep / camper raises your FGAWR to 5600 lbs on gas engines and 6000 lbs on diesel.

 

On a lot of 4wd diesel models, F60 and VYU get you the same suspension.  

 

#iworkforGM 

 

MTU, since you are our guy on the inside can you please sanity check this table I made?  It might help us bring everything together.

 

image.thumb.png.de919e8dfa7221f2b6c1b9260819039f.png

 

 

 

MTU Alum Enthusiast

MTU Alum

Posted
Posted
2 hours ago, 03 Cobra said:

 

MTU, since you are our guy on the inside can you please sanity check this table I made?  It might help us bring everything together.

 

image.thumb.png.de919e8dfa7221f2b6c1b9260819039f.png

 

All gas are 5600 lbs with snow plow.

 

 

03 Cobra Enthusiast

03 Cobra

Posted
Posted
6 minutes ago, MTU Alum said:

 

 

Copy that.  Here is the updated snow plow table with a standard springs table if you want to take a glance at that one too.

 

image.thumb.png.676902a2b50e34458c254f0b3131c5ef.png

Dunn Senior Enthusiast

Dunn

Posted
Posted

MTU works for GM so his info should be solid

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