Jump to content

Help with torsionbars

doidera00
 Share

Recommended Posts

03 Cobra Enthusiast

03 Cobra

Posted
Posted (edited)
1 hour ago, MTU Alum said:

2500 diesel crew cab runs 5600 FGAWR. 

 

Got it.  Once MTU has blessed the data as correct I would be happy to provide the simple Excel file to anyone that wants it.  In Excel it can be updated to include any other formatting and/or information you want.  Just PM me your email address.

 

image.thumb.png.e9a4dc1f8468209aef79a93584de7a2b.png

Edited by 03 Cobra
It's Tim Senior Enthusiast

It's Tim

Posted
Posted
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. 

Might not want to change anything until you determine the static spring rate.

doidera00 Enthusiast

doidera00

Posted
  • Author
Posted
19 hours ago, MTU Alum said:

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 

mine is the 6000. i looked at teh sticker that is on the torsion bar. mine came factory with teh snow plow prep

doidera00 Enthusiast

doidera00

Posted
  • Author
Posted
19 hours ago, 03 Cobra said:

 

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.

i have the pressure set to 50F 70R.  i dont want to go any lower because it might set of the TPS light

doidera00 Enthusiast

doidera00

Posted
  • Author
Posted
15 hours ago, MTU Alum said:

 

if i was to go down to a 5200, do you know if that would be a bad thing.  i dont really tow that much.  sometimes i tow my camper that weighs around 11000 lbs

03 Cobra Enthusiast

03 Cobra

Posted
Posted
4 minutes ago, doidera00 said:

if i was to go down to a 5200, do you know if that would be a bad thing.  i dont really tow that much.  sometimes i tow my camper that weighs around 11000 lbs

 

Just as an FYI when unloaded I run with the rears at 60 and the fronts at 50 or 55 and never see a light.  Also I have the 5200 lbs front springs (snow plow prep) and do tow a travel trailer 8k - 10k lbs with a weight distribution hitch (puts weight on the front end of the truck) and it tows just fine.  Personally I wouldn't switch to lower springs even if someone gave them to me just because it wouldn't be worth the effort meaning the 5200s are fine.  As long as they fit I don't see why it would be a problem.

doidera00 Enthusiast

doidera00

Posted
  • Author
Posted
10 minutes ago, 03 Cobra said:

 

Just as an FYI when unloaded I run with the rears at 60 and the fronts at 50 or 55 and never see a light.  Also I have the 5200 lbs front springs (snow plow prep) and do tow a travel trailer 8k - 10k lbs with a weight distribution hitch (puts weight on the front end of the truck) and it tows just fine.  Personally I wouldn't switch to lower springs even if someone gave them to me just because it wouldn't be worth the effort meaning the 5200s are fine.  As long as they fit I don't see why it would be a problem.

i wanted to change from the 6000 to either the 5600 or the 5200 because my front end is just too stiff.  i know i bought a sierra 3500 but i never really carry weight on it.  i just bought it because i like the truck and maybe one day i wanted to delete and tune and in my state you dont need emissions on a 3500 but you do on a 2500

MTU Alum Enthusiast

MTU Alum

Posted
Posted
On 8/19/2021 at 8:14 AM, 03 Cobra said:

 

Got it.  Once MTU has blessed the data as correct I would be happy to provide the simple Excel file to anyone that wants it.  In Excel it can be updated to include any other formatting and/or information you want.  Just PM me your email address.

 

image.thumb.png.e9a4dc1f8468209aef79a93584de7a2b.png

This looks correct from 2020 to the mid cycle.

 

#iworkforGM 

MTU Alum Enthusiast

MTU Alum

Posted
Posted
On 8/19/2021 at 12:15 PM, doidera00 said:

if i was to go down to a 5200, do you know if that would be a bad thing.  i dont really tow that much.  sometimes i tow my camper that weighs around 11000 lbs

The problem with going down to 5200 is it may not trim properly.  You may not have enough adjustability in torsion bar adjuster based on your front axle weight.  

 

#iworkforGM 

  • 2 weeks later...
Stand By Enthusiast

Stand By

Posted
Posted

How long have you been driving the truck? I don't think the truck comes into its own until at least 5000 miles. MPG/Shifting/Handling, etc.  There's no way my father in laws 2019 long bed cc f350 diesel rides better than my 20 gas cc 2500 with plow prep. My tires are between 55 and 60 depending on temp. Bad Michigan roads will raise your awareness level of what your driving (well, except maybe not Subaru drivers). Expansion joints are bearable in this truck. Same with pot holes and patches, though 20" wheels also help with the potholes compared to 17". Been down the same washboard dirt roads in mine as in the Ford above, and my older cc 1500 and this one is the most bearable. This 20 with the tighter front ends also holds linea better in a curve than my 1500. My only issue is a reduced turning radius than my older truck, for parking my 25' boat in the back yard. But just a couple more back ups and it's done. Made up the time with the back up camera to hook it up, though. Diesel plow prep is only 400lbs more, but that's probably negated by the additional engine and transmission weights.

  • 4 years later...
Petrolhead Enthusiast

Petrolhead

Posted
Posted
On 8/22/2021 at 6:28 AM, MTU Alum said:

The problem with going down to 5200 is it may not trim properly.  You may not have enough adjustability in torsion bar adjuster based on your front axle weight.  

 

#iworkforGM 

Hi all,

I realize that this is an old thread, but I could use some help on the Torsion bar parts list for the earlier years, say 2015-2019 

Thanks

Another JR Senior Enthusiast

Another JR

Posted
Posted
11 hours ago, Petrolhead said:

Hi all,

I realize that this is an old thread, but I could use some help on the Torsion bar parts list for the earlier years, say 2015-2019 

Thanks

There’s a different subforum for those trucks. You might get a faster response there. 

Petrolhead Enthusiast

Petrolhead

Posted
Posted
6 hours ago, Another JR said:

There’s a different subforum for those trucks. You might get a faster response there. 

Thanks. I appreciate it

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

    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      Can it still be Assembled I?    Stribeck says that we need a certain amount of viscosity under conditions of load and velocity to prevent two surfaces of a know roughness from tearing each other asunder. And we have marketing trying to tell the masses that those two surfaced require less of that commodity due to more exact limits being placed on the same old clearances. We also know that there are limits to how hard something can before it becomes to brittle to be viable and to smooth to 'wet' the surface and that both of those conditions have been known and met since about the Second World War.    That viscosity value shook out at 10 centistokes at 212 F just under a hundred years ago.  Give this a look: [Anton Parr]     What is advertised is the Kinematic viscosity (mm2/s) or that which has been density adjusted but the value we are after is the dynamic viscosity (mPa.s) or true viscosity. You can see that this number is dependent on density thus base stock and temperature. You can also see that an SAE 30 doesn't reach that value in this example. However an SAE 30 that is at the upper end of the SAE 30 range; 12.5 cSt (mm2/s), might. 12.5 * .83 = 10.375 (mm2/s). If you could find an SAE 30 at the upper end these days.   Then there is the complication of viscosity modifiers or VII or VM, whatever you wish to call them. Polymers added to very thin base oils, perhaps 3 to 6 cP oils, that will meet the SAE *W30 spec at 'tested' shear rates and 100 C/212F  target temperature. So a polymer fortified base that is a fraction of the 10 cP requirement Stribeck insist upon.   This could be all well and good if those polymers didn't have two very problematic 'features'. They shear or loose viscosity both 1.) permanently and 2.) temporality. And they do both omitted in the advertised data with the distinct  purpose of deceiving the consumer of the actual operating state of the fluid. I've shown the example of Warren Oils COSTCO 10.91 cSt 5W30 formuation several times where the 100 C HTHS value is 6.9 cP!! That's the temporary shear down and with and SSI or shear stability index of 9.4 cSt. Note the intentional deception in using mixed units?    After a short while that 9.4 cSt oil has a viscosity corrected dynamic value of 7.8 cP. But as the SSI is still within the range of an SAE *W30 whose lower value is 9.3 cSt.    This allows them to continue to call this SAE 16 weight oil a 30 weight, the cake, and still meet the API requirements for fuel efficiency IMPROVEMENT mandated by the EPA. The eating of the cake. By the time you've worn out your motor doing the responsible thing by adhering to the warranty requirements, (the stick), you get deprived of the carrot, wear control. So sad, to bad.   So what can be done? Do I need actually say? [Anton Parr]       Even this must be monitored if the oil is on the low side and the VII an organic or you opt for a 0W40 with an even lighter base oil and more / higher MW VII. (Note the lower density of the 40 weight versus the SAE 30 mono-weight?)    There is another workaround. Temperature. An SAE *W30 run at a bulk temperature of between 180 and 195 F.    Being the belt and suspenders sort I am I do both. Run it cook and run it heavy.    In Part II I'll work the AW package. 
    • 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.      

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...