Torsion bars

[Steven Petersen]

I have an 88 K2500 light duty/6 lug. When I bought last year from the original owner the torsion bars were cranked way up. I lowered them down to factory Z-height. The pickup rides better but still not as soft as the 88 K1500 i used to own. Did these light 3/4's have stiffer bars than the 1/2 tons? I really only wanted the 3/4 since it had the 9.5" rear end.

 

[stutaeng]

I believe the 2500 6 lug suspension is the same as the 1500, with the exception being rear axle and leaf springs. Therefore, your torsion bars should be the same as the 1500. @someotherguy has plenty of knowledge on these trucks...

Do you have LT-series tires? Maybe that's why it riders stiffer?

 

[Steven Petersen]

I believe the 2500 6 lug suspension is the same as the 1500, with the exception being rear axle and leaf springs. Therefore, your torsion bars should be the same as the 1500. @someotherguy has plenty of knowledge on these trucks...

Do you have LT-series tires? Maybe that's why it rider stiffer?

Yes it has LT265/75/16. But I'm pretty sure that's what I used to run on my old one too.

 

[someotherguy]

I believe the 2500 6 lug suspension is the same as the 1500, with the exception being rear axle and leaf springs. Therefore, your torsion bars should be the same as the 1500. @someotherguy has plenty of knowledge on these trucks...

Do you have LT-series tires? Maybe that's why it riders stiffer?

The 2500 "light duty" shares a lot of chassis with a 1500, but I would assume (do not know for fact) that it would have higher rate torsion bars than a 1500 - to match the higher rate (known fact) rear spring pack. They generally engineer these types of things as matched packages. The GVWR being higher pretty much necessitates higher spring rates, better brakes, better differentials, etc. The frame is a 1500 frame with a few minor extra braces/gussets. They appear insignificant at first glance but surely some engineers at GM did the math on what they add to the overall package, or these differences wouldn't exist.

Richard

 

[Steven Petersen]

The 2500 "light duty" shares a lot of chassis with a 1500, but I would assume (do not know for fact) that it would have higher rate torsion bars than a 1500 - to match the higher rate (known fact) rear spring pack. They generally engineer these types of things as matched packages. The GVWR being higher pretty much necessitates higher spring rates, better brakes, better differentials, etc. The frame is a 1500 frame with a few minor extra braces/gussets. They appear insignificant at first glance but surely some engineers at GM did the math on what they add to the overall package, or these differences wouldn't exist.

Richard

From the 88-89 Parts book. There’s 4 different torsion bars available on 1500’s. And 5 that were available on 1500, 2500 and 3500. So all 9 were available on 1/2 tons.

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[Steven Petersen]

I figured out I have the GG bars. I wonder if switching to lower torque bars would improve the ride? I also wonder why GM offered so many different choices. What determined which bars a particular vehicle was equipped with?

 

[Aparke4]

I figured out I have the GG bars. I wonder if switching to lower torque bars would improve the ride? I also wonder why GM offered so many different choices. What determined which bars a particular vehicle was equipped with?

Snow plow package, fleet or gov't use, turbo diesel 6.5 added weight, 7.4 big block added weight, extended cab versions = more weight that standard cab truck, work truck packages and more... there were so many applications for the OBS trucks over the years and variants hence the changes in torsion bars as the GVWR/ GCWR for each package changed and therfore updates were needed regarding towing and payload.