sultastic spring shackles

anthonybehnken · December 6, 2020

Has anyone had any experience with the Sultastic spring shackles ?

Grumpy Bear · December 6, 2020

Yes. Have them on my 1500. When they wear out I'll buy another set.

Takes the bite out of that first inch of wheel travel.

dasbill · March 6, 2022

Have them on my 2020 GMC 3500 SRW and like the guy above said. If they wear out I will be purchasing and installing back on my truck. These make a huge ride quality difference in 2500 and 3500. No filling rattling bumps. Really smooths the bumps out.

MTU Alum · March 6, 2022

I would add they are not good for on center steering. It creates a larger deadban on center and slower steering response off center.

GMC4Zee · January 6, 2023

MTU, how can a rear spring mount change steering response? Grumpy bear, does the addition of these new mount affect towing at all? I am thinking I may get more squat when I hook up the 5th wheel? Are these installable by the average owner or is a lift needed?

MTU Alum · January 7, 2023

Shackles has one of the biggest influence on lateral stiffness in rear suspension. These aftermarket shackles have lower rates than production so they ride great but the tradeoff is steering performance and handling when unloaded. The steering gets heavier and more vague on center.

Grumpy Bear · January 8, 2023

On 1/6/2023 at 5:48 PM, GMC4Zee said:

MTU, how can a rear spring mount change steering response? Grumpy bear, does the addition of these new mount affect towing at all? I am thinking I may get more squat when I hook up the 5th wheel? Are these installable by the average owner or is a lift needed?

First if you put a @ before a person's as written handle, they will get the tag. Surprised I even saw this.

Never towed a thing so I can't say. Lift is handy be not required. If the bolt won't clear use a cut off wheel and install the new from the opposite side. I had to do neither.

Not towing, I can say I found zero transition response issues @MTU Alum alluded to. IF I did tow and it showed up or it was an issue not towing then I would have added a Panhard Rod to negate it and kept the ride quality. These things ride like crap stock because the fix cost money that eats profits. You accepting that is up to you. I choose not to. Panhard Rod Kit - Maier Racing

Edited January 8, 2023 by Grumpy Bear

asilverblazer · January 9, 2023

I guess I wasn't as impressed as everyone else... I had them on my 1/2 ton, and the truck rode well. I added the shackles at the same time as I installed new shocks. The two improved ride maybe 10%. The ride was never harsh, I never had any kind of sway problems when towing.

I would add them again IF the cost was about 1/2 what they sell for. They worked - but just weren't worth the price to me.

asilverblazer · January 9, 2023

On 1/7/2023 at 12:07 PM, MTU Alum said:

Shackles has one of the biggest influence on lateral stiffness in rear suspension. These aftermarket shackles have lower rates than production so they ride great but the tradeoff is steering performance and handling when unloaded. The steering gets heavier and more vague on center.

Not disagreeing with your logic - but the results you describe simply didn't materialize at all in my truck, loaded heavy, loaded light, unloaded.