Recommended Rear Suspension Enhancement for a 2021 GMC Sierra 1500 AT4
Updated 03/26/2023 | Published 03/25/2023
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Question:
Will part number SS45MR fit a 2021 GMC Sierra 1500 AT4?
asked by: Ryan
Helpful Expert Reply:
There is a set of SumoSprings that fit your 2021 Sierra 1500 AT4 but item # SS45MR do not fit. The ones that fit are item # SS45FR. These have a slightly lower capacity at 1,500 lbs but will fit so long as your truck doesn't have the adaptive ride control option. I have a completely different system I would recommend you use. Since your 1500 AT4 has a 2" lift from the factory, SumoSprings will not be the best way of supporting your truck's rear suspension. The kit comes with a 1" spacer which would work fine with a small lift but anything past 1" in the rear would render the system ineffective. You would have noticeable sagging before the SumoSprings engage.
Instead, I recommend the RoadActive Suspension Custom Leaf Spring Enhancement Kit item # RAS4611. The RAS system attaches to your factory leaf springs, turning them into a mechanically active suspension system. These can be adjusted based on how much support you want while towing or carrying a heavy payload. Once set up the coil tension springs automatically adjust to your truck's load, activating immediately to support the extra weight.
I have linked a couple of installation videos below. Feel free to email me back if you have any other questions.
Product Page this Question was Asked From
SumoSprings Solo Custom Helper Springs - Rear Axle
- Vehicle Suspension
- Towing/Load Leveling
- Bump Stops
- Suspension Only
- Standard Duty
- Rear Axle Suspension Enhancement
- SuperSprings Intl
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