What is Best Rear Suspension Enhancement for 2026 GMC Sierra 3500 Denali Towing 5th Wheel Camper

Updated 01/21/2026 | Published 01/19/2026

Products Featured in This Question

RoadActive Suspension Custom Leaf Spring Enhancement Kit - Heavy Duty

(636)

$589.00

Timbren Suspension Enhancement System - Severe Service - Rear Axle

(966)

$398.07

Question:

Hello, I have a 2026 GMC 3500 Denali Ultimate pickup, and a 2023 Grand Design Solitude 310GK 5th wheel RV, which has about 3500-4000 of pin weight when loaded right at my maximum payload. Previously I had a 2023 GMC 3500 Denali, and I installed the Timbren TGMRTT35DD bump stops. They did an excellent job of leveling the truck and keeping it very stable when towing the RV. I was quite happy with the towing performance but they did shorten the travel of the rear suspension quite a bit, and when not towing, the rear suspension would bottom out if I hit a deep rut or steep bump. Are these Timbrens the best solution for my needs, or might there be another better solution? Thank you for your expert advice! Joe

asked by: Joe P

Expert Reply:

Hey Joe, we have just what you are looking for with the Roadactive Suspension Kit part # RAS3611-CHD. This will give you the additional suspension support you are looking for without hurting your unloaded ride quality. This will actually improve ride quality loaded and unloaded as well as improve handling for both as well. The install is easier and there's no air pressure to monitor like air bags so it's really the best all around. How often are you out with your Grand Design?

expert reply by: Jameson C

Joe P.

1/21/2026

Hmm. I read many of the reviews, and it seems the Roadactive kit will raise the bed when unloaded. Not sure I want my truck raked forward 95% of the time, since I only use my RV a few times a year. Also not sure these will provide enough support with 4000 lbs of pin weight. I think I'll stick with the Timbrens and just deal with the occasional bottoming out. I had them on my last truck and it was rock solid when towing. Thanks for your help! Joe

Dan C.

1/21/2026

@JoeP I manage a fleet of 2500s and 3500s and the 3500 could use some Timbrens, as I towed with it recently, 10,000 or so, but other than that, great in the wind. My primary is a 2022 2500 gas, and I have Timbrens and RAS. Ran Timbren only for a few years, but the RAS makes my 2500 solid like the 3500. Diesel purchase soon…… Can’t run RAS on 3500, without removing the overload springs, which the Timbrens will help the “hard knocks” from bottoming them out. Easy install. Jacked up the hitch and stretched the suspension and crawled under. Large flathead, pop out the old ones, put the Timbren in as tight as you can, place a block of wood under the T and the axle, drop the hitch, make sure it’s seated, take the wood out. Boom.

Jameson C.

1/21/2026

@JoeP That will depend on how much spring tension you put in the RAS kit. If you crank it down it will raise the rear suspension a bit but nothing too crazy. I have two friends who have this kit and they don't have any lift but it's still enough support to make a difference. That said if you liked your Timbrens in past and know what they are like then that would be the way to go.