Suspension Enhancement Options for 2021 Salem FSX 178BHSKX With Single Underslung Axle

Updated 06/30/2023 | Published 06/28/2023

Products Featured in This Question

SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Underslung

(65)

$299.99

Dexter Trailer Springs Over-Under Conversion Kit

(787)

$82.57

Dexter Trailer Springs Over-Under Conversion Kit

(788)

$92.50

Lippert Bolt-On Shock Kit w/ Heavy Duty Gas Shocks - 3,500-lb (2-3/8") Axle

(81)

$184.17

Lippert Bolt-On Shock Kit w/ Heavy Duty Gas Shocks - 5,200-lb to 7,000-lb (3") Overslung Axle

(81)

$228.89

Timbren Trailer Suspension Enhancement System for Underslung Axles - 5,000 lbs

(1)

$398.07

SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung

(306)

$267.99

Question:

I have a 2021 Salem FSX 178BHSKX single axle with Dexter 4400# underslung leafs under the axle suspension. I was looking at the TSS-106-40 Sumo Spring kit but only have about 5.5 inches from the frame rail to the top of the leaf spring. If I do not use any spacers will I be able to use this SS kit? I do have Sumos on my Nissan Frontier and they work great for reducing squat when I tow. Im hoping this kit will helps smooth out the ride and reduce suspension wear since the 4400 axle is right at the top of the weight rating for this camper.

asked by: Rick G

Expert Reply:

According to SumoSprings, 6" is the minimum for the # TSS-106-40. I asked them about this and they said you cannot use these if the space is under 6" so unfortunately they won't work for you. Doing so will overload the springs which can cause damage to the trailer and make the ride bouncy instead of smooth.

With that amount of space and the single axle you're pretty limited on options for suspension enhancement. If you really want to use the SumoSprings you could cut off your existing hangers and weld on taller hangers so you have more space. Another option would be the Timbren # T92MR. However, this is 5-1/4" tall so it will barely fit. Timbren springs are also pretty stiff so I don't think you will be happy with the end result.

The other option I have would be to flip the axle so it is overslung and then add shocks. You could try to measure to see if the # TSS-107-40 would fit after flipping the axle. More than likely it won't since the underslung springs wouldn't. You would need to choose the correct kit based on your axle diameter. More than likely it is 2-3/8" and you need the # K71-384-00 but if it is 3" you need # K71-385-00 instead. Keep in mind, this will also raise your trailer by the diameter of the axle plus the height of your leaf spring stack.

Once the axle is flipped, you can use the Lippert Bolt-On Shock Kit. Once again you will need to choose the correct kit based on axle diameter. If you have a 2-3/8" axle you need # LC281255 and for a 3" axle # LC281281. This will help smooth out your ride for a better towing experience.