Axle Flip Kit for 2021 Forest River Salem FSX 181RT

Updated 07/13/2025 | Published 07/10/2025

Products Featured in This Question

Dexter Trailer Springs Over-Under Conversion Kit

(817)

$80.32

Dexter Trailer Springs Over-Under Conversion Kit

(817)

$95.95

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

(310)

$267.99

Question:

Hi I’m looking to flip the axle on my 2021 forest river Salem FSX 181RT. It’s got cambered axles so I was wondering if you had a hardware kit with axle perches that are cut right so I can just weld them on. Also it looks like the springs are soooooo short I was wondering if it wouldn’t be a good idea to put new perches and longer springs in to give it a little more cushion off road

asked by: Cody W

Expert Reply:

Hi Cody; all of your standard axles like what you have on your 2021 Forest River Salem FSX 181RT have a slight bend in them so that is nothing unusual. The best option for a flip kit is going to be the Dexter Trailer Springs Over-Under Conversion Kit # K71-384-00 (2-3/8" diameter axles) or # K71-385-00 (3" diameter). You can bolt these on but it is recommended to tack weld them in place.

I do not recommend adding longer leaf springs to the trailer. If you leave your hangers as they are and add longer leaf springs you're going to run into problems you don't want. I also wouldn't try to move the hangers to add longer springs since you'll likely throw off the geometry. The trailer was designed that way for a reason.

If you want to add some off-road cushion you're better off adding something like the SumoSprings Trailer Helper Springs # TSS-107-40. These absorb road shock, reduce body roll, and compensate for off-center loads like heavy kitchens and slide-outs which will be helpful both on and off the road. You will need a pair for each axle.

What kind of off-road places are you taking your trailer? Any big trips planned this summer?

expert reply by: Robin H

SumoSprings Trailer Helper Springs
(click to enlarge)

Cody W.

7/13/2025

Thanks, Robin. I’ll look at those flip kits. I’m comfortable moving hangars and eyes if that makes a difference…we have a full fab shop I’m just not versed in choosing spring rates and figuring out the ideal shackle angle and length. Also is there a shock kit you offer? I don’t really need any help with load since it’s a light trailer and no slides or anything, just want to kill as much vibration as I can. The washboard just rattles these trailers apart. I know the shocks come in different damping coefficients I just don’t know which ones I should be looking for and at what angle they should be mounted at

Robin H.

7/13/2025

@CodyW yeah I still wouldn't try and move them even if you're comfortable with that kind of work. You could add a shock kit like the Roadmaster Comfort Ride Shock Absorbers # RM-2450. Do you have 3,500 lb axles? That is what these are designed for. I always forget about shocks but they're probably a better solution for what you're wanting. Their instructions lay it all out nicely and show how to determine the shock angle.

Helpful Links

instructions.aspx?pn=rm-2450