Best Helper Springs for a 2015 Thor Four Winds with Rear Sag

Updated 06/24/2026 | Published 06/22/2026

Products Featured in This Question

Hellwig EZ-990 Helper Springs - Above Axle

(120)

$171.73

SuperSprings Custom Suspension Stabilizer and Sway Control Kit

(308)

$652.99

Question:

I have a question about helper springs. I have a consistent load that I just need to bring up. My current springs are bowed upwards .! I just need something to give me a little more lift in the rear end and remove the sag.

asked by: Billy W

Expert Reply:

Billy, if you're carrying a constant load and the rear of the vehicle is sagging, helper springs are worth considering.

On a heavily loaded Ford E-350 or E-450 chassis which is the most common chassis for the Thor Four Winds, it's common for the factory leaf springs to flatten out over time, and if they've developed a noticeable upward or inverted bow, that can be a sign that they're carrying more weight than they were originally designed to support. That is something to keep an eye on. I should also mention that Hellwig does not currently offer a helper spring setup like part # HE48VR specifically designed for the Thor Four Winds, so I recommend taking a look at SuperSprings.

For a setup like that, I typically recommend looking at SuperSprings. They work alongside your existing leaf springs to help restore ride height, reduce sag, and improve stability without the maintenance that comes with air bags. They're especially popular on motorhomes because they help reduce body roll, improve handling in crosswinds, and provide support for the constant weight these vehicles carry.

The exact SuperSprings kit depends on your specific Four Winds model and chassis. For example, the SuperSprings Custom Suspension Stabilizer and Sway Control Kit part # SSA47 fits certain 2015 Thor Four Winds models built on the Ford E-Series chassis, but I'd want to confirm your exact floorplan and chassis before recommending a specific part number.

What model Four Winds do you have, and what's the steady load you're carrying back there, travel gear, tools, a camper setup, or something else?

expert reply by: Heather A