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Hauling gear, towing a trailer, or loading up for a trip can make your rear suspension work overtime. These Coil SumoSprings helper spring inserts slip between the coils of your existing springs to boost support and keep your ride level under load. Each spring has an inner core made from microcellular polyurethane foam that cushions the suspension and reduces harsh jolts when the weight piles on. The more you load onto your vehicle, the stiffer they become—so you get progressive support exactly when it’s needed.
Rear-end squat can throw off handling, steering, and braking when towing or carrying heavy cargo. The Coil SumoSprings helper springs increase your suspension’s ability to support weight, helping to keep things level and stable. The progressive design reacts to how much load you’re carrying, firming up as weight increases to cut down on body roll and sway without making the unloaded ride harsh.
Unlike air springs that rely on air pressure, tanks, or valves, these polyurethane inserts require no monitoring or upkeep. Just position them between the individual coils of your rear coil springs and you’re done—no hoses to route or fittings to install. Once in place they quietly go to work every time you hit a bump or add cargo, giving you consistent support with zero maintenance.
Road salt, oil, UV rays—these conditions can wear out lesser materials fast. Each Coil SumoSpring is crafted from durable microcellular polyurethane that resists abrasion and damage from heat or chemicals. They hold up through extreme temperatures and heavy use so you can depend on them season after season without worrying about leaks or breakdowns.
Installing this kit doesn’t require special tools or professional help. The wedge-shaped inserts are custom sized for a precise fit on rear coil spring suspensions that are already in good working order. Just lift the vehicle enough to extend the coils, slide the helper springs into place, and head back out on the road knowing your suspension has extra support ready for whatever load you throw at it.
Customer Satisfaction Score:
95% were satisfied with this product
5% of customers were not satisfied
Ratings & Reviews
Lodwik
9/25/2025
After 12 months is works great to lift the backend of 34 ft rv when parking And more stable when driving
Kate F.
2/5/2026
I completely understand why this was frustrating, David. You’re right that the 2WD and AWD SumoSprings look almost the same. The difference isn’t in how they wrap the spring, but in their height and when they engage. AWD Highlanders sit slightly higher in the rear, so the AWD version is taller to work correctly under load, even though it may not meet in the middle of the coil. What are you hauling around that you needed the extra support?
Scott
7/7/2025
Still glad I have used these springs over the past year of towing. I could almost use a set that is just a little bit stiffer but still way better towing with them for sure!
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Justin G.
1/8/2015
They are great! Big difference from stock.