Promaster SumoSprings Rear Helper Springs

$ 284.99

Promaster rear SumoSprings or helper springs for van and cab chassis, 1500, 2500 and 3500. Great for the Trend, Zion SRT, or any motorhome. This is the same product that is now coming stock on the Winnebago Travato. Also great for contractor vans or any loaded Promaster van. Sold in pairs. Adjustable length allows flexibility for fine tuning. Each side will have two 1" spacers which will make the product 6.5 inches or 7.5 inches in length depending on spacers used. This allows you to have the SumoSprings engage more by using both spacers or less by using one.

The Promaster SumoSprings can help reduce side to side movement, sway, and rocking. No modifications or drilling are needed. They mount using your factory bump stop brackets. Unique double spacer mount included to fine tune your rear suspension. Use one spacer for less engagement or the double spacer for more engagement. The Promaster SumoSprings come in a heavy duty version for heavy cargo and RV use, a medium duty version for light van conversions, medium cargo use, and a light duty version for passenger vans or lightly loaded vehicle . You will see those options at check out.

SumoSprings are a micro cellular urethane product designed to enhance load carrying ability and stabilize sway. They can also help decrease and cushion hard bottoming of the factory springs on vehicles that are at or near their weight capacity. These springs are a progressive system that increase load holding capacity as the product compresses. Soft riding with easy installation and no maintenance. They work much like an air bag system, but with thousands of tiny air bubbles that never leak out.  Helps with both jounce and rebound as they absorb energy on compression. Do not exceed GVWR for your vehicle. 

 Promaster SumoSprings video - installation tips - click here


  • Sold in pairs
  • 6 to 7 inches in length depending on whether you use one 1" spacer or both - there are two 1" spacers included in the kit
  • Product capacity is 1000 lbs at 50% compression for the light duty material - blue
  • Product capacity is 1500 lbs at 50% compression for the medium duty material - black
  • Product capacity is 2800 lbs at 50% compression for the heavy duty material - yellow
  • Read all manufacturers recommendations and warnings 
  • All warranties are manufacturers' warranties
  • Never Exceed Gross Vehicle Weight Rating


Clear instructions are included, and full tech support is always offered. Call anytime with questions or orders 971-678-5940.