Product Description
Comfort Ride Slipper Spring Third Axle Kit
Most trailers have two axles and are known as tandem axle trailers. Comfort Ride Slipper Spring kits include enough parts for a typical tandem axle trailer. But many larger, higher end trailers and fifth wheels use three axles and are known as triple axle trailers. The kits listed below contain the components for a third axle only.
If installing Comfort Ride Slipper Springs on a triple axle trailer, you will need one tandem axle kit AND one third axle kit. The two kits combined provide all the components for three axles.
Why doesn't Roadmaster offer one box with everything you need for 3 axles? Logistics. With all 6 leaf springs the kit would weigh approximately 180 lbs. This makes a single box too heavy to ship via small parcel. To prevent the extra cost of shipping by LTL freight truck, Roadmaster sells the third axle kit separately. The two boxes can both be shipped small parcel.
The 2503-60 is a Third Axle Slipper Spring system for up to 5,000-pound rated axles.
The 2503-66 is a Third Axle Slipper Spring system for up to 6,000-pound rated axles.
The 2503-70 is a Third Axle Slipper Spring system for up to 7,000-pound rated axles*.
The 2503-80 is a Third Axle Slipper Spring system for up to 8,000-pound rated axles*.
Use a slipper spring kit that is rated higher than the loaded weight of the RV, regardless of the axle capacity. For example, if a trailer has two 7k axles (total of 14k), but its loaded weight is 14,400 lbs., then use the 8k kit instead for a total capacity of 16k lbs. Using springs rated less than the loaded trailer weight will result in non-warranty damage to the springs. For more information about which capacity springs are appropriate for your trailer, see frequently asked questions below.
Important: You must order a tandem axle kit AND a 3rd axle slipper spring kit in order to have all the components for a triple axle installation. Both kits must be for the same weight rating.
How do I find axle measurements?
Need a Comfort Ride Shock Absorber for a third axle?
Add a Comfort Ride Shock Absorber system
Note: Not all components are made in the US.
Comfort Ride Slipper Spring System – FAQ
Q: What is the Comfort Ride Slipper Spring System?
A: The Comfort Ride Slipper Spring System is a complete trailer suspension upgrade that replaces the factory equalizer and leaf spring setup. It includes a slipper spring box, upgraded slipper-style leaf springs, and is designed to be used with Comfort Ride shock absorbers for optimal performance.
Q: Does installing lower-rated springs (e.g., 7K) void the warranty if the axle is rated higher (e.g., 8K)?
A: No. Our warranty is based on the actual load carried on the axle, not its maximum rating. As long as the spring’s rated capacity exceeds the real-world load, the system remains under warranty—even if the axle itself is rated higher.
Q: What happens if I install springs that are rated much higher than the load they carry?
A: Your trailer will ride harshly. Think of a 1-ton truck driving empty—it’s stiff and uncomfortable. Oversized springs won’t compress effectively under lighter loads, meaning the suspension can’t absorb road bumps. This results in a rougher ride and greater stress on the trailer’s frame, walls, and seams, potentially causing long-term damage. It also increases “push-pull” behavior, making it harder to maintain control between the lines. Ideally, choose the lowest-rated spring that still exceeds the maximum axle load. We recommend visiting a truck scale with your trailer fully loaded to determine real axle weights.
Q: Does this system work with fifth wheels?
A: Yes. Just remember that a portion of the fifth wheel’s weight (the pin weight) is carried by the truck, not the trailer’s axles. Therefore, choose springs based on the actual axle load, not the full trailer weight.
Q: For triple-axle trailers, why do I need to order a tandem axle kit and a third axle kit? Why not one all-in-one kit?
A: Weight and shipping constraints. A complete triple-axle kit weighs over 150 lbs and cannot be shipped via standard parcel services like UPS or FedEx. Shipping as freight would be costly. Even if shipped via UPS, handling a 170 lb box isn’t practical. Separating it into two manageable kits allows for standard shipping and easier handling.
Q: What if the trailer has an unusual hanger layout or offset mounts?
A: Some trailers use offset or boxed hangers that may not support a standard installation. In those cases, the installer may need to fabricate a new mounting surface or remove the factory hangers, which are sometimes riveted to the frame. These modifications require advanced fabrication skills. Always send photos to your dealer or installer in advance.
Q: Do I need to install the Comfort Ride shock absorbers as well?
A: Yes. The slipper spring system is designed to work with Roadmaster’s Comfort Ride shock absorbers. While installing the springs alone is an improvement, the combined system offers a significantly better ride and longer trailer life. If you can only install one, Roadmaster recommends prioritizing the shock system.
Q: What’s the main benefit of the Comfort Ride system?
A: It improves ride quality, reduces bounce, and absorbs road impact more effectively. When paired with Comfort Ride shocks, it delivers a dramatically smoother, safer towing experience and minimizes wear on both your trailer and tow vehicle.