Towable RV · Towing 101 guide
A weight-distribution hitch (WDH) is the safety device that redistributes a trailer's tongue weight across the tow vehicle's axles and the trailer's axles. Mandatory for trailers over approximately 5,000 lbs in most cases.
When a trailer's tongue applies downward force on the tow vehicle's hitch, it presses the rear axle down and lifts the front axle. This degrades steering, braking, and headlight aim.
WDH uses spring bars between the trailer's A-frame and the tow vehicle's receiver to apply leverage that restores weight to the front axle.
Result: the tow vehicle handles closer to its unloaded condition. Steering is precise, braking is effective, headlights point correctly.
Trailers over approximately 5,000 lbs GVWR — required by most tow vehicle manufacturers.
Combined trailer + tow vehicle GCWR exceeding 14,000 lbs — typically required.
Heavy fifth-wheels do NOT use WDH (the fifth-wheel's pin weight rides over the tow vehicle's rear axle, not behind it).
The trailer's manufacturer typically specifies WDH requirement in the trailer's owner's manual.
Step 1: park tow vehicle on level ground, measure front axle height (top of wheel arch to ground).
Step 2: couple the trailer to the tow vehicle, measure front axle height again. Difference is the 'squat'.
Step 3: adjust WDH spring bars to restore approximately 50% of the squat (industry rule of thumb). Some setups recommend restoring 100% of squat — verify with the trailer manufacturer.
Step 4: re-measure to confirm. Adjust if needed.
Some WDH systems include integrated sway control (Equal-i-zer brand uses cam-action sway resistance).
Other WDH systems require a separate friction-bar sway control (Reese Dual Cam, Husky Centerline).
Best practice: WDH + sway control is the safe pairing for any trailer over 5,000 lbs. Many premium WDH systems combine both.
Most PickRV travel trailer rentals over 5,000 lbs GVWR include the WDH and sway control hardware. The listing tells you which.
If WDH is required but not included, the renter must provide. The host's pre-trip inspection verifies the hitch and WDH are properly installed and adjusted.
Hosts walk renters through WDH adjustment at pickup. Adjustment is not difficult; it requires patience and the right tools (typically a torque wrench for spring-bar nuts).
Sources cited (SAE / FMCSA / industry)
FAQs
Not federally mandated. Required by most tow vehicle and trailer manufacturers for combinations over 5,000 lbs. Manufacturer non-compliance may void warranty or insurance.
Possibly, depending on tow vehicle and tongue weight. Many half-ton trucks pulling a 4,800-lb trailer benefit from WDH even if not technically required. The host advises.
Once set per trip is typical. Adjustment may be needed if you change cargo loading (e.g. shift heavy gear in the trailer) or change tow vehicle.
Verify your tow vehicle can pull this trailer before you book.
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