How to tell if a weight distribution hitch is working

A weight distribution hitch (WDH) is working when it restores front-axle load/ride height toward your unhitched baseline (typically to within about 0–0.5 in of the original front fender height or 50–100% front-axle load restoration per SAE J2807/manufacturer guidance), the outfit sits level, steering and braking feel natural, and the spring bars or tension elements are properly loaded without clearance issues; you can verify this with quick measurements, a brief road test, and—best of all—a trip across a scale. This article explains practical checks, measurements, and adjustments to confirm correct WDH performance and troubleshoot problems.

What a WDH should do

A WDH uses spring bars or tension elements to transfer a portion of the trailer’s tongue weight from the tow vehicle’s rear axle to its front axle and to the trailer axles. When correctly set, it reduces front-end lift from hitching, restores steering and braking authority, keeps headlight aim closer to level, and often calms fore–aft “porpoising.” Some systems include built-in sway control, but weight distribution alone does not cure every sway issue—proper tongue weight, loading, speed, and tires still matter.

Quick checks before you roll

Before measuring or road testing, a few visual and fitment checks can quickly signal whether the hitch is engaged and set up plausibly.

• Spring bars or tension elements are visibly under load (deflected or tensioned) and sit roughly parallel to the trailer A‑frame or per your model’s instructions.
• Correct chain link count or L‑bracket contact: tension points are even side to side, with enough clearance in turns and bumps.
• Hitch head and shank hardware torqued; pins and safety clips installed; coupler fully latched and locked.
• Bars and brackets have adequate ground clearance when level; no contact with tongue jack, propane trays, or A‑frame during sharp turns.
• Integrated sway-control elements (friction pads, cams, or cones) are installed and adjusted per the manufacturer’s spec.

If these basic conditions are met, the system is likely engaged correctly, setting you up for more precise verification steps.

Measure performance: the tape-measure method

You can confirm effective weight distribution with a tape measure on level ground by comparing fender heights before and after hitching and after engaging the WDH.

1. Unhitched baseline: With only the tow vehicle (TV), measure from the ground through the wheel center to the top of the front and rear fenders; record values.
2. Hitched, no WDH: Couple the trailer but leave the WDH disengaged. Measure front and rear again; the front usually rises and the rear drops.
3. Hitched, WDH engaged: Apply your normal WDH tension (bar angle/links/L‑brackets). Measure front and rear once more.
4. Evaluate the front height: Many manufacturers aim for the front to return to its unhitched height, typically within about 0–0.5 in (0–13 mm). Avoid going lower (front fender significantly lower than unhitched) unless your vehicle maker specifically allows a small amount; over-distribution can degrade ride and traction.
5. Adjust as needed: Increase bar tension (more head tilt, fewer free chain links, or more L‑bracket pressure) if the front is still too high; decrease if the front falls below the unhitched height or ride becomes harsh.

This method closely mirrors OEM guidance and quickly shows whether you’re restoring the front axle load and attitude toward factory intent.

Confirm with scales (best practice)

For the most accurate check, weigh the rig on a certified scale (e.g., a CAT Scale) and compute front-axle load restoration (FALR). This directly shows the WDH’s effect on axle loads.

1. Pass 1 — Tow vehicle only: Record steer axle and drive axle weights (and total).
2. Pass 2 — Hitched, WDH off: Couple the trailer but leave the WDH slack. Record steer, drive, and trailer axle weights.
3. Pass 3 — Hitched, WDH on: Engage the WDH at your target setting. Record weights again.
4. Compute FALR: (Steer_Weight_WDH_On − Steer_Weight_WDH_Off) ÷ (Steer_Weight_Unhitched − Steer_Weight_WDH_Off). Target is often 50–100% per SAE J2807 and many OEMs, without exceeding the unhitched front axle load.
5. Verify limits: Ensure no axle exceeds GAWR, the receiver and hitch ratings (including tongue weight with cargo and water) aren’t exceeded, and trailer axle load increases appropriately with WDH engaged.

If your FALR target is met and axle weights are within ratings, your WDH is performing as intended; adjust tension if you’re below target or over-restoring the front axle.

Road-test indicators

A careful road test at moderate speed confirms dynamic behavior. Find a safe, low-traffic route and observe feel and responses.

• Steering feels planted and consistent; no light, floaty front end.
• Braking remains stable with no pronounced nose lift or push from the trailer.
• Reduced fore–aft pitching over bumps and dips compared with WDH off.
• Headlight aim appears correct; no obvious glare from front lift.
• Crosswind and passing-truck effects are manageable; minor sway self-corrects without constant input (assuming proper tongue weight and tire pressures).

These cues, combined with your measurements, provide a reliable confirmation that the hitch is doing its job in real conditions.

When it’s not working: red flags and fixes

If measurements or driving feel are off, the following symptoms help pinpoint issues and the typical adjustments that resolve them.

• Light steering/front lift: Increase WDH tension (more head tilt; use fewer free chain links or more L‑bracket load); verify correct spring-bar rating for your actual tongue weight.
• Front lower than unhitched or harsh ride: Reduce WDH tension; ensure you’re not exceeding the vehicle maker’s guidance for front height/axle load.
• Persistent sway: Check tongue weight (aim about 10–15% of trailer weight for most travel trailers), load heavy items forward of the trailer axle, verify tire pressures (trailer tires typically at sidewall max cold), reduce speed, and ensure sway-control components are engaged and correctly adjusted.
• Porpoising/bounce: Fine-tune WDH tension, verify shocks and rear suspension condition, and redistribute cargo to avoid excessive rear bias.
• Interference or low clearance: Adjust head height/tilt, increase the number of free chain links for clearance (if applicable), or change shank drop/rise to level the combo.
• Uneven side-to-side: Re-check bar engagement or bracket positions; cargo may be off-balance; adjust to equalize left/right tension.

Addressing these items typically restores proper distribution and stability; if problems persist, consult the hitch and vehicle manuals or a professional hitch installer.

System-specific notes

Different WDH designs have unique setup details. Checking these model-specific cues helps verify proper operation.

• Chain/snap-up bar systems: Keep adequate clearance—many setups need at least five free chain links between the bar’s U-bolt and the hanger. Tension is set by head tilt and which link you snap up.
• Round-bar vs. trunnion-bar: Bars should run level to slightly downward toward the L‑brackets or chains when loaded. Trunnion bars often offer better ground clearance.
• 4-point friction systems (e.g., Equal-i-zer): Bars must firmly contact the L‑brackets; do not lubricate the friction surfaces unless the manufacturer explicitly permits it. Torque bracket bolts to spec.
• Dual-cam systems (e.g., Reese Strait-Line): Cams should nest in the bar saddles on straight-ahead travel; chain length and cam arm position are critical to center the bars.
• Andersen-style (friction cone/chain): Verify nut torque and bushing compression per spec. These typically redistribute less weight than bar systems—use the scale method to confirm FALR.

Following the specific instructions for your hitch model is essential; design differences change how “correct” engagement looks and feels.

Safety and setup checklist

Correct operation depends on staying within ratings and confirming all connections and settings before each trip.

• Ratings: Receiver, shank, hitch head, and spring bars must meet or exceed actual tongue weight (with water and cargo) and gross trailer weight.
• Torque: Use a calibrated torque wrench on shank bolts, head bolts, L‑bracket fasteners, and any tension nuts as specified.
• Connections: Cross safety chains, attach breakaway cable to a separate point, and plug in the 7‑way; set brake controller gain with low-speed tests.
• Tires: Inflate trailer tires to sidewall max cold unless the manufacturer provides a load table; set tow-vehicle tires to the appropriate pressure for load.
• Clearances: Stow tongue jack fully, verify bar/bracket clearance in tight turns, and confirm adequate ground clearance.

Completing this checklist reduces the chance of handling problems and ensures your WDH can work as designed.

FAQ

These quick answers address common questions that arise when verifying WDH performance.

• How level should the rig look? Slight rear squat and a near-level trailer are normal; measurements matter more than looks.
• What if my truck’s manual conflicts with general advice? Follow your vehicle maker’s WDH guidance—it takes precedence over generic targets.
• Do I need sway control if I have a WDH? Often yes; many WDHs integrate sway control, but proper tongue weight, loading, and speed remain essential.
• How often should I re-check settings? Re-check after significant load changes, anytime towing feels different, and at the start of each season.
• What if my bars are the wrong rating? Undersized bars won’t restore enough front load; oversized bars can ride harshly. Match bar rating to actual loaded tongue weight.

Keeping these points in mind helps you quickly diagnose whether your setup is on target or needs attention.

Summary

Your WDH is working when objective measurements and driving feel line up: the front ride height or axle load is restored toward unhitched values (commonly within about 0–0.5 in of front fender height or 50–100% front-axle load restoration without exceeding unhitched), the combo sits near level, and control feels composed. Verify with tape-measure checks, confirm with scale weights if possible, and fine-tune head tilt and bar tension to meet your vehicle and hitch manufacturer’s specs.

Do weight distribution hitches make noise?

Weight distribution systems are prone to making some odd noises, but a sound that would wake that dead is probably on the higher than normal side of things.

How to properly set up a weight distribution hitch?

To set up a weight distribution hitch, you must first measure the truck’s uncoupled height, then couple the trailer to the tow vehicle, and finally attach the spring bars. The key is to use the trailer’s jack to raise the tongue, allowing for the easy installation of the heavy spring bars. After the bars are secured, the system’s components will distribute the trailer’s weight, returning the truck’s front-end height to nearly its original level for safe towing. 
1. Initial Measurements & Hitch Shank Setup

• Measure before connecting: With the trailer uncoupled, measure the height from the ground to the top of the front wheel well and record it. 
• Attach shank: Insert the adjustable shank (the piece that holds the hitch ball) into your tow vehicle’s receiver. The orientation of the shank will depend on your trailer’s height. 

This video shows how to attach the adjustable hitch shank into the receiver: 59sHomestead EngineeringYouTube · Aug 21, 2021
2. Couple the Trailer

• Lift the trailer: Using the trailer’s tongue jack, raise the coupler high enough for the hitch ball to pass underneath. 
• Position and couple: Back your tow vehicle into position and lower the coupler onto the hitch ball. Engage the coupler latch. 
• Support the weight: Leave the trailer jack engaged, supporting some of the trailer’s weight. 

3. Attach the Spring Bars 

• Grease connection points: Before insertion, add grease to the points where the spring bars connect to the hitch head. 
• Insert the bars: Insert the spring bars into the hitch head assembly. The method differs by hitch type; round bars are often inserted from underneath, while trunnion bars are angled in from the side. 
• Secure the bars: Use the trailer jack to raise the trailer tongue even further, which creates a gap between the hitch and the trailer’s frame, making it easier to install the spring bars. Once the bars are positioned, secure them with their designated clips or chains. 
• Final adjustment: The spring bars act like levers, pulling up on the back of the truck to transfer weight to the front end. 

You can watch this video to see how to attach the spring bars to the hitch head assembly: 1mCURTYouTube · Nov 19, 2013
4. Perform Final Measurements 

• Measure again: Opens in new tabOnce the spring bars are securely installed, perform the same height measurement on your vehicle’s front wheel well as you did in step 1. 
• Compare heights: Opens in new tabThe goal is for the front wheel well height with the bars installed to be very close to the initial measurement. The height should not have increased, and ideally, it should be within a half-inch to one inch of the uncoupled height. 

5. Test and Drive

• Check for stability: Test your setup on a flat, level area before hitting the road. 
• Consult manufacturer instructions: Always refer to the specific owner’s manual for your weight distribution hitch and tow vehicle for precise instructions and adjustments. 

How much weight does a weight distribution hitch reduce tongue?

A weight distribution hitch transfers about 70-80% of the original tongue weight back to the trailer’s axles and the tow vehicle’s front axle, effectively reducing the weight on the tow vehicle’s rear axle by 20-30%. It does not “reduce” the actual tongue weight but rather redistributes it, improving vehicle balance, handling, and safety by preventing rear sag and maintaining front-end stability.
 
How it Works

• Leverage: The spring arms of the weight distribution hitch create leverage, shifting weight from the tow vehicle’s rear axle forward. 
• Distribution: This shifted weight is then distributed between the tow vehicle’s front axle and the trailer’s axles. 
• Outcome: The result is a more level towing stance for both the tow vehicle and the trailer, which leads to better control while steering and braking. 

Important Considerations

• Not a Weight Reducer: Opens in new tabA weight distribution hitch does not lower the total tongue weight. It only changes how that weight is distributed across the vehicle and trailer setup. 
• Vehicle Ratings: Opens in new tabYou still must remain within your vehicle’s, trailer’s, and hitch’s weight ratings. 
• Trailer Frame Strength: Opens in new tabThe additional stress on the trailer frame from a weight distribution hitch should be considered, as some frames are not designed to handle the extra forces, according to a Facebook post. 

How do I know if my weight distribution hitch is correct?

The most important thing to check when assessing the performance of your weight distribution hitch is the tongue weight. The tongue weight refers to the amount of pressure that the trailer puts on the ball mount when it is connected. It should be between 10-15% of the total trailer weight for a standard setup.