OEM replacement spring arms for the Equal-i-zer Integrated 4-Point Sway Control® weight distribution hitch — 1,000 lb tongue weight model. Sold as a pair. Compatible with 1,000 lb / 10,000 lb Equal-i-zer systems only. Confirm 1-3/8" socket hole before ordering.
The spring arms are the working heart of the Equal-i-zer weight distribution system — they're the components that link the hitch head to the trailer's sway control brackets, transferring tongue weight back to the tow vehicle's front axle and generating the four points of friction that make the Equal-i-zer's Integrated Sway Control® work. If your spring arms are bent, cracked, worn, or have lost tension, the whole system's weight distribution and sway control performance degrades.
The 90-01-1099 is the OEM replacement pair for the 1,000 lb tongue weight (10,000 lb GTW) model of the Equal-i-zer hitch. These are genuine Equal-i-zer replacement parts, built from the same American steel as the original arms with the same geometry and notching required to seat correctly in the 1,000 lb hitch head and engage the sway control brackets properly. They restore the hitch to full rated performance without needing to replace the entire hitch assembly.
Genuine Equal-i-zer replacement spring arms for the 1,000 lb / 10,000 lb system — restores full weight distribution and sway control performance
Includes both spring arms — replace the full set together to maintain balanced performance across both sides of the hitch
Built from the same 100% American-made steel used in new Equal-i-zer hitches — manufactured by Progress Mfg. in the USA
Backed by Equal-i-zer's limited lifetime warranty for the original purchaser — the same coverage as the full hitch system
This is the single most important thing to confirm before ordering: Equal-i-zer spring arms are not interchangeable between different weight rating models. The 90-01-1099 arms fit only the 1,000 lb tongue weight (10,000 lb GTW) hitch head. Installing the wrong weight-rated arms will not work and could compromise safety. How to confirm which arms you need — measure the socket hole: • 1" socket hole → 90-01-0499 (400/500 lb TW models) • 1-1/4" socket hole → 90-01-0699 (600/700 lb TW models) • 1-3/8" socket hole → 90-01-1099 (This Product) — 1,000 lb TW model • 1-1/2" socket hole → 90-01-1699 (1,200/1,400/1,600 lb TW models) Measure the inside diameter of the socket hole in your hitch head where the spring arm inserts. That measurement determines the correct replacement arms — not the sticker, not a guess, not the part number from a neighbor's Equal-i-zer. Also important: If you are converting your system to a different tongue weight rating, you must replace both the spring arms AND the hitch head simultaneously. You cannot simply swap arms to change the weight rating.
Before Installing: • Confirm 1-3/8" socket hole in your hitch head — this is the definitive compatibility check • Park on flat, level ground with the tow vehicle and trailer in line • Use the tongue jack to take all tension off the existing spring arms before removal Replacement Steps: 1. Release Tension: Use the tongue jack to lift the trailer tongue, taking all tension off the spring arms. Do not attempt to remove spring arms while under load 2. Remove L-Pins: Pull the L-pins securing the spring arms in the hitch head sockets 3. Remove Old Arms: Lift the spring arms off the sway control brackets and slide them free from the hitch head sockets 4. Insert New Arms: Slide the new 90-01-1099 spring arms into the hitch head sockets with notched ends inside and labels facing outward. Pin in place with the socket pins and clips 5. Re-Setup: Re-tension and re-setup the hitch per the Equal-i-zer owner's manual setup procedure — re-measure front wheel well height and adjust bracket positions as needed Refer to the Equal-i-zer Owner's Manual for complete setup, tensioning, and adjustment instructions. Contact Equal-i-zer at 1-800-478-5578 with installation questions.
In The Package: • (2) Replacement Spring Arms — Equal-i-zer 1,000 lb TW Model NOT Included: • Hitch head, shank, sway control brackets, or hardware • Socket pins and clips (use existing or order separately if worn) If Converting to a Different Weight Rating: • Must also replace the hitch head — see 90-02-1000 (1,000 lb head) — arms alone are insufficient for a capacity change
Equal-i-zer / Progress Mfg.: Phone: (800) 478-5578 Website: equalizerhitch.com Made in the USA Equal-i-zer is a brand of Progress Mfg. Inc., the same company behind the Fastway towing product line. The Equal-i-zer hitch has received the Trailer Life Magazine Readers' Choice Gold Award nine years in a row.
Measure the inside diameter of the socket hole in your hitch head. That measurement determines the correct replacement arms.
Socket hole measurement is the definitive compatibility check. Contact Equal-i-zer at (800) 478-5578 if you are unsure which arms are correct for your specific system.