CURT 2-5/16" Trailer Hitch Ball 15,000 lb — Chrome, 1-1/4" x 2-5/8" Shank, Heavy‑Duty

CURT 40078 is a heavy‑duty 2-5/16-inch chrome trailer hitch ball rated to tow up to 15,000 pounds with a 1-1/4" x 2-5/8" shank for secure mounting.

This precision‑made tow ball combines hot‑forged high‑strength steel, a corrosion‑resistant chrome finish, and fine‑threaded hardware to deliver stable, long‑lasting towing performance. Designed and tested to meet VESC safety specifications, the 40078 is built to pair with Class 5 hitches and commonly used 2-5/16" couplers on utility, boat, and RV trailers.

Will this hitch ball fit my trailer coupler and ball mount?

The CURT 40078 uses a 2-5/16" diameter ball so it mates directly with any trailer coupler sized for 2-5/16". The shank measures 1-1/4" in diameter and 2-5/8" long, which matches many standard Class 5 ball mounts and drop shanks.

• Ball diameter: 2-5/16" to fit 2-5/16" couplers
• Shank size: 1-1/4" diameter, 2-5/8" length
• Compatible with most Class 5 hitches when mount thickness allows
• Check mount hole diameter and thickness before installation

How strong and durable is the CURT 40078 for heavy towing?

This hitch ball is rated for a gross trailer weight of 15,000 pounds and is manufactured from hot‑forged steel to withstand high towing loads. Chrome plating protects the surface from corrosion, while fine threads and included hardware improve clamping strength under repeated use.

• Rated capacity: 15,000 lb gross trailer weight
• Construction: hot‑forged high‑strength steel
• Finish: chrome plating for rust resistance
• Hardware: zinc‑plated hex nut and helical lock washer included

What are the installation and maintenance considerations?

Installation requires securing the shank through the ball mount and torquing the nut to the specified value for a safe clamp. Routine maintenance includes inspecting the ball surface, threads and hardware for wear or corrosion and reapplying lubricant to prevent galling.

• Required torque: tighten to manufacturer‑specified value (450 lb‑ft referenced for fine‑thread hold)
• Use the supplied zinc nut and lock washer for secure fastening
• Inspect before each tow for wear, rust, or uneven surface
• Keep ball surface clean and lightly lubricated to reduce wear

How does this tow ball meet safety and testing standards?

CURT designs the 40078 to meet U.S. VESC testing standards, ensuring consistent manufacturing and safety margins appropriate for high‑capacity towing. These tests validate material integrity, thread performance, and load capacity to provide confidence on the road.

• Tested to VESC (Vehicle Equipment Safety Commission) specifications
• Quality control focused on material, threads, and plating
• Intended for use with properly rated hitch assemblies and couplers

Who is this for? The CURT 40078 is aimed at drivers who tow heavy loads—truck, SUV, or van owners pulling large utility trailers, boat trailers, fifth‑wheel adapters with appropriate mounts, or heavy RV/camper loads—who need a rugged, well‑tested 2-5/16" hitch ball. Choose this model when you require a high‑capacity, corrosion‑resistant tow ball that matches industry sizing and comes with the hardware needed for a secure installation. Always confirm trailer and hitch ratings and follow vehicle manufacturer guidelines before towing.