Trailer Hitch Ball

Match three sizes

A hitch ball must match three dimensions: the coupler's ball size, the shank diameter and length that pass through the ball mount hole, and the weight rating needed for the trailer. Common ball diameters are 1-7/8 inch, 2 inch and 2-5/16 inch, and the size is normally stamped on the ball top. The coupler also has its size stamped on it. Using a ball that is too small or too large can allow the coupler to come loose, so the match must be exact.

Weight ratings

• Ball rating: this is the maximum gross trailer weight for that ball. Listings include ratings from 7,500 pounds to well above 15,000 pounds.
• Class of the setup: the receiver, ball mount, hitch ball, coupler and tow vehicle each have their own rating, and the system is limited to the lowest of them.
• Tongue weight: usually about 10 to 15 percent of the trailer weight for conventional trailers. Check your vehicle manual.

Shank and thread details

The shank has a diameter, for example 3/4 inch or 1 inch, and a length that has to clear the ball mount's thickness and allow the nut and lock washer to seat fully. The ball mount's hole size must match the shank, and a smaller shank in a larger hole is unsafe. The product description lists the shank hole size. Torque the nut to the specified value, because under-tightening is a common cause of ball failure.

Finishes and special types

• Chrome: smooth and corrosion resistant, popular and easy to keep clean.
• Raw or zinc steel: utilitarian and common on heavy duty balls.
• Switch balls: offer multiple ball sizes in one unit.
• Cushion or rocker designs: include a flexing mount that absorbs shock for certain trailers and drop heights.

Fitment and use

Verify all ratings against your vehicle's owner manual and the trailer's coupler, and confirm fitment for your exact year, make and model. Lubricate the ball lightly or use a coupler-compatible lubricant, check the coupler latch and safety chains before each trip and inspect for wear, such as flat spots or pitting. Replace the ball if it is worn or damaged. Towing and equipment rules vary by state.

Related parts and common mistakes

A hitch ball is one part of a connected towing system, and several nearby parts are worth checking whenever you replace it. Look at the ball mount for cracks, elongated holes or a bent shank, and make sure its drop or rise holds the trailer level. A trailer that tilts nose-up or nose-down handles poorly and can cause sway.

• Do not reuse a worn ball. Flat spots, pitting or a significantly reduced diameter mean the coupler does not fit properly.
• Do not use the wrong lock washer or skip it. Check the thread pitch and washer specification.
• Latch and pin the coupler every time, and attach safety chains in a crossed pattern.
• Connect the wiring and test lights and brakes before each trip.
• Remove the ball mount when not towing, if it blocks clearance or is a hazard in parking areas.