Silly coupler question can't find answer anywhere??????

[SATEAR]

How to you measure what size hitch ball you need?

I have a '47 Kitt that I am rebuilding and it is not on the tongue anywhere as to the size of the coupler.

Do you measure the interior width across the coupler or the exterior width across the coupler or is it neither of these measurements?

I bought a 1 7/8 ball and tried that and it seemed to fit without moving around but I want it to be the exact ball that the coupler needs.

Thanks for your Help!

[B52]

Try a 2" ball in the coupler. If it won't fit, use the 1 7/8!!

[laoutdoorsman]

Try a 2" ball in the coupler. If it won't fit, use the 1 7/8!!

X-2

[CPlater]

Measure across the inside of the coupler. Coupler sizes are based on ball diameter.

[Scooter]

might the value of pi might be useful here?

(oops, re-read and saw the ball size is already known...I suck so bad in math the reading part even trips me up)