I had a lot of trouble over the weekend trying to get an accurate measurement of the diameter of the hole on my NH. There's much more stuff in the vicinity of the hole on my NH than there appears to be on your JD. Seems to be about 1-1/2". Don't have the part no. with me but will get it tomorrow. You could always pick up the NH part, and then if you didn't like it or it wouldn't fit, return it.