I don't know about yours, but on my 58 CJ5, it was on the passenger side near the motor mount. At least that's what I remember, it's been 6 years since I owned that one, my memory's not as good these days. lol
Jim_Lou is right... Thats where I found mine on my Scrambler after looking all over the jeep for two days. It was a little rusty so get a brillo pad and a hose. It's right on top of the frame rail between the tub and frame. Just enough room for your fingers unless you have a body lift. What year is your jeep????