4. Attach the New Jack
To keep installation simple and quick, buy the same model tongue jack as the one you are replacing. This way you know it will fit, is sufficiently rated to support the tongue, and won't create clearance issues, which is important with swing jacks. Also, install the tongue jack in the same position as the old jack. (With jacks that attach to a permanent bracket using a C clip, you have no choice.) Securely bolt or clip the jack in place, making sure it will not wobble or collapse once it is supporting the trailer tongue. Some jacks might also require that you install a rotating grip on the crank lever.