Hi, can you advise if your 1998 leveling jack system is an HWH 310 series manufactured system? I found a help link for a 1998 Thor Regency coach that has a link to a manual for its jack system. Assuming many coaches of a certain era may use similar technology it might work for you. Open the help item and scroll down to the "click here" which will link you to the manual pdf for that jack system. If that does not work for you try actually using the Answer help service (I can't vouch for them) and they may be able to locate the correct manual for you. Not sure if it will cost anything though? Good luck.