FYI--my kwikee single step is a 28 series on a '97 dolphin mh. it worked seldom and the motor would get really hot. i looked at this forum and other forums to learn all i could. removed motor and gearbox from mh, took apart. the motor worked ok and the 3 plugs were 'egg shaped'. found that auto zone and kragens have ' window regulator gear plugs' (#74410 - $7.99). got a set and replaced worn plugs in my motor-gearbox. put everything back and steps work like new. just think, several rv parts places could have sold me a new motor-gearbox for $150.+ and i would be in the same place as now, only with less pocket change. i think some of these rv suppliers are out to 'wear our butts out' if a person doesn't do a little investigative work on their own. hope this helps someone else, as previous posts helped me. thanks to all inputs, sawman