I will assume you have (or had) a Winegard antenna. They are the most commonly used on RV's. The lift mechanism is pretty much the same for all models but they have different antenna heads so that is what you may want to check out. If you want an exact replacement you will need to find out what model it is. If you do a Google search there is all kinds of information on installation, parts, operation manuals etc. Go to the Winegard web to identify what you have.
2014 Palomino Puma 25RS
2011 F-150 Super Crew XLT
Days camped in 2014 - 23
Camped 2015 - 47
Camped 2016 - 51 done - 6 more planned so far