If the s/h tranny has broken an axle it's a sure bet the tranny hasn't had an easy life.....when money is tight & a major componet goes in one of my mowers or tractors I try to buy a cheap running/salvageable mower (or tractor ) to get me through & even better if you can buy the same model as you have for spares interchangeability.........works out cheaper in the long run & if worse comes to worse you can always part it out to recover some money.......whereas you buy a s/h major componet & its a dud there goes $$$'s.....