Model: City EYear: '89Description of problem (please be as in depth as possible): Wiper arm fell offAny non-standard parts that might be involved with the problem? No.Hmm... seems that the driver's side wiper arm fell off the other day, and it was a bit of a nightmare getting back home during a sudden heavy shower

. Now that I'm going to replace the thing, should I replace the wheel box for the arm? I know that bits fall off Minis, but I wouldn't have thought that a whole wiper arm would make a bid for freedom! Do the teeth on the wheel box get worn out after time, or should I buy that heavy duty wiper arm that Minispares have? The wheel box seems to be expensive for what it is, so I'm hesitant on buying another one, but are these things supposed to wear out over time?
Any advice always appreciated!