The changes are being made to the 75cc and 55cc units. The older one had a 1/4 inch internal socket head drive and the new one has a 10mm drive hex that can’t be accessed externally. You can still use the same part number and it is interchangeable with the new model. If you are making repairs for the first time, it would be best to use the new hold down pin. If you see a black square then is means it is interchangeable.
The output shaft changes in units 55cc,75cc and 100cc. The refinished the surface area of the rear shaft bearing. When changing out the shaft, you will need to use the new design, the older model will no longer be available. Chart will tell when are affected and what the new part numbers for you frame size.
If you need further assistance with this or any Sundstrand Pump and Motor, call us at 662-871-8403 or 800-361-0068
