For your 2007 Winnebago Sightseer Class A motorhome steps, it is possible to replace just the gearbox if the motor and controller are functioning properly. Your RV likely uses a Kwikee or Lippert step system. We recommend considering these compatible gearbox options:

- Lippert 379160 Gearbox Linkage: Includes gearbox and linkage, compatible with many Kwikee step models, ideal for direct replacement.
- Kwikee 379147 Motor/Gearbox Assembly: Contains motor and gearbox (without control unit or linkage), suitable if your existing parts are intact and you want a cost-effective solution.
- Lippert 676061 Motor Assembly: Replacement motor with screws for 14Nm Imgl RV steps.

Since you lack the exact model number, contacting Lippert customer support for assistance and SKU verification is advised to ensure the correct part. Once you obtain the SKU, Elkhart RV Parts can help you order the precise gearbox needed. This approach will help resolve the issue where your steps extend partially and chatter when retracting.