take the belts off and soak 'em in WD-40 overnite. first try by-running the car with the lowest turn motor your speedo can handle (gear accordingly to prevent heat failure). hey, while the car is apart you may as well sevice or replace ALL the bearings.
find a clean flat area and wring the car out for 5 minutes. if things are still tight then re-adjust belt tension by resetting the square "cams" that support the diff & bearings.