Bearing Set, Main (.020", set of 3). PART NO: A-MB125-20. Includes 1-206961-20 & 2-206964-20. . MODELS: Allis-Chalmers POWER UNIT: B15 Allis-Chalmers POWER UNIT: IB Allis-Chalmers TRACTOR: B Allis-Chalmers TRACTOR: C Allis-Chalmers TRACTOR: CA Gleaner COMBINE: 60H.