U27-4CA SWIVEL FRAME Parts group U27-4CA J00001 SWIVEL FRAME J00002 SWIVEL FRAME J00102 ARCH FRAME J10000 SWIVEL BEARING J20002 SEAT SUPPORT [CANOPY] J20004 SEAT SUPPORT [CABIN] J30001 STEP [CANOPY] J30002 STEP [CABIN] sale parts diagram catalog online construction equipment excavator tractor