Fuller 4303621 Countershaft PAI 900052CROSS REFERENCE: 4303619 4303621 3088 4303619 3088 4303621 APPLICATION: Fuller Transmission Eaton Drive Train Multiple Use Application RT RTO RTLO11610 14610 14710 15610 16710 RTF1110 RTO 16910B AS2 BRAND: PAI 900052 Fuller 4303621 Countershaft PAI 900052. USA truck parts and replacement truck parts. Maintains gear timing and supports consistent torque transfer. All components are proudly manufactured in the U. S. A. by PAI Industries Inc., an ISO9001