Cummins ISX 3689630 Timing Gear PAI 172037OEMCROSS REFERENCE: 3689630 3681144 3686914 3680547 APPLICATION: Cummins ISX Multiple Use Application. DETAILS: Genuine Part OEM Number Description Quantity 3681143 TIMING GEAR 1 3680201 IDLER GEAR BUSHING 1 Color Finish Gray Material Steel Tooth Count (outer) 64 BRAND: PAI 172037OEM Cummins 3689630 Timing Gear PAI 172037OEM. Aftermarket truck parts and truck repair parts. Maintains valve timing accuracy and supports consistent engine synchronization.