Camshaft Gear 3946436 for Cummins 4B3.9 – Scheduled Maintenance Service Part
3946436 Camshaft Gear for Cummins 4B3.9 6B5.9 — CNC-machined tooth profile, heat-treated alloy steel, replacement for timing-critical service intervals. Typical wear shows as timing drift or gear lash noise; plan single-gear or full timing set exchange at overhaul to avoid cascading damage Fits engines across QSB and ISB series used in loaders and forklifts; verify engine serial to confirm variant match Older Cummins generations remain in active supply with consistent aftermarket availability Replacement cycle guidance included with shipment for fleet maintenance alignment.