YZ-4 Hardened Main Shaft - Z4-644 by Yokomo  [Z4-644]

Durable replacement for YZ-4 drivetrain

This replacement main shaft is designed specifically for the YZ-4 4WD buggy platform and serves as the central rotating member of the drivetrain. Straightness and material toughness directly affect drivetrain efficiency and long-term wear.

Forged from hardened steel, this item is intended to replace the stock shaft without modification. It keeps gearbox output and wheel hubs in line, resists bending under impact, and secures couplings and bearings reliably.

Fitment tips: examine bearing surfaces and hub fit before assembly, confirm the shaft seats correctly and rotates freely, and change any worn bearing or circlip items to avoid uneven wear. Test rotation with the chassis raised to identify any runout prior to use.