Yokomo YZ-631W1 Spare Main Shaft for Works'91 YZ-W91  [YZ-631W1]

YZ-W91 main shaft: fit and function

The Yokomo YZ-631W1 is a purpose-made replacement main shaft for the Works'91 TeamSpec YZ-W91TS and YZ-W91 1/10 scale touring car chassis. It is supplied as a service part for routine rebuilds or after repairs where drivetrain components are refreshed.

Fitment applies only to the Works'91 models named above, so double-check your chassis code before purchase. The main shaft transmits drive between gearbox elements and, if compromised, can undermine smooth power delivery and cornering precision.

Swap procedures are consistent with other shafts in this chassis series: remove the gearbox and rear bulkhead to access the shaft and bearings, replace components keeping alignment and preload to factory recommendations, then clean and lubricate during reassembly to prevent early wear.

Replacing the shaft is a maintenance action that preserves the original drivetrain geometry, helping to sustain predictable throttle control and handling balance after prolonged use or impact recovery work.