At gearbox number FD 55620 and KC 23959, the position of the reverse light switch relative to the selector rail centerline was raised to reduce machining on the reverse rail.
Interchangeability of the top cover as an assembly is not affected, but the reverse selector shaft as a component is not interchangeable owing to a change in the shaft depth for the reverse light plunger.
The latest selector shaft can be fitted to early covers using additional washers under the reverse light switch.
The early type selector shaft in a later cover will not operate the switch.
PART NUMBERS AFFECTED
516080—————————————————Top Cover Assembly
134290—————————————————Selector Shaft- Reverse
518606—————————————————Top Cover Assembly
154944—————————————————Selector Shaft- Reverse
516099—————————————————Top Cover Assembly
147775—————————————————Top Cover Sub-assembly
518605—————————————————Top Cover Assembly
154953—————————————————Top Cover Sub-assembly
154945—————————————————Selector Shaft- Reverse