We have a nice example of a Subaru Type R in the workshop which has just been taken out of dry storage after twelve years. Most of the work required is routine service items and we quickly had the vehicle up and running
The one unusual fault was that we couldn’t select reverse gear all forward gears were available . After lubricating the external linkage there was no improvement and no amount of force on the linkage would make a difference . After consulting the owner we removed the gearbox and started a systematic strip down to try and locate the fault. .After removing the gearbox end case we inspected the internal selector rods and could see no reason why we couldn’t engage reverse .
Next we removed the center electronic differential and split the gearbox casing . Once we removed the main shaft and lay-shaft we could finally see the reverse gear idler , with this layout the idler is slide along a shaft via short cam actuated by the main selector rod and quite simply the idler gear had seized onto the shaft and the short cam couldn’t move it
Once freed off we rebuild’t the gearbox and then we could select all gears. Not our normal work in fact i haven’t stripped a gearbox since i was an apprentice working along side a very experienced transmission expert tackling many gearbox issues , Hillman Imp transaxles and later Datsun 240Z rear axle showing my age now this was back in 1970’s working in a main dealer .