The gearbox attached to the Volvo TMD22 normally is put in REVERSE when sailing. This locks the shaft from turning.
If sailed with the transmission in NEUTRAL, the shaft MIGHT spin, depending on the propeller used, but this will not hurt the transmission. If you have a shaft alternator fitted, this is how it would be used.
The boat should never be sailed with the transmission in FORWARD. If the shaft spins, (and this depends on the details of the fitted propeller) it will damage the clutches inside the transmission.
This applies to the HBW250 transmission, also known as the ZF25M.
The ZF25 hydraulic transmission is a very different beast. I believe all those on Amels were fitted with shaft brakes.
---In amelyachtowners@..., <agav8ter@...> wrote :
When sailing did you have the transmission in gear? Our Amel ser.# 266 never had any turns while sailing and the transmission in gear.