^

The brake bands can be adjusted to specific limits, as in the case of Mercedes Benz. This is done to compensate for wear and tear of the bands due to usage, and is being done by a qualified transmission mechanic. I have no idea if this is possible in a Nissan gearbox, you can ask the opinion of a Nissan casa for this. If the gearbox had water intrusion, chances of rusty/stuck/corroded mechanicals are more likely.