Does anyone know how to adjust the tension on the drive chain that goes from the hydraulic motor to the turntable? Managed to snap the chain and have a new chain to put on - but its too tight to get it on and adding a half link makes the chain too slack. The old chain is about a quarter link stretched so it looks if i'm going to have to repair the stretched chain to get it back on again. Ideally i'd like to have slackened it off, fitted a new chain then tensioned it again - but i cant see any way of doing this. Any help gratefully received.