I found a set of instructions through our forum here and he didn't ever mention draining the L/U before dropping it to replace the impeller. My repair manual says to drain it but I just replaced the lube in the L/U and ran it only one time in the water, because it seemed like the motor was cooling OK. I am sure it was fine we didn't have any trouble. It probably needs to have a new impeller though. What do you think?