Been changing the oil in the gearbox of the marmite wagon today or should i say diluting old oil with new as you cant drop the oil out of the torque converter so i have to suck the old oil out the dipstick with a little pump i bought and then measure how much came out and then pump the same amount of new oil back in through the dipstick tube, then take it for a run to mix it all together and keep repeating until it's looking cleaner, just about to have my third run only sucking just over 2L out at a time which is not far off half of whats in there. Once the oil is looking cleaner i have to drop the sump off the gearbox and change the filter then repeat the oil change process again.