Gearbox oil change

Q Having read your views on sealed-for-life systems, I wonder if you can help with my 56-reg Volkswagen Touareg V6 3.0 auto? I would like to change the gearbox oil, but I have read it is not very easy as the level plug is also the fill plug. Also, do you have any idea what oil should be used? Roy Sulley

A As you say, the level plug (located at the base of the sump) is also the filler and requires a tube with a small hook to fill/top-up the gearbox. The drain plug is much smaller and can be found at the other side of the sump to the level/filler bung. I would advise that, after draining the gearbox, the sump should be removed and cleaned, along with the oil strainer in the base of the gearbox.

There are four magnets on the gearbox sump and these should be cleaned off before refitting the sump with a new gasket. The sump bolts should be tightened to 8Nm and the drain plug to 20Nm. The sump must then be refilled by removing the filler bung and placing a tube into the sump and hooking it over the side of the filler tube. The capacity of the gearbox is about nine litres, but this will vary according to how much fluid is left in the cooler and torque convertor.

After the initial fill, the engine should be started with the filler bung fitted loosely. Run through the gears with the vehicle stationary. With the engine running (taking care of moving parts and the hot exhaust), remove the level plug. Initially a small amount of fluid may escape from the filler tube. Now fill up the gearbox until the oil is level with the top of the filler tube. This process must be repeated after the vehicle has been given a short run to ensure there is no air in the system.