Audi A6 C5 Automatic Gearbox Oil Change

Changing the oil in an Audi A6 C5 automatic gearbox might seem like a more daunting procedure than changing engine oil or air filters, but it also has a specific service interval. You can perform a partial oil change on the automatic transmission yourself. This guide focuses on the ZF 5HP19 gearbox.

When to change automatic gearbox oil and which oil to use for Audi A6 C5

The accepted service interval for the automatic gearbox is approximately 60,000 km.

The choice of oil for the Audi A6 C5 automatic transmission usually falls on the yellow MOBIL LT71141 ATF. LIQUI MOLY ATF TOPTEC 1200 or SWAG 30914738 are also sometimes used.

For a partial change, you will need about 6 litres of new oil; the exact amount can be determined by the volume of drained fluid — you need to put back in as much as you took out.

In addition, you will need a new sump gasket, a new oil filter (sometimes the old one is just cleaned, but replacement is better), and new plugs (drain and filler). You may also need to replace the sump bolts if the old ones are rusted.

How to change the oil in an Audi A6 C5 automatic gearbox

Place the car on an inspection pit, ramp, or lift to access the oil sump. Place a container under the drain plug and unscrew it using an 8 mm hex bit. After draining the oil (about 5 litres), screw the plug back in with a tightening torque of 40 Nm.

Next, unscrew all the bolts around the perimeter of the sump using a Torx T27 bit. Carefully remove the sump containing the remaining oil and remove the old gasket.

Next, unscrew and remove the old oil filter for replacement or cleaning. It is secured by a pair of screws with a tightening torque of 5 Nm. Install the oil filter. Then install the sump gasket and the cleaned sump itself along with the magnets. The tightening torque for the sump bolts is 10 Nm.

Now you can unscrew the large filler plug using a 17 mm hex socket. A plastic insert installed above the filler hole prevents oil from flowing out. You need to insert a bent tube through the hole in the insert so that the tube goes inside the sump. Then pump in the new oil using a special syringe, fluid pump, etc.

After pumping in sufficient oil, tighten the filler plug along with the sealing ring to a torque of 80 Nm. Check that the plugs and sump are securely tightened, then start the engine and cycle the gearbox through all positions.

When the automatic gearbox sump warms up to approximately 43 degrees Celsius, unscrew the filler plug without switching off the engine. If fine spray comes out of the hole, the oil level is correct; if there is no oil spray, top up the oil with the engine running until it flows back out. Then tighten the filler plug.

Part numbers for ZF 5HP19 Automatic Gearbox on Audi A6 C5

• Automatic gearbox oil sump bolts — VAG WHT000747;
• Original automatic gearbox oil filter with sump gasket — VAG 1V325429, analogues: MAHLE HX84D, MANN H2826KIT, ALCO TR019 and others;
• Drain plug — 01V321377;
• Filler plug — 01V321376;
• Filler plug sealing ring — 01V321379.