How to change the oil on an automatic ZF transmission

Mechanic measuring the oil level of an engine at an auto shopAll of ZF’s automatic transmissions, such as the AS Tronic series, have their own range of recommended oils which are specifically designed for use at high operating temperatures. ZF recommends that you change this transmission oil once every 80,000 to 120,000km (depending on general conditions and driving style), or at the very least, once every eight years.

Oil acts as a lubricant for your  transmission components, helping to reduce unnecessary  wear. Failure to change the oil frequently enough can result in sub-optimal transmission performance and, in extreme cases, damage to the machine.

  1. Draining the oil

Find a relatively flat container which will comfortably fit your old oil, then place it below your drain plug on the underside of the vehicle.

If the oil smells burnt, or contains large chips then call us straight away. Loose chips or fragments could be an indication of a defective transmission.

Once all the oil is drained you should disassemble the oil pan by removing all of the screws in the correct order.

  1. Replace the oil filter

If your oil pan is metal then you only need to replace the oil filter and sealing ring. You can do this yourself if you have the ZF stipulated tightening torque; if not then we will be happy to do it for you.

  1. Assembling the oil pan

Once you’ve replaced the filter and given the inside a good clean, you’ll be ready to assemble the oil pan again. It’s important to tighten the screws in the right order to make sure the pan doesn’t bend.

When the oil pan is back on you should replace the seal around the drain screw and re-fit it to the oil pan.

  1. Refill

Open the fill plug and insert the right oil for your transmission (for more information see our guide to ZF transmission oils) until it runs out of fill.

Now start the engine and top up the stipulated ZF-oil again until it runs out of fill. Close the plug and switch off the engine.

  1. Test

Turn the engine on and allow it to warm-up. Do this first at first at idling speed, then cycle through the gears staying on each one for between three and ten seconds (for some transmissions you will only need to do three, some four and others all of the gears). When warm, engage the parking lock.

Then check the transmission oil temperature. If it is below 30 degrees Celsius then repeat the warm up routine. If it is above 35 degrees then allow the engine to cool slightly.

  1. Check fill level

When the oil temperature is between 30 and 35 degrees Celsius, open the fill plug. If no oil runs out of the opening then top up with the right oil until it begins to overflow.

Wait until the transmission oil temperature exceeds 40 degrees and a few droplets run out of the fill opening until closing the fill plug.

Once the fill plug is closed you can switch off the engine to complete the oil change procedure.

To make sure these instructions are correct for your transmission, call a member of the technical team on: 01204 701 812.