When should you have your automatic gearbox flushed?

For most conventional automatics and CVTs, our workshop advises 60,000 to 80,000 km. That is our own cautious advice, not a factory requirement. What your car maker or the gearbox manufacturer specifies is shown next to it in the table. A conventional automatic is a gearbox with a torque converter, a fluid coupling between the engine and the gearbox. A DSG is a gearbox with two clutches. A CVT is a continuously variable automatic without fixed gears.

Sources: ZF LifeguardFluid 8 product information, auto motor und sport (March 2026, DSG intervals). “Our advice” is the advice of Autobedrijf Willemsbrug and not a factory requirement.

You can read more about each gearbox type on our page about DSG maintenance. It also shows which DSG is fitted to which model. Do you drive a different make? We can look up the interval and the right fluid for that too.

No. Filled for life means the car maker does not include a fixed fluid change in the service schedule. It does not mean the fluid does not age. ZF, the maker of the 6HP and 8HP automatics fitted to many BMWs, among others, writes that its gearboxes are generally filled with lifetime fluid. In the same product information, ZF still advises a fluid change after 150,000 km.

ZF also says when it can be wise to change the fluid sooner: with high temperatures and heavy loads, and when it is not known how the car was used in the past. That last point applies to many used cars. The Dutch edition of TopGear wrote in September 2026 that gearbox manufacturers such as ZF and Aisin advise replacing the fluid, even when the car maker describes the gearbox as sealed for life. What that term means in practice is explained in our article on whether automatic gearbox fluid is really sealed for life.

Have the gearbox flushed sooner if it works harder than average. Heat is the biggest enemy of transmission fluid. The hotter the fluid gets, the faster it loses its ability to lubricate. These are the situations in which we use the lower end of the interval:

Do you not drive much? The fluid still ages, through time and moisture. A car that mainly does short trips can have a gearbox in worse condition than the mileage suggests.

Ageing fluid usually announces itself through small changes in the way the gearbox shifts. If you recognise one or more of these signs, do not wait until the odometer reaches the interval:

These complaints can also come from wear, a sensor or software. Our article on recognising automatic gearbox problems explains what each complaint can mean.

The mechanic looks at the mileage, the service history, the way the gearbox shifts and the condition of the fluid. Only then do we advise a flush, a fluid change or further investigation. This is how it works in our workshop:

1. Looking up the gearbox type: from the registration number we can see which transmission your car has and which fluid it needs.
2. Test drive: the mechanic pays attention to jerks, slipping, the moment of each gear change and how the gearbox behaves when cold and when warm.
3. Reading the fault memory: where possible, we read the transmission control unit for stored faults.
4. Assessing the fluid: colour and smell tell us a lot. Fresh fluid is clear. Dark fluid that smells burnt is old or has overheated.
5. Advice: you hear what we see, what we advise and what it costs. We only flush the gearbox once you have agreed.

If a flush is not yet needed at your mileage, we will tell you that too. You can read how the treatment itself works on our page about automatic gearbox flushing.

If you wait too long, the fluid loses its lubricating and cooling properties and the damage may already be inside the gearbox itself. A flush then comes too late. Fresh fluid helps with complaints caused by old or contaminated fluid. A flush does not repair worn clutch plates, bearings or a faulty mechatronics unit.

According to TopGear (September 2026), repairing an automatic gearbox can easily run into thousands of euros, and even a used automatic gearbox in good condition costs € 1,500. A timely flush is therefore the cheapest way to protect the gearbox. What a flush costs and what the price depends on is explained in our article on the cost of an automatic gearbox flush.

Do you already have complaints? Then with us it starts with a test drive and reading the fault memory. If the gearbox turns out to be worn, a flush makes little sense and you hear which other options there are. You can read more in our article on problems after a gearbox flush.

The gearbox type is rarely shown on the Dutch registration certificate, but a garage can look it up using the registration number. Call us with your registration number on +31 10 479 00 00 and we will see which transmission is fitted and which maintenance goes with it. This is how you can trace the service history yourself:

Would you like to combine the flush with a car service? Then we plan both in one visit. You receive a quote in advance for the agreed work.

No. It is a rule of thumb for most conventional automatics and CVTs. A wet DSG has its own requirement from the manufacturer, and for the dry DQ200 the manufacturer does not specify a fixed oil change. Call us with your registration number and we will look up the requirement for your version.

First check the service book and the previous owner’s invoices. If you find nothing and the car has covered more than 80,000 km, assume it has not been done yet. ZF advises changing the fluid sooner when the history is unknown. We can assess the fluid and take the car for a test drive before you decide.

No. Flushing more often than the interval does not harm a healthy gearbox, but with normal use it adds little. You would be paying for fresh fluid while the old fluid still works well. Stick to the interval and watch for the signs of ageing fluid.

Yes. Transmission fluid also ages through time and through short trips, in which the fluid does not get properly warm and moisture stays behind. So have the fluid assessed from time to time during a service, even if the mileage is low.

Yes. It is sensible if you cannot find out when the fluid was last changed. ZF names an unknown history of use as a reason for a shorter interval. Have a test drive done and the gearbox read first, so you know whether a flush makes sense or whether something else is already going on.

The treatment itself usually takes two to three hours. On top of that come the test drive, reading the fault memory and the final check. So you leave the car with us and we call you as soon as it is ready. You can use a free loan bike, as long as one is available.

Yes. That applies if the hybrid has a conventional automatic or a DSG. Those gearboxes need the same fluid maintenance as in a car without a hybrid system. We change the oil in a DSG and do not put it on the flushing machine. We do not flush an e-CVT, as fitted to many Toyota and Lexus hybrids.

• ZF Aftermarket: ZF LifeguardFluid 8, product information (lifetime fluid and advice to change after 150,000 km)
• auto motor und sport: DSG-Ölwechsel erklärt: Intervalle für DQ200, DQ250, DQ381 (March 2026, in German)
• TopGear Nederland: Automaatolie vervangen: zo voorkom je dure reparaties (September 2026, in Dutch)