Question 1

When gearbox oil needs changing

Accepted Answer

Gearbox oil lubricates the gears, bearings and synchronisers. Manual gearbox oil change intervals are typically 60 000–120 000 km, automatic gearbox 60 000–80 000 km. Even if the manufacturer labels the oil "lifetime", this refers to the car's designed life — not its true service life.

Symptoms of aged gearbox oil: hard shifts on a manual, jerks on an automatic, rising fuel consumption and grinding noises from the gearbox. Metal shavings on the sump magnet signal early gearbox wear. Regular changes are the most cost-effective way to extend gearbox life.

Question 2

How gearbox oil is changed

Accepted Answer

The car is raised on a lift and the drain plug is opened. The old oil is drained into a container and evaluated — dark black oil shouldn't appear and metal shavings shouldn't be present. The drain plug is renewed or fitted with a new sealing washer.

On automatic gearboxes the filter is also renewed during the oil change. Fresh oil is filled through the manufacturer's fill point — on some modern cars this is under the cylinders and requires specialist tools. Correct oil level is measured with the car warm — too little causes wear, too much causes foaming.

Question 3

Why does gearbox oil age?

Accepted Answer

Gearbox oil is exposed to constant heat, wear metal and oxidation. As it ages the viscosity changes, additives deplete and lubrication weakens. Hot conditions — towing or heavy city driving — accelerate ageing significantly. 10 000 km with a trailer consumes oil more than 30 000 km of normal driving. If the oil isn't changed on time, wear metal starts eating into synchronisers and internal clutches.

Gearbox Oil Change in Vantaa