Transmission maintenance work (BMW 3 Series E30)

External inspection of leak sites

Possible leak locations include:

• Connecting the engine block to the gearbox (flywheel/gearbox gasket).
• Oil filler plug/oil drain plug.
• Flange of the cardan shaft on the gearbox.

When searching for a leak, it is recommended to:

• Clean the gearbox housing with a suitable cleaner.
• Check the oil level and top up if necessary.
• Sprinkle talc on potential leak areas.
• Take a test drive. Since the oil liquefies when the gearbox is warm and penetrates through leaks faster, drive at least 30 km on the highway.
• Raise the vehicle and inspect the gearbox with a portable lamp.
• Locate leaks and eliminate them immediately.

Checking the oil level

The gearbox oil is changed only once during the break-in period (mileage 2000 km): the work must be carried out at a service station. As part of the maintenance schedule, it is necessary to perform only an external inspection of the gearbox; if traces of oil are found, its level must be checked. To unscrew the oil filler plug, a key for bolts with internal hexagons of size 19 mm is required.

Raise the car.



Unscrew the oil filler plug (arrow) on the gearbox. It is located on the right or left side of the gearbox, depending on its type. Place a container under the leaking oil.



Insert your finger into the hole. The oil level should reach the bottom edge of the hole.

If necessary, top up with transmission oil of viscosity grade SAE 80, specification MiL-L-2105-A or API GL4. The oil must be approved by BMW (it's written on the package). If such oil is not available, seasonal motor oil SAE 20, 30 or 40 specification AOI-SE or SF can be added. An oiler or hose is required for filling. When adding oil, place a container underneath to collect the leaking oil.

Oil filling volume

Caution: Never fill the oil above the lower edge of the filler hole.

Tighten the filler plug to a tightening torque of 50 Nm.

Checking the cardan shaft joints

The articulated discs are checked as part of the maintenance schedule every 20,000 km.

Raise the car.

Using a portable lamp, check the front and rear hinge disks for wear, damage or deformation.

Check for cracks in the intermediate tracks in the area of the bushings (arrows).



If necessary, replace the hinge disk. In case of deformation, relieve the hinge disk: if the deformation persists after this, also replace the hinge disk.



Lower the car.