what should I do if my BMW 3 Series F30/F31 (2012-2019) transmission is slipping

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, transmission fluid pressure gauge, multimeter, fluid catch pan.
• Ensure the vehicle is on a level surface and safely secured with jack stands.
• Disconnect the battery to prevent electrical shorts during repairs.

2. Check and Replace Transmission Fluid

1. Locate the transmission dipstick or fill plug.

   • Remove the dipstick or fill plug to check fluid level and condition.

2. Inspect the fluid.

   • If the fluid is dark, burnt, or has a burnt smell, it needs to be replaced.

3. Drain the old fluid.

   • Place a fluid catch pan under the transmission pan and remove the drain plug or pan bolts.
   • Allow the fluid to fully drain.

4. Replace the filter (if applicable).

   • Remove the transmission pan and replace the filter according to manufacturer specifications.

5. Refill with new transmission fluid.

   • Use the manufacturer-recommended transmission fluid.
   • Reinstall the drain plug or transmission pan, ensuring all bolts are torqued to the specified values (consult service manual for torque specs).

3. Inspect and Repair Internal Components (if necessary)

1. Remove the transmission from the vehicle.

   • Disconnect all necessary components including driveshaft, electrical connectors, and fluid lines.

2. Inspect clutch packs and bands.

   • Check for wear on clutch packs and bands; replace if damaged.

3. Check the torque converter.

   • Inspect for proper operation and any signs of damage or overheating.

4. Reinstall the transmission.

   • Follow the reverse procedure for reinstallation, making sure to connect all components securely.

4. Reconnect Battery and Clear Codes

1. Reconnect the battery.

   • Ensure all connections are secure.

2. Clear any stored error codes.

   • Use the OBD-II scanner to clear any diagnostic trouble codes from the transmission control module.