my BMW X3 F25 (2011-2018) has a loud noise when shifting gears

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, transmission fluid, fluid pump, clean rags, torque wrench.
• Ensure the vehicle is on a level surface and safely secured with jack stands.
• Disconnect the battery to prevent electrical issues during repair.

2. Inspect and Replace Transmission Fluid

1. Remove the transmission pan (if applicable) using a socket set.
   • Safety Warning: Allow the engine to cool before handling the transmission components.
2. Drain the old transmission fluid into a clean container.
3. Inspect the old fluid for metal shavings or burned smell, indicating internal wear.
4. Replace the filter (if applicable) and clean the pan thoroughly.
5. Reinstall the transmission pan and torque to manufacturer specifications.

3. Address Noise Source

1. Inspect the transmission mounts for cracks or deterioration and replace if necessary.
   • Tools Required: Socket set, torque wrench.
2. If the noise persists, check the transmission internals for wear (bearing, gears, etc.).
3. Consult a professional for internal transmission repairs or replacement if required.

4. Reassemble and Fill Transmission

1. Reconnect any components that were removed for inspection.
2. Use a fluid pump to fill the transmission with new fluid as per manufacturer specifications.
3. Ensure the correct type of transmission fluid is used.