my BMW 3 Series E90/E91 (2005-2012) won't shift into gear, what should I do?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Tools Required: Jack and jack stands, socket set, OBD-II scanner, fluid catch pan.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Remove the transmission fluid fill plug.
  2. Check the fluid level; if low, add the appropriate transmission fluid (refer to owner's manual for specifications).
  3. If the fluid appears dirty or burnt, drain and replace it.
     • Use a catch pan to collect old fluid.
     • Install a new transmission filter if applicable.
     • Fill with new fluid until it reaches the correct level.

3. Inspect and Replace Clutch Components

• Sub-steps:
  1. Remove the transmission from the vehicle (this may require disconnection of the driveshaft and exhaust).
  2. Inspect the clutch disc, pressure plate, and flywheel for wear.
     • If any components are damaged or worn beyond specifications, replace them.
  3. Replace the clutch master and slave cylinder if leaking or malfunctioning.
  4. Reassemble the transmission and ensure all connections are secure.

4. Adjust Gear Linkage

• Sub-steps:
  1. Inspect the gear linkage for proper alignment and secure mounting.
  2. Adjust the linkage according to manufacturer specifications if misaligned.
  3. Test the shifter for smooth operation after adjustments.