why does my BMW X3 F25 (2011-2018) transmission slip when accelerating

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat, level surface and engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Transmission Fluid

1. Drain the Old Fluid

   • Place a drain pan under the transmission.
   • Remove the drain plug (if equipped) and allow the fluid to completely drain.
   • Reinstall the drain plug and torque to manufacturer specifications.

2. Remove the Transmission Pan

   • Remove the transmission pan bolts using a socket set.
   • Carefully detach the pan, allowing any residual fluid to drain into the pan.

3. Replace the Filter

   • Remove the old transmission filter by unscrewing or unclip it from the transmission.
   • Install the new transmission filter, ensuring it is seated properly.

4. Clean the Pan and Magnet

   • Clean the transmission pan thoroughly, removing any debris or sludge.
   • Check the magnet inside the pan for metal shavings and clean it as well.

5. Install the Transmission Pan

   • Apply a new gasket to the pan or use RTV sealant as specified.
   • Reattach the transmission pan, tightening the bolts to the specified torque.

3. Refill Transmission Fluid

• Using a funnel, refill the transmission with the correct type of fluid as specified in the owner’s manual.
• Start the engine and allow it to warm up, then check fluid levels again, adding as necessary to reach the proper level.

4. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the vehicle and conduct a road test, paying attention to the transmission's performance and shifting behavior.