my BMW 3 Series makes a shuddering noise when accelerating what's wrong

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Raise the vehicle on jack stands for easy access to the undercarriage.

2. Inspect and Replace Engine/Transmission Mounts

• Sub-steps:
  • Remove any components obstructing access to the engine or transmission mounts.
  • Visually inspect the mounts for cracks or excessive wear.
  • If damaged, remove the bolts securing the mounts and replace them with new mounts.
  • Torque the new mounts to the manufacturer's specifications (usually around 30-50 ft-lbs).

3. Check Driveshaft and CV Joints

• Sub-steps:
  • Inspect the driveshaft for any dents, bends, or signs of wear.
  • Examine the CV joints for cracks or tears in the rubber boots.
  • If any issues are found, remove the driveshaft by unbolting it from the differential and transmission.
  • Replace any damaged parts and reassemble, ensuring proper torque specifications are followed (typically around 15-25 ft-lbs).

4. Transmission Fluid Inspection and Replacement

• Sub-steps:
  • Locate the transmission pan and drain the fluid into a suitable container.
  • Remove the transmission filter and replace it with a new one.
  • Refill the transmission with the recommended fluid type (usually ATF, check owner's manual for specifics).
  • Start the engine and check for leaks around the pan and filter.