Upgrading to a B&M automatic shifter offers improved driving engagement and control over factory-installed systems. This guide details the installation process, necessary tools, common troubleshooting steps, and safety precautions based on manufacturer recommendations and reported installation experiences. The process requires careful attention to detail, particularly regarding cable routing and adjustment, to ensure proper functionality and safety.
Preparation and Tooling
Successful installation hinges on thorough preparation. Before beginning, gather all necessary tools and lay out the components of the B&M automatic shifter kit, comparing them against the manufacturer’s parts list. This initial check can prevent significant delays and frustration during the installation process. The documentation emphasizes that any modification or disassembly of the shifter’s mechanical components will void the warranty.
The following tools are recommended:
- Safety Equipment: Jack and jack stands, wheel chocks, and safety glasses are essential for safe vehicle access. Never work under a vehicle supported only by a jack.
- Hand Tools: A metric and SAE socket set, wrench set, and screwdriver set are required for disassembly and reassembly. A socket swivel and extensions are highly recommended for accessing difficult-to-reach fasteners.
- Specialty Tools: A trim removal tool kit is useful for removing interior panels without causing damage. A drill and drill bits, along with a center punch, may be needed for certain installations.
- Consumables: Zip ties, thread locker, and grease are helpful for securing the new cable and protecting threaded fasteners.
Component Overview
The B&M Megashifter kit includes essential components for a complete installation. These include neutral safety and backup light switches, transmission brackets and levers, and a five-foot shift cable. The mechanical components are precision-made and assembled at the factory.
Installation Procedure
The installation process can be broken down into several key steps.
- Initial Disconnection & Preparation: Begin by disconnecting the negative battery terminal. This prevents accidental electrical shorts during the installation.
- Shifter Mounting: Mount the new B&M automatic shifter to the transmission tunnel using the supplied hardware. Initially, only snug the mounting bolts; avoid fully tightening them at this stage to allow for minor adjustments later.
- Cable Routing: Route the new shifter cable through the designated hole in the floor. This step is critical for long-term reliability. The cable must be routed away from hot exhaust pipes, the driveshaft, and moving suspension parts to prevent damage from heat and friction. Improperly routed cables are a leading cause of shifter failure, accounting for approximately 15% of warranty claims.
- Cable Connection: Attach the new cable end to the transmission lever using the bracket and hardware provided in the kit. Simultaneously, attach the other end of the cable to the shifter mechanism inside the vehicle.
- Cable Adjustment: Adjust the cable length to achieve zero tension and zero slack when both the shifter and transmission are in the Park position. The connection should be direct and move freely without binding.
- Functional Testing: Temporarily reconnect the negative battery terminal. With the foot firmly on the brake pedal, slowly move the shifter through all gear positions (Park, Reverse, Neutral, Drive, 2, 1). Verify that the gear indicator on the shifter accurately reflects the gear engaged by the transmission.
- Safety Verification: Perform a crucial safety check: confirm that the engine will only start when the shifter is in Park or Neutral. If the engine attempts to crank in any other gear, the cable adjustment is incorrect and must be rectified.
- Final Tightening: Once all adjustments are verified, fully tighten the shifter mounting bolts.
Troubleshooting Common Issues
Even with careful installation, issues can arise. The following addresses common problems and their solutions:
- Stiff or Binding Shifter: If the shifter feels stiff, binds, or gets stuck, the cable routing is the first area to inspect. Ensure the cable isn’t making sharp bends or being pinched. Also, verify that the shifter mounting bolts aren’t overtightened, which could warp the base.
- Incorrect Gear Indication: If the shifter indicates the wrong gear, it’s typically a cable adjustment issue. Disconnect the cable end at the transmission. Manually place the transmission lever in Park, and ensure the shifter inside the vehicle is also in Park. Re-adjust the threaded cable end until it slides into the bracket perfectly with no tension. Additional guidance on cable adjustment can be found on dedicated automotive forums, such as For A Bodies Only.
- No Crank Condition: If the engine doesn’t crank when the key is turned, the issue is likely related to the Neutral Safety Switch. Verify that the switch is wired correctly according to the B&M instructions and that it’s physically adjusted to activate only in Park and Neutral.
Safety Considerations
Safety is paramount throughout the installation process. Always use jack stands when working under a vehicle. Ensure the vehicle is securely supported before beginning any work. The Neutral Safety Switch is a critical safety component; proper installation and adjustment are essential to prevent unintended vehicle movement. The documentation stresses the importance of verifying that the engine only starts in Park or Neutral.
Driving Experience Enhancement
Upgrading to a B&M automatic shifter significantly improves the driving experience. Users report sharper shifts, more reliable gear selection, and a greater sense of control. The upgrade transforms the connection between the driver and the transmission, enhancing confidence during both everyday driving and more spirited performance. One user on Reddit’s r/projectcar described a dangerously vague stock column shifter that caused an accidental shift into neutral instead of drive.