The E46 BMW is a popular platform for enthusiasts, and a manual transmission swap is a common upgrade. This guide provides a detailed walkthrough of the installation process, covering key steps and potential challenges.
Preparing for the Swap
Before beginning the swap, gather all necessary parts, including a manual transmission, clutch kit, flywheel, driveshaft, pedal assembly, shift linkage, and wiring harness. Having a ZHP knob and boot, along with shift pin, 5th gear, and reverse service kits can enhance the driving experience. Reference DIY guides like this one: http://www.bimmerfest.com/forums/showthread.php?t=219285 for detailed part lists and procedures.
Installing the Clutch System
Begin by assembling the clutch master and slave cylinders. Mount the clutch module on the master cylinder, attach the adapter lead and the hose to the brake reservoir. Connect the UUC SS clutch line to the high-pressure line on the slave cylinder. Refer to realOEM diagrams for accurate pedal assembly installation. Remove the driver’s seat for easier access and pull back the carpet before installing the new pedal assembly to access the firewall punchout for the high-pressure line.
Installing the Transmission
Remove the old automatic transmission and flywheel. Install the new pilot bearing into the crankshaft and mount the manual flywheel using new, longer bolts, torquing them to the proper specification. Use a clutch alignment tool to center the clutch disc before installing the pressure plate. Torque the pressure plate bolts in a star pattern. Install the new clutch release bearing onto the transmission input shaft and lubricate the spline. With assistance, carefully maneuver the manual transmission into place, ensuring proper alignment with the starter. Bolt the bell housing to the engine and install the new crossmember brace.
Driveshaft and Reverse Lights
Install the manual transmission driveshaft, starting with the flex disc connection. Use butyl tape or double-sided trim tape on the center support bearing. For reverse lights, wire the reverse light switch on the transmission to the corresponding terminal in the glove box fuse panel.
Wiring and Coding
Wire the clutch safety switch and module according to the wiring diagram, connecting them to the DME and EWS. This will enable the car to start. After the mechanical installation, the vehicle’s software needs to be updated. Obtain the ZCS (GM SA VN) information from a BMW dealer and provide it to a coding specialist to generate a manual transmission SA code. The dealer or an independent shop can then apply this code and reprogram the modules, including the DME, EWS, ASC/DSC, and GKE/ZKE. This step is crucial for eliminating error lights and ensuring proper functionality.
Final Steps
Reinstall the exhaust system with the correct hangers for the manual transmission. Consider upgrading to a short shifter and DSSR for improved shift feel. Finally, thoroughly inspect the entire installation for any loose connections or potential issues.
This comprehensive guide provides a solid foundation for undertaking an E46 Manual Transmission Swap. Remember to consult detailed DIYs and seek professional assistance if needed. Enjoy the rewarding experience of driving your newly converted manual E46!
