For many automotive enthusiasts, particularly those with a passion for performance driving, upgrading the shifter in a vehicle can significantly enhance the driving experience. The B&M Sport Shifter is a popular choice for owners of the Chevrolet Corvette C4 with ZF transmissions, offering a more direct and responsive gear shift feel. However, the installation process for the B&M Sport Shifter in this specific model is notably more complex compared to other shifter upgrades. This article provides a detailed, step-by-step guide based on a real-world installation experience shared by a user, focusing on the key procedures, tools required, and critical considerations for a successful installation.
The information presented here is derived from a firsthand account of installing the B&M Sport Shifter in a C4 with a ZF transmission. The user emphasizes the importance of understanding the unique challenges associated with this installation, including the need for precise measurements, careful assembly, and attention to orientation. This guide aims to equip readers with the knowledge and practical insights necessary to undertake this project confidently and safely.
Overview of the B&M Sport Shifter for ZF C4 Transmissions
The B&M Sport Shifter is a high-performance gear shifter designed to offer a shorter throw and a more direct shift feel compared to stock shifters. This makes it an attractive option for drivers seeking a more engaging driving experience, particularly in vehicles like the Chevrolet Corvette C4 with ZF transmissions. The shifter’s design involves a more compact gear engagement mechanism, which can significantly alter the driving dynamics of the vehicle.
However, as noted by the user who shared their installation experience, this particular upgrade is more involved than many other shifter installations. The process requires not only a range of tools but also a clear understanding of the mechanical components involved. The user highlights that while the B&M Sport Shifter is more aggressive in its shift feel compared to other options like the ZFDoc or Hurst models, it is well worth the effort for those who value a precise and responsive shift.
Preparation and Tools Required
Before beginning the installation, it is essential to gather the necessary tools and ensure that the workspace is suitable for the task. The user in the shared experience utilized a variety of tools to complete the installation, many of which are standard for automotive repairs but are particularly critical for this specific project.
The following tools were used during the installation:
- Bench Vise
- Small Flat Blade Screwdriver
- Long Needle Nose Pliers
- Brake Drum Adjuster
- 3/8” Drive 7/16” Socket
- ½” Drive 13mm Socket
- ½” Drive 15mm Socket
- 3/8”-Drive 10mm Socket
- 3/8”-Drive 7mm Socket
- Side Cutters
- Side Post Terminal Wrench
- Cordless 3/8” Drive Impact Driver
- Cordless Drill
- ½” Drive Ratchet
In addition to these tools, the user also noted the importance of a soft jaw machining vise, which was used to hold parts securely during the installation of certain components, such as the spring pin between the shifter bushing and the gear shift rod adapter.
The user prepared for the installation by removing the car’s top and rolling down the windows, which facilitated better access to the undercarriage. A Quickjack lift was also used to keep the car level and provide easier access to the rear components, particularly during the removal of the exhaust system and the mating of the shift rod and shifter.
Disassembling the Factory Shifter
The first step in the installation process involved disassembling the factory shifter to prepare for the installation of the B&M Sport Shifter. This step required careful attention to detail, as the user had to ensure that all components were properly marked and stored to facilitate reassembly later.
To begin, the user moved the shifter gently to the third gear position, where they could hear it disengage. They then wiggled and tugged upward to remove the shifter. During this process, the user noted the presence of shims and nylon bushings at the ends of the factory shifter, which may fall into the boot. While this is not a significant issue, the user emphasized the importance of keeping track of the shims and noting which ones were front and rear. The combined thickness of the shims was approximately 0.037 inches per end, a detail that could be useful later for adjusting the fit of the new shifter.
The user also marked the nylon bushings over the pivot pins to ensure they could be reinstalled in the correct location later. These bushings were labeled F (front) and R (rear) to maintain their orientation.
Next, the user addressed the flange bolt that held the shift rod adapter in place. In their case, the bolt was flared on the non-headed end, making it difficult to remove with a drift alone. To resolve this, the user used a 9/32” drill bit to remove the flared lip, after which the pin could be punched out with a few taps from a hammer and drift. The user also noted the importance of protecting the shift rod adapter, as it would be reused during the installation of the new shifter.
Assembling the B&M Shifter
Once the factory components were removed, the user proceeded to assemble the B&M Sport Shifter according to the instructions provided in the kit. The user emphasized the importance of organizing all parts and laying them out on a clean microfiber towel, which helped prevent parts from rolling away and ensured that all necessary components were accounted for.
The user applied a small amount of lithium grease to the grooves of the lower bushing before installing the four O-rings. They also coated the O-rings with additional grease to ensure smooth operation and prevent binding. The bushing was then inserted into the shifter’s bottom hole and allowed to rest in place temporarily.
One of the more challenging steps involved installing the spring pin between the shifter bushing and the gear shift rod adapter. The user noted that orientation was critical during this step. To assist with this, they had previously marked the lower shift rod with a ring, ensuring that the opening of the ring faced the front of the car. The slot in the threads of the shifter was aligned to face the rear of the car.
The user recommended holding the assembly in a soft jaw vise while pounding the pin in. They started by inserting the pin into the shift rod, then slipped the slot of the shift rod adapter over the lower bushing in the shifter. After lining up the pin, the user used a hammer to drive it in. Initially, the pin was difficult to start, but once it was seated, it went in easily. The user also used a drift to ensure the pin was recessed equally on both sides.
Adjusting and Finalizing the Shifter
After the initial assembly, the user performed several adjustments to ensure the shifter was properly aligned and functioning smoothly. One of the key considerations was the width of the brass pins in the new shifter assembly. The user noted that the B&M Sport Shifter measured 4.467 inches, while the factory unit measured 4.321 inches. This discrepancy meant that the new shifter was slightly wider than the original, which could affect the fit.
To address this, the user adjusted the brass pins by pounding them inward until the overall width matched the factory measurement plus the thickness of the shims. After adjustment, the width was reduced to 4.392 inches, which was close enough to the factory specification. The user also applied grease to the 3/8” pivot axle before inserting it into place.
The swing plate was then installed over the shifter, with the slot in the shifter threads facing the rear of the car and the threads of the swing plate aligned to the driver’s side. The user emphasized the importance of orientation during this step, as incorrect alignment could affect the shifter’s operation.
Once the swing plate was in place, the user secured it using a 5/16” acorn nut on the passenger side and a standard 5/16” nut on the other side. The assembly was tightened to a snug fit without being overly tight, ensuring that the movement remained smooth and free.
Final Installation and Testing
With the shifter fully assembled and adjusted, the user reinstalled it into the vehicle and performed a final check to ensure everything was functioning correctly. The user emphasized the importance of testing the shifter to verify that the gear changes were smooth and that the shifter operated without resistance or binding.
The user also noted that the B&M Sport Shifter provided a significantly different shift feel compared to the stock shifter. While the user described it as being “really short and tight,” they acknowledged that this might not be to everyone’s preference. For those who prefer a slightly less aggressive shift, the ZFDoc model is suggested as a middle ground between the stock shifter and the B&M model.
Conclusion
The installation of the B&M Sport Shifter in a Chevrolet Corvette C4 with a ZF transmission is a complex but rewarding project for automotive enthusiasts. As demonstrated in the shared experience, the process involves a range of mechanical adjustments, careful orientation of components, and precise measurements to ensure a proper fit and function.
While the installation is more involved than many other shifter upgrades, the end result—a crisp, responsive gear shift—justifies the effort for those who prioritize performance and driving engagement. The detailed steps outlined in this guide are based on real-world experience and emphasize the importance of following the manufacturer’s instructions while also being prepared to make adjustments as needed.
For readers considering this upgrade, it is important to approach the task with patience and attention to detail. The use of the correct tools, proper workspace, and a clear understanding of the components involved will go a long way in ensuring a successful installation. Additionally, consulting the Factory Service Manual and the instructions provided with the shifter is strongly recommended for a comprehensive understanding of the process.