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The Plymouth Road Runner is a classic muscle car that many enthusiasts cherish for its performance and style. One of the most effective upgrades for enhancing acceleration is the installation of a 3.73 rear gear. This modification can significantly improve the car’s responsiveness and overall driving experience. In this article, we will explore the benefits of this upgrade and provide a step-by-step guide to installing the new rear gear.
Understanding Rear Gear Ratios
Rear gear ratios determine how many times the driveshaft turns for each rotation of the rear wheels. A lower numerical ratio, such as 3.73, allows for quicker acceleration at the expense of top speed and fuel efficiency. This makes it an ideal choice for performance-oriented driving.
Benefits of Upgrading to a 3.73 Rear Gear
- Improved Acceleration: The 3.73 gear ratio allows for faster acceleration, making your Road Runner more responsive.
- Better Torque Management: This upgrade helps in better managing torque, enhancing the car’s performance during acceleration.
- Enhanced Driving Experience: A more engaging driving experience with quicker throttle response.
- Cost-Effective Upgrade: At around $450, this upgrade offers significant performance improvements for a reasonable investment.
Tools and Materials Needed
- Socket set
- Wrench set
- Torque wrench
- Jack and jack stands
- 3.73 ring and pinion gear set
- Gear oil
- Gear marking compound
- Sealant
Step-by-Step Installation Guide
Step 1: Preparation
Before starting the installation, ensure that you have all the necessary tools and materials ready. Park the Plymouth Road Runner on a flat surface and engage the parking brake. Use a jack to lift the rear of the vehicle and secure it with jack stands.
Step 2: Remove the Differential Cover
Using a socket set, remove the bolts securing the differential cover. Carefully pry the cover off to avoid damaging the gasket. Allow the old gear oil to drain completely into a suitable container.
Step 3: Remove the Old Ring and Pinion Gear
Once the oil has drained, remove the old ring gear by unbolting it from the differential. Next, remove the pinion gear by loosening its retaining nut and pulling it out of the housing. Take note of the shim placement for reassembly.
Step 4: Install the New 3.73 Ring and Pinion Gear
Begin by installing the new pinion gear, ensuring that you replicate the shim placement from the old gear. Tighten the retaining nut to the manufacturer’s specifications. Next, attach the new ring gear to the differential, ensuring it is properly aligned.
Step 5: Set the Gear Backlash
Using a dial indicator, measure the gear backlash according to the manufacturer’s specifications. Adjust the shims as necessary to achieve the correct backlash. This step is crucial for ensuring optimal performance and longevity of the gears.
Step 6: Reassemble the Differential
Once the gear backlash is set, apply sealant to the differential cover and reattach it using the original bolts. Ensure that everything is tightened to the proper torque settings.
Step 7: Fill with Gear Oil
Fill the differential with the appropriate gear oil until it reaches the recommended level. Check for leaks around the cover and ensure everything is sealed properly.
Step 8: Test Drive
After completing the installation, lower the vehicle and take it for a test drive. Pay attention to the acceleration and listen for any unusual noises. This is a great time to assess the performance improvements from your new 3.73 rear gear.
Conclusion
Upgrading to a 3.73 rear gear in your Plymouth Road Runner is a fantastic way to enhance acceleration and overall driving enjoyment. With the right tools and a bit of patience, this installation can be completed effectively. Enjoy the improved performance and the thrill of driving your classic muscle car!