How to Build a Stock Car Automatic Transmission

Introduction

Automatic transmissions are a common sight in stock cars, and for good reason. They offer a number of advantages over manual transmissions, including:

• Easier to drive, especially for inexperienced drivers
• Faster acceleration and smoother shifting
• Improved fuel economy

If you’re planning on building a stock car, you’ll need to decide whether to use a manual or automatic transmission. If you choose to go with an automatic, here’s a step-by-step guide on how to build one:

Step 1: Gather the necessary parts

The first step is to gather all of the necessary parts. You’ll need the following:

• Transmission case
• Transmission internals (gears, shafts, etc.)
• Torque converter
• Transmission cooler
• Transmission fluid

You can find all of these parts online or at your local auto parts store.

Step 2: Clean the transmission case

Once you have all of the parts, the next step is to clean the transmission case. This will help to prevent any dirt or debris from getting into the transmission and causing problems.

To clean the transmission case, use a degreaser and a scrub brush. Be sure to rinse the case thoroughly with water afterwards.

Step 3: Assemble the transmission internals

Now it’s time to assemble the transmission internals. This is a complex process, so it’s important to follow the instructions carefully. If you’re not comfortable doing this yourself, you can take the transmission to a qualified mechanic.

To assemble the transmission internals, you’ll need to install the gears, shafts, and other components. Be sure to use the correct torque specifications when tightening the bolts.

Step 4: Install the torque converter

The torque converter is a critical component of the automatic transmission. It’s responsible for transferring power from the engine to the transmission.

To install the torque converter, you’ll need to first remove the transmission bellhousing. Then, you can insert the torque converter into the transmission case. Be sure to align the torque converter with the transmission input shaft.

Step 5: Install the transmission cooler

The transmission cooler is responsible for cooling the transmission fluid. This is important to prevent the transmission from overheating and failing.

To install the transmission cooler, you’ll need to mount it to the frame of the car. Then, you can connect the transmission cooler lines to the transmission.

Step 6: Add transmission fluid

The final step is to add transmission fluid to the transmission. Be sure to use the correct type of transmission fluid for your car.

To add transmission fluid, you’ll need to use a funnel to pour the fluid into the transmission dipstick tube. Be sure to fill the transmission to the correct level.

Conclusion

Building a stock car automatic transmission is a complex process, but it’s definitely possible to do it yourself if you have the right tools and knowledge. By following the steps in this guide, you can build a transmission that will help you win races.