Converting Your 4WD 4L80E to 2WD: A Comprehensive Guide

If you have a 4WD vehicle with a 4L80E transmission, you may be wondering if it’s possible to convert it to 2WD. The good news is that it is indeed possible to do so.

However, there are a few things you need to keep in mind before you start the conversion process.

Things to Consider Before Converting 4WD 4L80E to 2WD

  • Transmission Output Shaft
    The output shaft of a 4WD 4L80E transmission is longer than that of a 2WD version. Therefore, you’ll need to replace the output shaft or have it shortened to fit the 2WD driveline.

    The output shaft is responsible for transmitting power from the transmission to the driveshaft. You can purchase a 2WD output shaft that is compatible with your transmission or have a professional machine shop shorten your existing output shaft.
  • Driveshaft
    You’ll need a new driveshaft that is compatible with the 2WD transmission. The length of the driveshaft will also need to be adjusted based on the length of the output shaft.

    The driveshaft is responsible for transmitting power from the transmission to the rear differential. A professional machine shop can help you create a custom driveshaft that fits your vehicle’s specifications.
  • Differential
    A 2WD vehicle has a different rear differential than a 4WD vehicle. You’ll need to swap out the rear differential with a 2WD version. The differential is responsible for transferring power from the driveshaft to the wheels.

    You can purchase a 2WD differential that is compatible with your vehicle or have a professional mechanic install one for you.
  • Transfer Case
    You can remove the transfer case altogether since it’s not needed for a 2WD vehicle. However, if you want to keep it, you can replace it with a dummy transfer case or a spacer.

    The transfer case is responsible for distributing power to the front and rear axles in a 4WD vehicle. In a 2WD vehicle, the transfer case is not necessary, but you can choose to keep it for cosmetic reasons or to maintain the appearance of your vehicle.
  • Transmission Crossmember
    The crossmember that supports the transmission may need to be modified or replaced to accommodate the new 2WD transmission.

    The crossmember is responsible for supporting the weight of the transmission and keeping it in place. You may need to modify or replace the crossmember to fit the new 2WD transmission. A professional mechanic can help you determine if the crossmember needs to be modified or replaced.
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How to Convert 4WD 4L80E to 2WD

Now that you know what needs to be done, here are the steps you’ll need to follow to convert your 4WD 4L80E transmission to 2WD:

  1. Drain the Transmission
    Before beginning the conversion, it is important to drain the transmission fluid. The fluid should be drained into a suitable container and disposed of according to local regulations.

    To drain the fluid, remove the transmission pan by removing the bolts and carefully lowering the pan to avoid spilling the fluid. Once the fluid has been drained, the pan can be reinstalled using a new gasket.
  2. Remove Transfer Case
    If you are not keeping the transfer case, it must be removed from the vehicle. Begin by disconnecting the transfer case from the transmission using a socket wrench or torque wrench.

    The bolts that secure the transfer case should be carefully removed, and the transfer case should be supported using a transmission jack or similar device. Once the transfer case is free, it can be lowered and removed from the vehicle.
  3. Replace Output Shaft
    The next step in the conversion process is to replace the output shaft in the 4L80E transmission with a 2WD version or have it shortened by a professional machine shop. To remove the output shaft, begin by removing the extension housing from the transmission.

    This can be done by removing the bolts that secure the housing to the transmission case. Once the housing is removed, the snap ring that secures the output shaft can be carefully removed, and the shaft can be slid out of the transmission.

    To install the 2WD output shaft, the process is reversed. The new output shaft should be carefully inserted into the transmission, and the snap ring should be secured. The extension housing can then be reinstalled, and the bolts should be torqued to the manufacturer’s specifications.

    If you are having the output shaft shortened by a machine shop, it is important to ensure that the new length is appropriate for the vehicle and that the machining is done correctly.
  4. Install New Driveshaft
    With the 2WD output shaft installed, a new driveshaft must be installed that is compatible with the 2WD transmission and adjusted to the proper length. To determine the appropriate length for the driveshaft, you will need to measure the distance between the transmission output shaft and the rear differential input shaft.

    This measurement can be used to determine the length of the driveshaft required.
    To install the new driveshaft, begin by removing the old driveshaft using a socket wrench or torque wrench.

    The new driveshaft should be carefully inserted into place and secured using the appropriate bolts or clamps. Once the driveshaft is installed, it should be checked for proper alignment and clearance.
  5. Swap Rear Differential
    The rear differential must be swapped out for a 2WD version that is compatible with the vehicle. To remove the old differential, begin by supporting the vehicle securely using a jack or lift.

    The bolts that secure the differential to the axle housing should be removed, and the differential can be carefully lowered and removed from the vehicle.

    The new differential can then be installed by reversing the process. The bolts should be torqued to the manufacturer’s specifications, and the differential should be checked for proper alignment and clearance.
  6. Modify Crossmember
    The transmission crossmember may need to be modified or replaced to accommodate the new 2WD transmission. To modify the crossmember, it may be necessary to cut or weld the crossmember to adjust the position or length of the mounting points.

    Alternatively, a new crossmember can be installed that is designed to fit the 2WD transmission.
    Once the crossmember is modified or replaced, it should be installed using the appropriate bolts or clamps. The bolts should be torqued to the manufacturer’s specifications to ensure that the crossmember is securely mounted.
  7. Refill Transmission Fluid
    After completing the conversion process, it is important to refill the transmission with the appropriate fluid. The type of fluid required will depend on the specific vehicle and transmission model, so it is important to consult the owner’s manual or a trusted mechanic for guidance.

    To refill the transmission, locate the fill plug on the transmission case and remove it using a socket wrench or torque wrench. The fluid can then be added using a funnel or other suitable device until it reaches the appropriate level.

    Once the fluid has been added, the fill plug can be reinstalled and tightened to the manufacturer’s specifications.
  8. Test Drive
    After completing the conversion and refilling the transmission fluid, it is important to test drive the vehicle to ensure that everything is working correctly.

    Start the vehicle and allow it to idle for a few minutes to warm up the transmission fluid. Then, engage the transmission and carefully test drive the vehicle, paying attention to any unusual sounds, vibrations, or handling issues.
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