Replace or adjust the kickdown cable connecting the carburetor throttle linkage to the automatic transmission valve body to restore proper downshift function.

Warnings

Tools required

Parts

• Kickdown cable assembly × 1 — BorgWarner or Lokar universal throttle valve cable for TorqueFlite 727/904
• Throttle linkage cable clips × 2 — Use OEM specification
• Transmission pan gasket (if removal required) × 1 — Use OEM specification

Fluids

• Automatic transmission fluid (Type A, Suffix A or Dexron) — 2 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Disconnect negative battery cable to prevent accidental starter engagement
4. Allow engine to cool completely if recently operated
5. Raise front of vehicle and support securely on jack stands
6. Remove air cleaner assembly for carburetor access

Procedure

1. 1

   Disconnect cable at carburetor
   Locate the kickdown cable connection point at the carburetor throttle linkage on the AMC 390 V8. Remove the retaining clip securing the cable end to the throttle arm using needle-nose pliers. Disconnect the cable from the throttle linkage bracket. Note the exact routing and mounting position for reinstallation.
2. 2

   Trace and disconnect cable at firewall
   Follow the kickdown cable from the carburetor to the firewall pass-through. Remove any retaining clips or brackets securing the cable along the engine compartment routing path. Disconnect the cable at the firewall grommet, noting the orientation and seal condition.
3. 3

   Access transmission valve body area
   From underneath the vehicle, locate the kickdown cable entry point on the driver's side of the transmission case near the valve body. Clean the area around the cable connection point with a wire brush to remove debris and corrosion. Apply penetrating oil to the connection hardware if corroded.
4. 4

   Disconnect cable at transmission
   Remove the retaining bolt or clip securing the kickdown cable housing to the transmission case. Carefully pull the inner cable to disconnect it from the throttle valve lever inside the transmission. Some fluid seepage is normal at this connection point.
5. 5

   Remove old cable assembly
   Carefully extract the entire kickdown cable assembly from the vehicle, pulling it through the firewall grommet and removing all mounting clips along its routing path. Inspect the old cable for wear, fraying, or kinking to confirm replacement necessity.
6. 6

   Prepare new cable for installation
   Compare the new kickdown cable to the old assembly to verify correct length and end fittings. If using an adjustable aftermarket cable, pre-set it to approximately the same length as the original. Lubricate the inner cable with light machine oil to ensure smooth operation.
7. 7

   Install cable at transmission
   From underneath the vehicle, route the transmission end of the new cable to the valve body connection point. Connect the inner cable to the throttle valve lever, ensuring it seats properly in the lever slot. Secure the cable housing to the transmission case with the retaining bolt or clip, ensuring a snug fit to prevent fluid leakage.
8. 8

   Route cable through firewall
   Feed the cable through the firewall grommet from underneath, ensuring the grommet seats properly to prevent water and debris entry into the cabin. Secure any intermediate mounting clips along the factory routing path on the engine side of the firewall.
9. 9

   Connect cable at carburetor
   Route the cable to the carburetor throttle linkage following the original path. Attach the cable end to the throttle arm and secure with the retaining clip. Install the cable housing in the throttle bracket, ensuring it is properly seated and will not interfere with throttle movement.
10. 10

    Adjust cable tension
    With the throttle at idle position, adjust the kickdown cable so there is slight slack (approximately 1/16 inch free play) when the throttle is closed. As the throttle is opened to wide-open throttle, the cable should pull the transmission throttle valve fully without binding. Lock the adjustment mechanism per cable manufacturer specifications.
11. 11

    Verify throttle operation
    Manually operate the throttle linkage from idle to wide-open throttle several times, observing the kickdown cable movement. Ensure the cable moves smoothly without binding, kinking, or interference with other engine components. Verify the cable returns to rest position when throttle is released.

Reassembly

1. Reinstall air cleaner assembly ensuring no interference with kickdown cable routing
2. Lower vehicle from jack stands and remove wheel chocks
3. Reconnect negative battery cable
4. Check transmission fluid level and top off as needed with correct Type A or Dexron fluid

Verification

• Start engine and verify smooth idle with no cable binding or unusual tension
• With engine at operating temperature and parking brake engaged, test kickdown function by quickly depressing accelerator pedal; transmission should downshift promptly
• Road test vehicle through all gear ranges, verifying proper shift points and responsive kickdown when accelerator is floored at cruising speed
• Inspect cable routing after test drive to ensure no contact with hot exhaust components or moving parts
• Recheck cable adjustment if shifts are delayed or harsh, or if kickdown does not occur

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