Ford Automatic Overdrive Transmission Installation - Automatically Overdrive - Tech
Here Are Some Tips For Choosing And Using A Ford Automatic Overdrive Transmission In Vintage Mustangs
TV Cable Adjustment
The AOD's TV (throttle valve) cable adjustment isn't much different in function than kick-down linkage adjustment on old C4s. Where the C4 differs is its two means of upshift/downshift modulation-vacuum modulator and the kick-down linkage. The AOD has a single TV cable controlled by the accelerator pedal position. Where it gets tricky is the finite nature of the TV cable adjustment. Get it wrong and you risk burning up the transmission. Even though the transmission might be shifting smoothly, this doesn't mean the TV cable is properly adjusted.
First, if you want to do this by the book, you're going to need a 0-100 psi pressure gauge to screw into the TV pressure tap on the right-hand side of the transmission. It is the middle plug in a trio of plugs near the tailshaft housing. You will need a long hose to get the gauge where you can read it. The engine should be at operating temperature at idle.
If you have a carbureted or CFI (Central Fuel Injection) vehicle, Ford says to obtain a TV control pressure gauge block (#D84P-70332-A) or fabricate a block-dimensions are .390-.404-inch thick (for carbureted and CFI engines only). You can also use a 7/16-inch bolt shank as a gauge. The engine throttle position solenoid needs to be disconnected and at rest. The gauge block or 7/16-inch bolt shank should fit perfectly between the carburetor throttle lever and TV control pressure gauge block and TV lever adjusting screw. Adjust the screw for a perfect fit. Transmission control pressure should be 28-38 psi. Optimum pressure is 33 psi. Turning the TV pressure adjusting screw should raise control pressure 1.5 psi per turn clockwise.
If you have an SEFI 5.0L or 5.8L engine, the TV cable adjustment is located at the throttle body with a non-adjustable end at the transmission. First, unlock the TV cable adjustment tab. Have someone hold the accelerator pedal to the floor. Make sure the throttle is at its idle stop position. With the accelerator to the floor, lock the TV cable adjustment tab, which locks in the adjustment. Mark the TV cable adjustment at the notches with a file or knife. This is your AOD's maximum TV cable location. Unlock the adjustment tab and slide the adjustment toward the exposed cable 5/16-inch. Lock the adjustment tab. Make a new mark, which is the minimum TV cable location. Scribe another mark midway between the maximum and minimum TV cable marks. Move the adjustment to the center and take a test drive.
Rule of thumb with a couple of transmission shops we've consulted is to have someone hold the accelerator pedal to the floor with the TV cable adjustment tab unlocked. Then connect the TV cable to the throttle and lock the adjustment tab. Begin your test drive program. Adjust the TV cable one notch at a time until you achieve 28-38 psi control pressure (ideally 33 psi).
If you don't have a pressure gauge, observe when upshift and downshift points occur. Upshifts should be firm and right on time. Overdrive should arrive at 40 mph under mild acceleration. If upshifts occur too soon, the TV cable needs to be adjusted tighter by one notch, then test drive again. If upshifts are too late, you have too much TV cable tension, so back off one notch at a time.