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700R4 Transmission - Must Have T.V.

Taking The Guesswork Out Of Overdrives

Photography by Jayson Rege

Before we removed the three-piece stack, we looked into the curved slot and found where the carburetor linkage was protruding slightly into the slotted area (arrow). We marked this protruding section so we could remove it when we had the stack back off to finish drilling the hole we started. The three-piece stack was removed, and we finished drilling the hole through the carburetor linkage. Using a file, we removed the marked material on the carburetor linkage and any burrs caused by filing or drilling so the stack would fit snugly together.

We installed the three-piece stack back onto the carburetor linkage using all three pan-head bolts and installed the cable attachment stud into the slot, positioning it at the bottom-most end of the slot.

The modified carburetor was installed back onto the intake manifold, and the plastic T.V. cable clip was snapped onto the cable attachment stud.

To adjust the T.V. cable we started by attaching a 0-300 p.s.i. gauge to the transmission's hydraulic pump diagnostic port located just above the manual shifter shaft. A 1/8-inch NPT plug needed to be removed to install the 90-degree fitting. The gauge should have a hose long enough to reach the engine compartment. We checked the transmission's fluid to ensure that it was at its proper operating level.

With the engine running, we unlatched the T.V. cable's slider lock (arrow) and pulled the slider towards the front of the engine until the transmission's pump pressure stopped decreasing. This pressure reading was recorded.

Once the pressures were stable and would not decrease any more, we slowly pushed the slider back into its housing until we saw the pressure start to rise again. We then locked the slider back down. This reading should be within 2 p.s.i. of the previous reading. This is the most critical part to these transmissions, so if you have any doubts on setting up this system, redo it until you feel 100 percent comfortable it's correct.

We had now established a correct setup of the throttle valve system. We positioned the T.V. cable attachment stud at the bottom-most position of the adapter's slot. This position will communicate to the transmission in a very aggressive way just off idle.

We can easily change this personality by moving the stud position along the slot. If we raise the stud position in the slot to soften the shifts (moving it up and to the right as viewed from the driver's side of the carburetor), we must correspondingly raise the cable-mounting bracket an equal amount using the spacers provided (arrows). This will maintain the correct relationship between the stud and the cable-approach line. By raising the cable-mounting bracket the same amount as the stud was raised, we will maintain the correct pre-engineered relationship between these two components, which is the cable running parallel to the bottom of the carburetor base.

Each time you adjust this relationship, you will need to reset the cable slider, using the pressure gauge. This will ensure instantaneous pressure response with the new setup. This is critically important. Operating the transmission with low hydraulic pressures can very quickly result in transmission failure.

SOURCES
Bow Tie Overdrives
17359 Darwin Ave., Unit C
Hesperia
CA  92345
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