4L60 (THM 700-R4)

T.V. Cable System

The T.V. Cable used with the Automatic 700-R4 transmission should not be thought of as an automatic downshift cable. The T.V. cable used on the Automatic 700-R4 controls line pressure, shift points, shift feel, part throttle downshifts and detent downshifts. The function of the cable is similar to the combined functions of the vacuum modulator and the downshift (detent) cable used on the 350C transmission.

Figure 7A-3 Throttle Valve (T.V.) Cable And Linkage:

Figure 7A-4 Throttle Lever And Bracket Assembly:

The T.V. cable operates the throttle lever and the bracket assembly (Figures 7A-3 and 7A-4). The Throttle Lever and Bracket Assembly serves two (2) basic functions:

1. The primary function of this assembly is to transfer the carburetor throttle plate movement to the T.V. plunge in the control valve assembly as related by the T.V. cable and linkage (Figure 7A-3). This causes T.V. pressure and line pressure to increase according to engine throttle opening and also controls part throttle and detent downshifts. The proper adjustment of the T.V. cable is based on the T.V. bushing at engine wide open throttle.

Figure 7A-3 Throttle Valve (T.V.) Cable And Linkage:

Figure 7A-6 Throttle Valve Lifter Rod:

2. The second function of the assembly involves the T.V. exhaust valve lifter rod, spring and the T.V. exhaust ball. The function of this system is to prevent the transmission from operating at low (idle position) pressures, if the T.V. cable should become broken or disconnected. If the cable is not connected or broken, the T.V. lifter rod will not move from its normal spring loaded position which holds the T.V. exhaust check ball off its seat. The T.V. lifter rod will drop down to allow the T.V. exhaust ball to seat only if the cable is broken, disconnected or extremely out of adjustment. With the transmission pan removed, it should be possible to pull down on the T.V. exhaust valve lifter rod and the springs return the rod to its normal position. If the throttle lever and bracket assembly or lifter rod binds or sticks so that the T.V. lifter rod cannot lift the exhaust ball off its seat, high line pressures and delayed upshifts will result. The normal shape of the T.V. lifter rod is shown in Figure 7A-6. The right angle leg must not be bent to any other angle or it will not function properly.