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Tech Sheet: 700R4
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Custom TV linkage guidelines (TV = Throttle Valve). This instruction is intended for use by customers who have purchased a High Impact "BadBoy" 700R4 or AOD transmission. This instruction is intended to assist persons custom-installing one of these transmissions into a vehicle that did not previously have this trans. If you are simply directly replacing a stock trans with the same model of our bad boy, the stock TV cable and settings will work.
It is very important to set up the TV cable correctly in 700R4 and AOD applications. Incorrect TV cable adjustment can cause the transmission to burn up in very short order. It is not brain surgery, but it is necessary that it not be too loose, or transmission damage will result. Following is a discussion of how to go about setting this up:
On the carburetor or throttle body: You will need to fabricate a lever, or modify the existing lever, so that as the throttle is opened, the TV cable gets pulled. You also want to build this lever in such a way that the “ratio” of pull is adjustable. In other words, the length out from the throttle pivot to where the cable is attached. If it is farther out this arm, the cable will be pulled a greater amount when you mash the throttle than if it is closer in.
Make sure that the TV lever on the transmission is at idle when the throttle is at idle, and likewise for full throttle. There is some extra travel built into the transmission’s TV lever to allow for adjustment, so that a small amount of transmission lever travel (but not too much) may be left at full throttle. Be careful that the transmission lever does not bottom-out and prevent the throttle from opening all of the way. Regardless of how you fabricate your TV linkage, you must provide a means of adjusting the TV rod or cable length in addition to providing the correct linkage ratio.
As a general guideline for adjustment, keep in mind that low TV pressures cause soft, early shifts, and can be corrected by lengthening the linkage rod (or tightening the cable) , while high pressures cause harsh, late shifts and can be corrected by shortening the linkage rod (or loosening the cable). If in doubt, err on the high side of normal, because too much TV pressure is always better than too little.
The ideal factory setting for TV pressure in an AOD is such that a TV cable equipped vehicle will have no slack nor any tension in the cable with the throttle fully closed (at curb idle position, engine need not be running).
When setting up the TV ratio and TV cable position in a custom application, There are thus two factors to consider: The ratio, or arm length, of the actuating lever on the throttle, and how tight you set the TV cable. Set so the TV cable is pulled fully when the throttle is wide open. Adjust the arm length (ratio) so that with the TV cable fully pulled at WOT, there is no tension or slack in the TV cable at idle position. Do not run it any looser than this. If the shifts re too early/too light, shorten the arm length and adjust for full pull on TV cable at WOT, and a bit of pull on TV cable at idle. In this way, you can tune the operation.
The TV cable sets the system pressure in the trans. System pressure is raised as the throttle is opened so that there is more pressure holding the clutches and bands, and so they will not slip under the increased torque at wider throttle settings. Too loose of TV cable setting will not apply sufficient apply pressure to the clutches and bands, and they will slip under torque. If they slip, they will burn up in very short order. You want to feel nice, firm, positive shifts at all throttle settings.
Too tight will make rough, jerky, slamming upshifts and downshifts.
