TH 400 - tv


I have built a TH400 with mech. modulator conv. The tranny has a shift kit, race clutches, sprague, 3200 conv, cooler, etc..... My question is reguarding the TV cable. The throw of the mech. modulator is shorter than that of a 2004R. I have therefore moved the tv cable stud towards the center of the throttle bracket to make it more "sensitive" to match the throw of this modulator i got. Can someone explain exactly what this TV cable does in a 400? I was told it only controls downshifts but then why would a 400 have a separate kickdown solenoid. Will the tv control fluid press??
The cable you described repalces the modulator.

It's function is to give the trans an input to tell it the load on the engine.

Not as critical as a TV cable on a 700R4 or 200-4r but still a critical device.

At WOT it needs to have the cable tight.

You can adjust from this so that light throttle is more or less modulator pressure in the trans.

You have the right idea as far a moving towards the center of the throttle linkage.

You will need to readjust each time though to bring it back to full extension at WOT.

It does not control the kickdown function, you do this by using a throttle mounted switch to apply 12V to the connector on the trans.
This will provide Kickdown.

The more modulator pressure you produce the later and firmer the shifts will be.
But they will max out at around 4000 rpm unless you hook up the kickdown.
Been awhile since I worked on one of those setups, but as I recall it dod work like a TV cable where the more you extended the cable the later the shifts would be.

So less extension would be earlier shifts.

Back it off until it has no tension on the cable, this should be idle, then hook it ot the carb so that at WOT it is at full extention.