do you need one? what happens if you remove it? i have a 3 speed auto on the floor. I have little understanding of its purpose; can someone knowledge me. thank you!
it controles the line pressure in the trans. you need higher line pressure to handle the increase in power when you accelerate. you will burn up the trans if you dont use it.
Haven't had one on my car in like 70,000 miles.. but I just have 200 I6, maybe that's why it hasn't caused a problem...
Took mine off almost immediately after getting the car when I swapped to 4-barrel carb and aluminum intake on stock 302. Then put in 5.0. Got about 20k miles total on it since removal. Trans still works like a charm but leaks all over. I doubt it leaks from the lack of kickdown lever. I have heard arguments both ways (will damage/will not). Figured if I blow mine up, it will give me an excuse to buy a newer and better built tranny. I guess if you are worried, and yours still fits, keep it. My current intake and carb setup will not let it fit no matter how I mess with it.
The whole time mine was out I could not get the automatic drop to low or lower. Always felt sluggish, no kick when I punch it. I did feel the acceleration but not due to drop in gear. Not sure about damaging.
The kick-down valve affects the pressure boost valve, governor valve and modulator valve. If you disconnect it and shift manually it isn't necessary but if you put it in drive and forget about the shifter then you NEED it connected. The common results of disconnecting it is more heat from the converter trying to get the car moving, Slippage (not that you would notice it from the driver's seat) in second and high gear. When I tear a C4 down I can tell when the linkage has been disconnected because the direct clutches are burnt - sometimes they weld from all the slippage - , and the intermediate bands show blueing on the metal from the heat and the friction surface is checked (pieces are missing) and burnt. The forward clutches also show signs of heat from slippage. The owner usually tells me that the transmission ran "great" until it failed. It doesn't give much warning. Those who get away with removing the linkage are the ones who shift manually and tend to drive their C4s hard. (when the C4 is in manual gears (Rev, 1st and 2nd) the pressure is increased to above the level of the "kick-down" valve pressures.)
Shifting manually...many of us have floor mounted shifters that let us put it in 1st, then shift to 2nd when WE want to (as opposed to when the transmission automatically shifts). Paul, I have an adjustable vacuum modulator and have it set so that the car doesn't shift until around 3500 rpm when I am cruising around. That is OK, isn't it? I usually downshift by hand when passing, but the modulator (I guess it is the modulator) causes it to downshift automatically if I gun it hard while in a higher gear. The kickdown rod is removed, but something else is making it downshift almost as if it was still attached. It started to do this when I put in the new modulator. Just wanted to throw that out and make sure I am not doing anything severly damaging to my trans.
put my linkage in, with the new Edelbrock kickdown bracketry . its not a perfect fit, the throttle cable and kinckdown bar are bumping heads, but it works for now.. anyone have any tips on adjusting the engagement of kickdown passing gear?
adjust the screw so that you can still get full wide open throttle with the screw pressed against the throttle arm on the carb.
Scooper, You are getting poor fuel economy and adding extra wear to your transmission. If you haven't already ruined the modulator by turning it far enough to make the C4 shift so late it will probably not last long before it ruptures. You have modulator pressures near the top of the curve and it will over-ride the governor to do "part throttle" down shifts when the vacuum is low. It will cause problems in the long run. The problem is that the modulator pressure doesn't affect the same circuits as the kick down valve, so the late shifts are only because the governor pressure has to overcome the modulator pressure. That leaves the line pressure low under the worst circumstances.
