OK here is what I have .. It is a 92 explorer.. V6 Auto A4LD Trans. Every gear works perfect but NO O/D??? When I am driving down the road and let off the gas all most all the way it will go into O/D.. But when I give it any gas at all it goes back into drive????? So I thought it was the kick down cable. I unhooked it and it still did it?? What is it?? Is it internal or external??? Any ideas will help. Thanks

 

3-4 shift is electronically controlled by the EEC-IV computer; kickdown cable has no effect on the 4-3 shift.
That question: "Is it internal or external?" is precisely the first question to ask. Getting the answer is going to require a little effort:
1) As with any automatic tranny issue, check the fluid level.
2) Get a wiring diagram so you can see what you are up against. The 3-4 shift circuit is relatively simple, but you still need to be able to see it. Run EEC-IV self-tests, and resolve any codes that come up, as problems in the EEC system can translate into 3-4 shift problems.
3) Inspect the circuit. Power to the 3-4 solenoid (and TCC solenoid) at the transmission? Continuity between the transmission and the PCM? Continuity through the solenoid? Etc.
4) While measuring voltage drop across the solenoid, run output state test. You should be able to see the voltage switch from 0-12 V as the solenoid changes state.
5) While measuring voltage drop across solenoid, take it for a drive. Watch to see if/when computer "chooses" to shift into 4th gear and see if the transmission follows suit.
If you've passed all these tests, then the fault lies in the mechanics/hydraulics of the transmission.

 

is the kickdown cable a sensor that tells the computer when the accelerator is floored so it can give the best possible performance? My dads jaguar V8 has somethign called "Kickdown" in the manual. it says "Kickdown is activated when the pedal is pressed fully to the floor and extends shift points to allow maximum power from the engine when needed".

 

In the old days kickdown was achieved solely by a lever or cable connected between the throttle and the transmission. If the throttle moved the lever far enough, the transmission kicked down to a lower gear. On many modern cars, there is still a cable, but more and more cars are going strictly electronic. Many cars over the last ten years, fully-electronic, or hybrid with a cable still present, have an electrical switch that is tripped when the accelerator pedal is pushed all the way to the floor. This is known as a kickdown switch. I bet this is what your manual is referring to.

 

And the A4LD is one of these "hybrids". There's a kickdown cable that attaches to the throttle to instigate a 3-2 downshift (and a 2-1 downshift at slow speeds). the 4-3 downshift (and TCC unlock) are controlled by the EEC-IV computer, WOT kickdown being istigated using the TPS (throttle postion) signal.

 

yeah thats what the manual is referring to then. ill tell you what, i put the pedal to the medal on that thing when passing 10 cars in the pass lane, went from 55-110mph in 5 seconds

 

Back to the problem. The early A4LD had a lot of problems with the overdrive section. The planetary gear frame can snap a weld or the OD star washer can get chewed up. Strangely enough, you can often drive 20-30K with these problems and only miss OD. I would consider a pan srop to see what you find. I found 5 needle bearings in mine and it still ran great!