I have a 69 mustang with an AOD retrofitted into it. It has a 302 with an edelbrock 1406 carb.
I have installed a lokar tv cable,I then trailered the car to a local Transmission shop. They cant figure out how to get the tv preasure right. Is there something that I'm missing? Possibly another
arm on the Edelbrock throttle shaft?
The guy tells me that he can get the preasure too 2lbs at idle but the preasure climbs to fast at
gentle acceleration. Any help is appreciated!!! Thanks Tod
If the pressure comes up too fast, he has to effectively shorten the amount of throw that the throttle arm provides. Essentially, just move the cable end closer to the pivot point. However, this is not the problem. Perhaps your engine is out of tune. When an engine is out of tune, you need to open the throttle further to acheive the same power output. Opening the throttle further to get "normal acceleration" sends a bad signal to the trans through the TV cable---telling it to shift later. Make sure your engine is in proper tune before making any serious changes to the throttle arm on the carb.
What also needs to be done is remove the throttle valve preload spring. This spring is inside the transmission on the TV shaft cam. The spring has a hook on one end wraps around the shaft then has a strait portion. REMOVE THIS SPRING!
There is also a "corrected" throttle arm bracket made by Sonnax. I have never found the need for it with an Edelbrock carb. The location of the lower hole on the throttle arm is right.
When you get everything working right, another thing you will find that happens with the Lokar cable is the lever on the outside of the trans bottoms out on the little cable housing extention. What needs to be done to rectify this problem is to turn that 90 degree bracket around 180. This effectivly moves the cable housing further away from the lever.
The reason for removing the spring is because the Lokar cable is a soft cable. It does not provide any push to overcome the preload spring. The preload spring works with the stock set up because Ford used either a rod or a stiff cable which would develope push.
Good that your engine is in tune. I have seen it too many times where poor engine performance would be the root cause of trans shift timing concerns.
this thread started me worrying. I haven't installed the 90 Mustang AOD I did up yet into my 79 Ranchero and you had me worried. I'm using a stock Mustang TV cable and will have to do the math for the carb arm length for my current 2bbl carb. Next year it will get the EFI 5.0 HO, and the stock Mustang cable is spring loaded between it's tranny bracket and the TV arm so it's always pushed back against it's zero psi stop.
Well my tranmission shop guys gave up! I loaded the mustang back up and brought it home.
I have decided to fix it my self. I have adjusted the tv cable to 0 at idle, the presure rises right off idle to about 42 psi with mild acceleration. the aod wont shift unless I let off the throttle. I think the presure is to high.Do I let more shack in the cable? I think Im almost there. Thanks Tod
The throttle arm is moving too quickly in relation to the accelerator pedal.
That means the arm at the transmission is too short and must be lengthened.
Do not lower the pressure any more or you will be looking for a chocolate bar, namely , crispy critter.
Start from square one.
Raise the car and support it with proper jack stands.
Disconnect the throttle linkage at the transmission.
Install a pressure gauge.
start the engine.
Now slowly move the throttle arm and watch the gauge.
See how far you have to move the arm to get to the 42#'s you spoke of.
Now reconnect the arm and try it with the accelerator pedal.
See how much difference there is.
I bet you will need to add to the overall length of the arm.
Hi Stuart, I guess that just installing the geometry corrector from sonnax corrects the geometry,I have done this. What should I set the presures too?I have an edelbrock 1406 carb with geometry corrector with a lokar kickdown cable. all on a 302 with a 290 duration cam.
You wouldnt know of a person in the St Louis Mo. Area that has done this ? Thanks Tod