Using the Ford AOD with a Holley carburetor

Categories: [Cars]
Tags: [cars], [holley], [carburetor], [aod]

Hooking a Holley carburetor to an AOD transmission isn't too bad, once you figure out the trick to it. As you can see in the picture below, the basics of the linkage are simple. AOD-Carb-linkage-big

The Ford AOD uses a throttle valve (TV) cable instead of a vacuum diaphragm to tell the transmission how much throttle you're giving the motor, so it can time the shifts. Unlike a vacuum modulator, adjustment of the TV cable is critical. A mis-adjusted cable can cause you to fry your transmission in only a few miles.

One common mistake with AOD conversions is getting the ratio between the throttle and the TV cable wrong. It'd be easier to just bolt the TV cable to that lower hole in the throttle bracket, but that won't work properly. As you can see in the pictures (click to enlarge), I've made a small bracket to reposition the TV cable. The cable needs to move exactly as much as the throttle. AOD-Carb-nolinkage-big

The TV cable is a nice piece sourced from Lokar. The carb plate is a Moroso throttle plate with the Morse cable bracket included, and the TV cable bracket was hand-fabricated from steel stock. The carb bracket is made out of galvanized sheet metal, because that's what I had laying around. The two small holes were included in the piece I used, no extra charge.

To set it up, simply follow the instructions in your shop manual or shift kit manual to adjust the line pressure. Also keep in mind, if you ever are driving and notice a super-sloppy shift from 1-2 or 2-3, stop now and check and/or adjust the cable.

If you frequently adjust your idle speed or remove the cable set, you may want to mount a pressure gauge under the hood, so you can quick-check the pressure without burning your hands on the exhaust. I've picked up some parts to do this, but I haven't installed them yet.