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Aod A-Ok?I have an early Mustang with a small-block and a Holley carb, and a couple years ago I decided to replace the stock three-speed auto trans with a later-model AOD overdrive automatic. I had the trans (from an '86 Mustang police car) freshened and then installed it. The overdrive was great, but the shift timing and quality were never what I'd hoped for. After a couple years, the trans began refusing to shift into overdrive. Everything seemed correct, so I pulled it and brought it back to the guy who built it. He re-freshened it and I put it back in, and although it now goes into overdrive, it doesn't shift right at all. I know the TV (throttle-valve) cable adjustment is essential to proper operation, and I recall that last time we adjusted it using a gauge, but this time the trans guy says to just adjust the slack out of it and it should be good. Well, it's not, and I'm afraid to drive the car because I know I could wreck the trans if it's not set up properly. It shifts early and sloppily, and in Overdrive it feels like its slipping, plus it won't kickdown. My TV cable is an aftermarket unit from Lokar, and it's connected to the Holley in one of the lower holes that would be used for a GM kickdown cable. Am I doing something wrong, or does the trans have to come out again?Dave SharpPhoenix, AZ
You're correct about the importance of proper TV adjustment on Ford's AOD trans, and wise for parking the car until you can sort this out. It sounds like your trans wasn't set up correctly even before you had it rebuilt the second time, though it was probably adjusted for too much TV engagement rather than too little, which may be what you are experiencing now.
First of all, your main problem is probably that the place you've connected the TV to the Holley carb is incorrect. The AOD's TV cable has to travel in exact proportion to the throttle cable (1:1 ratio), so the distance from the throttle shaft for the throttle cable should theoretically be the same as that for the TV cable. However, most kickdown-style linkages don't require as much travel as the throttle cable for proper operation, and the kickdown portion of the carb's throttle lever (the lower half) is probably shorter than the top side, where the throttle cable (or rod) hooks up. The result is insufficient travel of the TV cable, which means that you either have too much throttle valve actuation at idle, or too little at WOT.
Step One in correcting this is obviously to set up your TV cable connection so that a 1:1 ratio is achieved between the throttle linkage and the TV linkage. For the Holley carb, this may require you to fabricate an extension for the lower portion of the throttle lever, and again, you're trying to obtain the same distance from the throttle shaft to the TV cable hookup as you have from the throttle shaft to the throttle cable.