C4 to AOD swap

[marine165]

I've been considering swapping my 3 speed C4 for a 4-speed AOD for the overdrive and lockup torque converter. I've recently come into a decent used AOD, so now I'm getting dangerous.
Has anyone else thought to do this? I know that the AOD is only .25" longer overall than the C4, but I don't know anything about the transmission mount placement. Does anyone know off the top of their heads whether or not there are multiple holes in the frame for the transmission cross member, in order to fit the C4, the FMX, and the C6? I'm curious.
Any little bit would be appreciated!

Mike

 

[bigbrownbird]

Mike,
I did this with my Dad's 79 bird. It is too simple! Dad's 79 had an FMX and 302, so go off those measurements. First off, find a AOD flywheel with the correct balance (the 79 302 has a 28 oz. balance and factory AOD flexplates are 50 oz. I found mine off Ebay, B&M has them as well). The Thunderbird Mount worked with the tranny and no crossmember had to be moved. Plumb new tranny lines, build a bracket for the shifter cable (if you're using the colulm shift, my bracket took me a piece of scrap of angle iron and about 5 minuites to build.) Finally, take the AOD tanny Yoke with your stock driveshaft, take it to a driveshaft shop and have them find a u-joint with two caps of the AOD size and two of the driveshaft size. You don't need to shorten or lengthen the driveshaft, it is too easy. However, don't do like I did, and drive the car without the VERY CRUTIAL TV rod, without it, you'll toast the tranny in no time flat. Best of luck, hope I helped, and let me know how it goes.

Lee

 

[Gearworks]

lee you are correct.

Putting the TV cable on the carb will be a challenge. you'll either have to make a custom bracket or get the setup from an 84 mustang. they were the only AOD equipped carb'd car ford had.

it is CRUCIAL that the TV cable be set dead nuts on, otherwise its like lee said. smoke and crunch.

++or you could always put a manual valve body in it and forget the whole thing :angel

paul

 

[bigbrownbird]

Paul and his maual valvebodies....
i guess to each his own, but if you're going to go with that, might as well go with a stick (hehehe)

Lee

 

[marine165]

::Scratches his head::

Okay, please forgive my ignorance; does this TV rod serve the same function as the vacuum valve on the C4? I've heard that where on the C4 you could drive it around with the kickdown linkage disconnected because the vacuum valve would make the tranny kick down under load, the AOD doesn't, and the kickdown cable serves both functions. Is this the case? Is this the TV rod you speak of? If that is the case, than no biggie; I've already had experience modifying the C4's kickdown linkage to fit on an Edelbrock 4 barrel... this couldn't be too much harder...right? More detailed explaination, please!



Mike

 

[Gearworks]

yes. more or less it does serve the same purpose. TV stands for throttle valve its ford pre-computer comtrol way of the trans knowing where the throttle is so it knows what gear to go into.

its "doable" but i dont have the patience!

paul

 

[bigbrownbird]

Mike,
Althought the TV rod looks similar and is in the same location as a kickdown linkage, It doesn't perform the same function. I'm not exactly sure on what it controls, I'm still learning too, but I do know that it is very important to have. What I do know is that it is like a kickdown cable with an adjustable end by the carburator (or throttle body). It needs to be adjusted to a certain tension. Either way, YOU NEED THIS. I speak from experience. My dad wanted to drive his car, we took it out for a spin and cooked the tranny on the first 3 mile run, and dad got mad and shoved as c6 in.

Lee

 

[Gearworks]

mike,

lee's right. that wonderful rod will not do the trick. the only thing its on there for is to kick a 3 speed out of drive when passing. whereas the tv cable is constantly moving, as it is connected to the throttle actively. it tells the trans where the throttle is. the setting for it is available in any of the haynes manulas for the tbirds or cougars so equipped.

paul

 

[marine165]

Gotcha... I sort of thought it was a cable, actually. And of course it is important because it controls both the kickdown (not that important) and the line pressure (very important!) in the transmission. In retrospect, I think I might like the way the C4 did it with a seperate vacuum valve for the line pressure and a kick down linkage better. But I'll bet the TV cable gives better controlability.
I'm sure I'll be able to modify up a method of connecting the TV cable to the throttle. It'll just take a little banjo work, and I'm no stranger to that!

BTW, Paul, did you get my email from the other day?

Mike

 

[Gearworks]

why yes i believe i did! :driving

 

[marine165]

First off, find a AOD flywheel with the correct balance (the 79 302 has a 28 oz. balance and factory AOD flexplates are 50 oz. I found mine off Ebay, B&M has them as well).

Soooooooo... okay. Bear with me while I work through my sudden attack of stupid.

What you're saying is that my 351W has the 28.8 oz. balance currently on it, and I need to get a replacement flywheel with the 50 oz. balance in order for the transmission to work without shaking itself apart. Is that right?

Just making double sure before I go and do something dumb.

Mike

 

[bigbrownbird]

No mike, if you put a 50 oz. flywheel on, you'll shake your engine apart!
You need to find a 28 oz flexplate iwith the correct dimentions of a AOD flexplate. AOD flexplates have a different dish to them or something, but i am sure that it is diffent. You can't run a factory 50oz AOD flexplate because then your engine will be out of balance. There wasn't any made from the factory (at least to my knowledge) so yuo need to go aftermarket. I got mine, brand new off ebay for 45 bucks. Shop around, I know they're out there.
Best of luck, I hope we're all driving t-birds soon, :driving because it seems like there's a bunch of cars down for the winter, mine included!

Lee