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AOD Transmision


What AOD trans will work with a 1978 2.3 ?

I know that the bell housing was one of the main concerns with Pintos due to spacing. Mine is not an Overdrive version, but it has the C4 transmission. I would hazard a guess that those AOD in Ford Rangers and Mustangs would be a possibility…but ask any transmission shop or website to ensure the fitting…maybe with a bell house adapter. The good news is that they don’t require complicated electronics as they are primarily mechanical in nature.

Here’s an article that was printed in Hemmings that might be of interest to you:
Ford AOD Overdrive Transmission

Happy Motoring!

The article did not mention the AOD used with any 4 cylinder engines. He might read this as it talks about an AOD with a 2.3  Also, not that it is relevant to a 2.3 swap but the article stated that the AOD would fit all 289, 302 .... . But there were some 5 bolt 289 blocks (I have one of them in my Tiger) and the AOD would not fit. So, don't take everything they say as gospel even though I do feel most of the article was accurate.

Another concern would be the current rear ratio the car now has. Do you know what ratios you have? The Hemmings article mentioned with a 3.73 rear you get the equivalent of a 2.50.  I'd think that the .67 overdrive would really alter common Pinto rear ratios (3.55 highest some down as low as 2.70's) that would only work with a steep down hill grade and a strong tail wind.  There are calculators on the internet that can approximate the RPM with given tire sizes, rear and final drive transmission ratios.

 Torque is the force that moves a car. RPM associated with the ratios determines the speed. If the engine isn't operating in the RPM range with the best torque it will always be struggling. Lowering RPM does not always save on fuel. My daily driver Mazda turns 2,900 RPM @ 65 MPH (with an overdrive 5 speed) and still gets about 34 MPG.

UPDATE: I did some calculating (see image). Based on a 185-70-13 tire (23.2 diameter) the lowest Pinto gears (2.73), an AOD overdrive (0.67) and a 65 MPH speed you get 1,722 RPM. For reference the Pinto with a non-overdrive transmission (1 to 1) would be turning 2,570 RPM. That is a full 848 RPM difference!

 So, here is a test (do at your own risk). Get your Pinto into high gear (third on a C-4) and slow it down until you are turning 1,722 RPM. You can do this right by slightly dragging the brake on with your foot on the gas. Now, once the RPM is reached let off the brake and accelerate until you reach 65 MPH but avoid having the car down shift into passing gear. Then know that any acceleration (even the slightest incline) with an AOD in overdrive will be roughly a third slower than that.

I have sort of been there, done that. I have a '64 Studebaker Daytona with a Chevy 350 out of an '85 Corvette. Because mileage was such a factor back in '85 the engine has a torque curve more like that of a truck than a sports car. I put in a 700R4, have 3.07 rear gears and 225-60-16 tires. 65 MPH is about 1,600 RPM. If the road is level and no headwind it is tolerable - barely. The overdrive 4th gear can not be used on regular streets. 45 MPH is about 1,200 RPM and barely above idle. I did the whole swap for about $125 but in practicality the gains were small overall. And to think some guys buy a new 700R4 and pay someone to do the swap (about $5,000 total).

To use an actual Ford AOD as found in the (V8) Fox3 Mustangs, you would need a 2.3 to 5.0 bellhousing adapter plate to start and quite a bit more I'd expect.


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