Ford AOD

[55blacktie]

I would like to hear from anyone who has installed an AOD transmission in their Tbird. I would prefer an overdrive but chose the C4 conversion because I don't want to notch/modify the frame to accommodate an AOD. Thanks.

[paul2748]

I friend of mine put an AOD in his 56. he had to grind down the frame a little. I was there when he was grinding. Not a lot, but necessary. I put a C4 in mine, no alterations to frame of body. If your plan on a lot of highway driving, I would suggest the AOD.

[55blacktie]

I have 2.72 rear gears. Calculated 2300 rpm @ 65 mph. That's within 100 rpm of my brother-in-law's 1988 Mustang 5.0/w 3.55 gears and AOD. Of course, I won't be drag racing, but having a wide-ratio gear set/w 2.90 1st vs 2.46 will help to get it moving. It's certainly better than starting out in 2nd with the Fordomatic.

[55blacktie]

Paul, I would appreciate a pm if you retained the original shifter when doing your C4 conversion.

Thanks

[paul2748]

Yes, I retained the original shifter. The only problem was you cannot access low gear because there is not enough "throw" in the Tbird shifter to access it. . I also used the stock rod from the shifter to the trans but if I remember correctly I had to straighten it. I have heard that others got the full range out of the stock shifter but one that I know did had a problem with Park and readjusted the throw deleting the low spot. If your good at engineering, changing the length of either the stock shifter or the trans shifter it may be possible to have everything.

C4's had three kinds of shifter arms at the trans The one pointed down is for a column mounted shift, the one for a floor shifter was pointed up. You need the one pointed up although additional mods probably can be made to use the other. The later ones (i Guess - and which I used (1980))pointed up and down. I also used the stock Bird kickdown lever, but it had to be extended and the end modified to fit the trans kickdown.

Based on some articles I read on C4's, the best ones are 1970 and up (I used a 1980). That said, I have either a 68 or 69 in a street rod which works great with many miles and years on it (one rebuild in 30 years).

I used the Flat-O kit, no problems with it except the starter gear was hitting the ring gear at certain times. One thin washer to space the starter out solved this problem.

Paul, I would appreciate a pm if you retained the original shifter when doing your C4 conversion.

Thanks

[JimCunn]

"It's certainly better than starting out in 2nd with the Fordomatic".

Why not start in first with the Fordomatic?
I usually shifted mine through all three gears.

[Joe Johnston]

A local shop had a customer's 57 with a strong running 312 engine. They installed an AOD and also 4.11:1 rear end gears. The owner wanted more acceleration from a stop light which the 4.11 provided. The AOD maintained about the same engine rpm at highway speeds. He felt it was a "win - win" and worth every penny. Loves it.

Personally, I wouldn't get hung up about your thinking: "an overdrive but chose the C4 conversion because I don't want to notch/modify the frame to accommodate an AOD" but be more concerned to build a modified car to drive the way you want it to. You are making a modification!! If the frame needs a bit of tweaking, it can be restored back to original should someone else want to do so. It's steel. It can be cut and welded! Build the car the way you want it to perform so you can enjoy it.

[19667L]

Mr. Paul7428 and others: I am about to embark on installing an AOD in my 55. I would love to know what area of the frame needs grinding, so I can do that before I first set in the trans.

And in using the early AOD's w/o a computer, are there differences in the cases?? Or are all early AOD's the same case design??

Is Gearstar the supplier of choice for the adapters??

Thnx all.

Tom in VA

[JimCunn]

I'm also interested in details of the AOD conversion. My engine and transmission are out of my 55 now, so it would be the perfect time to pursue this.

What are the desired AOD transmission years?
Can the Fordomatic shifter be retained?

[paul2748]

Can't help on this - you will have a test fit to determine the spot.. You will have to set up a new trans mount. I didn't exactly see what my friend did so cannot comment.

[dgewe]

We did a drive train update to our '57 in 2010 that included a PA Street Smart AOD package. We bolted our AOD to a 462ci FE Stroker then bolted the whole combo into the '57. Except for a minor leak, the PA built AOD has performed flawlessly. I recommend it! The mount on the AOD didn't line up with the holes in the frame. IIRC, the holes needed to be about 1/2" outside and behind the existing holes and I had to make a 3/4" aluminum bar spacer to position the tail shaft properly. The stock shifter with the detents filed down shifts the AOD. The drive shaft had to be a little longer, so we had one made from a short section of a 3" diameter F100 pickup driveshaft. The FE with aluminum heads, intake, water pump and radiator along with the aluminum case AOD weighs about 180lbs less than the Y-block/Ford-O-Matic. (We decided the suspension should be updated somewhat also. We added 2" lowering springs in front, better Bilstein shocks, fat front & rear stabilizer bars, front disc brakes, power rack & pinion steering, 225 60 R15 tires on 7" wide ford steel rims and a 3.50:1 geared limited slip in the 9".) Everything fit inside the stock sheet metal. '57 dog dish hubcaps complete the illusion. We average 10-12MPG city, 14-16MPG highway with the RPM at 2200 at 75mph on the Interstate.

[19667L]

Bill from NY gave me some good scoop on installing an AOD. He only had to remove the upper inner lip of the X frame members, both sides, back to the center vertical rib of each I beam. And create a short trans mount, but that is the easy part.

I will do a CAD diagram soon, will post. And some of the good pics Bill sent me.

Some one sent me pics of a massive cut to each frame member, very unnecessary!!

Tom in VA

[JimCunn]

"Some one sent me pics of a massive cut to each frame member, very unnecessary!!"

That's good news. The large cutout looked scary.

[19667L]

Pics. I might ponder moving the engine 1" forward and minimize the depth of cut. Overkill, likely yes, but that is how I do things sometimes!!

Bill bought his trans adapter from Bendtsen's Transmission Center in Ham Lake MN. Gearstar also makes an adapter. Not sure which is thinner, or better. I will post any info I gather.

Tom in VA

drvr side

psgr side

CAD diag