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Ford AOD

BubMullen

Contributor
Jr. Member
Joined
Oct 20, 2025
Messages
60
Just found a Ford AOD transmission on Facebook. I have a 1973 with a 302. Any ideas on if it can replace my current auto transmission
 

widowmaker77

Contributor
Sr. Member
Joined
Oct 11, 2007
Messages
564
You will need the adapter to make the aod bolt to the transfer case. Wildhorses, toms and broncograveyard all sell the adapter. Trans will need to be disassembled to install adapter. Also crossmember will need to be modified and moved back on the frame rails approx 3/4” or either buy a new one from one of the vendors that made for the aod/4r70 trans. Only other thing I can think of is figuring out how to attach the tv cable from the trans. Not sure on what’s available to do that. I run a 4r70w so it doesn’t have the tv cable like the aod does.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,069
If you are asking if it is a direct replacment for the C4 you currently have. No, it is not.
With a fair bit of work, and a good chunk of money, it can be made to fit. Then even more money to make it work right.
The AOD has a very tall .667 overdrive ratio. Almost no chance the current axle gearing will play nicely with that much overdrive.
The AOD in the early years had oiling issues. If it is '87 or prior, expect to find the gearset to be destroyed. It probably still drove, but it is well known for being chewed up. You have to do a full rebuild anyway to install the adapter kit. Considering they went out of production some 30 odd years ago, it will need a rebuild at this point.
It was released in 1980, so a design from the 70s. Not a highlight in auto technology. Some innovative things that were (rightfully) never used in any other automatic transmission, the torque convertor bypass for overdrive.

If the transmission was free, it would still be too expensive. There are (a few) fans of them. The rest of us have found better, newer, more functional options.
And you would need driveshafts reworked as well as the transfer case is moved rearward since it is longer than the C4 you want to replace.
Anyone who spent any time in the 80s and 90s remember these early overdrive transmissions were well known for wearing out real quick if run even slightly hard.
 

widowmaker77

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Sr. Member
Joined
Oct 11, 2007
Messages
564
If
Sounds like a ton of work and money thank you all !
If I were you and was looking for a OD trans ( and this is what I did) I’d skip the aod and go for the 4r70w. Better gearing and stronger trans. All that I mentioned above will still need to be done to fit the 4r BUT you will need a trans controller to shift it. There’s also a few good 5 speed manual transmissions if you’d like to go that route.
 

mdainsd

Contributor
Full Member
Joined
Mar 16, 2025
Messages
263
Loc.
San Diego
You will need the adapter to make the aod bolt to the transfer case. Wildhorses, toms and broncograveyard all sell the adapter. Trans will need to be disassembled to install adapter. Also crossmember will need to be modified and moved back on the frame rails approx 3/4” or either buy a new one from one of the vendors that made for the aod/4r70 trans. Only other thing I can think of is figuring out how to attach the tv cable from the trans. Not sure on what’s available to do that. I run a 4r70w so it doesn’t have the tv cable like the aod does.

I have yet to locate a crossmember, to buy, to facilitate the installation of the 4R70 into my bronco. If you could point me in the right direction?
 

904Bronco

Contributor
Bronco Guru
Joined
Sep 28, 2004
Messages
6,695
Loc.
San Martin, CA
I have yet to locate a crossmember, to buy, to facilitate the installation of the 4R70 into my bronco. If you could point me in the right direction?

Modify the stock crossmember per A/A directions, or Tom's Crossmember. (I have done both) And if in stock, I would lean towards Tom's product.
I did the A/A mods to Clifford, as I had all the stock parts to modify, and I had already made the longer L brackets for the frame. (Crossmember has to move back 1.5" if using the A/A kit for a non 4x4 transmission)

https://tomsoffroad.com/products/66...ransmission-dana-20-transfer-case-crossmember
 

mdainsd

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Joined
Mar 16, 2025
Messages
263
Loc.
San Diego
Yeah, I followed that procedure but its a kludge that doesn't measure up to the rest of the project. Even moving it back, it had to be modified to drop the rear of the transmission 3/8" as it was as the transfer case was hitting the body cross support. Just checked Tom's and there it is! It doesnt say if it works with the A/A adaptor though.
 

SLOWnEASY

Contributor
Sr. Member
Joined
Sep 26, 2022
Messages
517
Loc.
San Diego, Ca.
I always considered adding an overdrive automatic to my Bronco. But the cost of the conversion always stops me in my tracks. I'll take the higher RPM and slightly less gas mileage over the price of all the parts.
 

904Bronco

Contributor
Bronco Guru
Joined
Sep 28, 2004
Messages
6,695
Loc.
San Martin, CA
Yeah, I followed that procedure but its a kludge that doesn't measure up to the rest of the project. Even moving it back, it had to be modified to drop the rear of the transmission 3/8" as it was as the transfer case was hitting the body cross support. Just checked Tom's and there it is! It doesnt say if it works with the A/A adaptor though.
It will work with the AA adapter, but either option I listed above will require you to shave some of the bushing and washers down...
 

mdainsd

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Full Member
Joined
Mar 16, 2025
Messages
263
Loc.
San Diego
That had to be done for the stock crossmember too. The A/A adaptor wont accept full-sized cushions and washers.
 

widowmaker77

Contributor
Sr. Member
Joined
Oct 11, 2007
Messages
564
I have yet to locate a crossmember, to buy, to facilitate the installation of the 4R70 into my bronco. If you could point me in the right direction?
@904Bronco got you the right link for the premade crossmember. I modified my original crossmember. If you can weld a little bit it’s super easy to modify. Here’s a link to a YouTube video a friend of mine did a few years back when he modified his.
 

904Bronco

Contributor
Bronco Guru
Joined
Sep 28, 2004
Messages
6,695
Loc.
San Martin, CA
@904Bronco got you the right link for the premade crossmember. I modified my original crossmember. If you can weld a little bit it’s super easy to modify. Here’s a link to a YouTube video a friend of mine did a few years back when he modified his.
He is right, AA's instructions are weak, their pictures are grainy. You can go to their website and print something cleaner off.

At least by watching this you can get an idea about the mods that need to be done.
 
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