FMX swop for AOD

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Mister 4x4

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I am happy to see there are a few other AOD fans that also realize that higher Throttle Valve pressure over the factory spec (30-35 PSI) is not harmful, whereas inadequate pressure will lead to incurring damage to the AOD. I set our AOD up with 39 PSI, as it increases the road speed at which the 1-2 and 2-3 upshifts occur. Our setting is just a bit higher than the factory spec, but I was not willing to go much higher as too much of a good thing might become obnoxious or troublesome in having a tranny that shifts a bit more harshly than what I want. Increasing the speeds a little but for the upshift points is one thing, but having upshifts that are so harsh that they will knock the teeth out of my head is quite another.

For anyone wanting to see how to properly set the Throttle Valve pressure at the carburetor for an AOD equipped car I have two YouTube videos Lynda and I created and posted on YouTube. The 2nd video shows a bit more detail than the first video:


When I added a little tension to the TV cable on mine, the shift points were all messed up - I wouldn't even hit 35mph before it dumped into OD under normal driving - spirited take-offs shifted even quicker (telling me it was way too high). Then I found a post on one of the other Mustang forums with a line worker talking about how they installed the TV cable at the factory, which once I followed that advice (reset back to where it was when I got it, basically), everything was fine and the shift points were back to normal.

If you prefer the quicker shifts, then yeah a little bit of tension on the cable (i.e., higher pressures) won't hurt anything. It's having the slack that's bad because of low fluid pressure. Those are great videos, and certainly could offer some peace of mind knowing that it definitely won't burn up due to low pressures, but IMHO they tend to over-complicate things - several hundred thousand AODs set-up from the factory by simply ensuring there's no tension/no slack in the cable tells me everything I need to know.
 

1973grandeklar

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@1973grandeklar, I have detailed above the neutral safety/switch.
The thing is, the travel distance of the lever on the trans is shorter on most AOD's, so you can do as I did, move the pivot point higher on the shifter arm. There is then match on the dial inside, and no need to modify anything on the harness.
Or if you want, you can use the all in one safety switch/reverse plug on the trans and hook it to your harness.

Another option, is to modify the transmission lever so it has the exact same length as the previously installed trans and shifter/electrics will work as well. But as I've found out, the levers are extremely hard. They have a heat treatment that makes basic modification really tough. I have spend hours modifying the TV lever just to have it aligned to the cable to not get any chances of cable wear and oh boy did that thing fought hard!! The shifter arm isn't hardened, so it was easy pizy.

Yes, the FMX is the grand mother of the AOD. They indeed share the same Ravignaux planetary.
The AOD can take punishment for sure but has 2 flaws in its design ( that can be easily fixed ).
- The first is the snap ring used on the first clutch after the pump, its the reverse on top of my head, but it turns depending on gears you're in, and centrifugal forces can force that ring to open and it then release the "sandwich" of that clutch.
I've used a Sonnax incapsulated snap ring (2 pieces vs one) replacement for that. I have somewhere the ref number if you need it.
(top left on pict).

- the inner shaft, is thin, and on "hard" downshift it moves back and forth and can on pre 89 AOD's with cast drums (90-93 have light weight iron drums), slam the shaft into the clutch splines. At some point if it comes a bit too deep, it will close an oil passage.
So here you have 2 options. You can fix as I did, let machined a small groove, add a ring that prevents the play, and additionally create extra oil passages on the drum (top right on pict).
Or like some do, replace the shaft by a stronger one, which in my opinion is BS as this doesn't address the faulty design and would also mean change the drum too.
That is in case of a lock converter. If you plan non lock, then if your converter has high stall, then yes, you need a stronger shaft as de converter multiplication applies loads of torque on that thin shaft, You'd still should had that ring to the new shaft. On non lock cases, always add a trans cooler no matter what.

View attachment 59609

The flex plate can be reused only if 28oz.

All the mods above are all present in all the AOD's you'll find in speed shops. TCI Streetfighters, monster trans etc..
But if you plan a non lock converter and the trans is in its juice. If your right foot is heavy, you may have problems at some point...
Thank you. Just wanted to address any weakness and you helped tremendously. I think I have a plan for my 351C-4V, now I think I have a transmission to put behind it!
 
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My understanding is that the AOD has the similar gear train design as the FMX. It is a Ravigneaux planetary gearset. So the transmission should be highly compatible as an upgrade? I understand the cases are different, the lock up thing is AOD, and the TV cable use. But what else is different between the FMX and AOD. The FMX was listed for light duty, is the AOD beefed up?
I ask because my 73 Grande has a C6 and will be getting a Q code 351C (using the 72 Mach 1 engine) with a Sniper system on top. But I have the flex plate from a 302 with an FMX. Flex plate is like new. I have an AOD from an 85 F-150 laying around as well (no flex plate). Seems this might be a good path forward instead of rebuilding a C6, rebuild the AOD and install? I will be using a Holley TBI so adding TV cable should be straight forward.
Also I seen mention of the neutral safety and reverse switch? Cannot use the 1973 OEM switch from C6? Splice into the OEM switch on the AOD?
The AOD neutral safety/backup lamp switch it totally different. I ordered a pigtail connector for an AOD, and spliced in the wires from our original C4 neutral safety/backup lamp/ignition interlock switch wiring. Here is a YouTube video showing how I did that for our 1973 Mach 1 AOD transplant project last year:



Following is the s\description from that YouTube video, which includes where I got our pigtail, and the part #:

For our 1973 Mustang C4 to AOD swap project I needed to get the original vehicle wiring to work with the AOD Neutral Safety/Backup Lamp Switch. The AOD came with its own Neutral/Backup Switch installed, but the old C4/FMX/C6 Neutral/Backup Switch connector does not plug into the AOD switch directly.

I ordered an AOD Neutral/Backup Switch pigtail from Summit Racing.I then spliced the AOD pigtail wires into the old C4 Neutral/Backup Switch wiring harness. The resulting pigtail with the C4 harness end can now be plugged into the Mustang wiring harness.

The part # for the AOD pigtail from Summit Racing is RFW-PG057:

 
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When I added a little tension to the TV cable on mine, the shift points were all messed up - I wouldn't even hit 35mph before it dumped into OD under normal driving - spirited take-offs shifted even quicker (telling me it was way too high). Then I found a post on one of the other Mustang forums with a line worker talking about how they installed the TV cable at the factory, which once I followed that advice (reset back to where it was when I got it, basically), everything was fine and the shift points were back to normal.

If you prefer the quicker shifts, then yeah a little bit of tension on the cable (i.e., higher pressures) won't hurt anything. It's having the slack that's bad because of low fluid pressure. Those are great videos, and certainly could offer some peace of mind knowing that it definitely won't burn up due to low pressures, but IMHO they tend to over-complicate things - several hundred thousand AODs set-up from the factory by simply ensuring there's no tension/no slack in the cable tells me everything I need to know.
I still did the formal setup for our Throttle Valve cable adjustment, using an oil pressure gauge and all. I also intentionally set our TV a little higher than spec to increase out shift points, which worked out nicely. The TV being set using initial cable tension feel looks like it ought to work fine. But, being in unfamiliar waters I opted to use the oil pressure gauge. No regrets, but I would never knock your approach.

 

Mister 4x4

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I still did the formal setup for our Throttle Valve cable adjustment, using an oil pressure gauge and all. I also intentionally set our TV a little higher than spec to increase out shift points, which worked out nicely. The TV being set using initial cable tension feel looks like it ought to work fine. But, being in unfamiliar waters I opted to use the oil pressure gauge. No regrets, but I would never knock your approach.

Not knocking yours, either. At the end of the day, making it work properly and/or what works best for your style of driving and preferences is all that matters.

Something I forgot I had pics of: adapting the factory NSS/Reverse Lights harness to the AOD harness. The leftover wire is for the light inside the shifter indicator - I routed mine differently, since I have an AOD shifter rather than the one that came with the car.

Factory harness piece coming in from the bottom/left, AOD harness on the top/right
AODharness1.jpg

AODharness2.jpg

AODharness3.jpg

This is the AOD pin-out I used, and referenced the Yellow Body Electrical manual for the factory pin-outs.
AODswitch.gif

Hope this helps.
 
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Not knocking yours, either. At the end of the day, making it work properly and/or what works best for your style of driving and preferences is all that matters.

Something I forgot I had pics of: adapting the factory NSS/Reverse Lights harness to the AOD harness. The leftover wire is for the light inside the shifter indicator - I routed mine differently, since I have an AOD shifter rather than the one that came with the car.

Factory harness piece coming in from the bottom/left, AOD harness on the top/right
View attachment 59684

View attachment 59685

View attachment 59686

This is the AOD pin-out I used, and referenced the Yellow Body Electrical manual for the factory pin-outs.
View attachment 59687

Hope this helps.
Thank you for the AOD NS/BL connector pinout. I did not have that, and it may prove useful. I am going to add it to my pinout conversion PDF file.
Not knocking yours, either. At the end of the day, making it work properly and/or what works best for your style of driving and preferences is all that matters.

Something I forgot I had pics of: adapting the factory NSS/Reverse Lights harness to the AOD harness. The leftover wire is for the light inside the shifter indicator - I routed mine differently, since I have an AOD shifter rather than the one that came with the car.

Factory harness piece coming in from the bottom/left, AOD harness on the top/right
View attachment 59684

View attachment 59685

View attachment 59686

This is the AOD pin-out I used, and referenced the Yellow Body Electrical manual for the factory pin-outs.
View attachment 59687

Hope this helps.
Nicely done. Photos and diagram are now in a PDF file I put together, and will distribute to others looking for guidance (attached for you to also have on file for sharing with others.
).
 

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Superbond

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I have read that AOD's for carbureted should be per 86. Is that so you don't need an added lever on the carb or is there another reason?
I have a chance to buy a Transmission out of a 92 Crown Vic police exceptor.
Is this a good AOD for my 72 351c FMX swop?Sorry for all the question! just want the right transmission
 
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Ford started putting modular engines in the Crown Vics in 1992, and they have a different bellhousing bolt pattern. You need to verify the engine type in whatever you buy, so they have the small block Ford bellhousing bolt pattern.
 

Superbond

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Ford started putting modular engines in the Crown Vics in 1992, and they have a different bellhousing bolt pattern. You need to verify the engine type in whatever you buy, so they have the small block Ford bellhousing bolt pattern.
I think it’s out of a 5.0L. If so that should fit a Cleveland no?
 

jakosaur

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I think it’s out of a 5.0L. If so that should fit a Cleveland no?
My FMX matches the AOD bolt pattern from a Country Squire, which only came with the 5.0L.
 

Superbond

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Thanks. I’ll have to call to see if it still available.
You wouldn’t happen to know what a police exceptor transmission means? Is it geared different or built heavy duty?
 

Superbond

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Just to be clear before I purchase this transmission.
A transmission out of a 92 Crown Vic with a AOD police interceptor package will bolt up to my Cleveland if it was matted with a 5.0L motor.
I was reading in google that 92 Crown Vic's don't come with 5.0L motors but 4.6L motors and that will not bolt up to a Cleveland.
just want to get this correct before I could make a mistake in a purchase :(
 
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That's correct, and is what I said in an earlier post, Ford started installing modular engines in Crown Victorias in 1992 and the bolt pattern is different. It's possible some of them still had the push rod 5.0L engine, you just need to make sure what the engine was. And, you need also to be aware that there is also a 5.0L overhead cam modular engine that also has the wrong bolt pattern.
 

Superbond

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So what is a good donor transmission? Crown Vic is out? Is there a code on the transmission that will tell me it is the proper transmission from a crown Vic?
What about a 88- 92 mercury Cougar or Grand marquis?
 
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I have a buddy offering me an AOD from a 94 Mustang 5.0, he is not sure about the bolt pattern. Any thoughts on this? My 351C has a carb, would I require a computer for the AOD? Thanks.

Tom
 

Superbond

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I don’t know if this would help you as I am in the same situation as you. But from all I have read on AID transmissions. It that in 93 they changed to AODE which means you would need a computer to control your transmission
 
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