Featured Projects Fordomatic to AOD Swap

I read you use gps speedometer.
Why? Your old speedo cable/gear should fit aod just fine and new different gears are avaible to adjust speedo.
I have swapped aod to 64 galaxie and 63 fairlane and both fits directry.

 

The old speedometer is hooked up and working but there is not a gear that will make it read accurately with the rearend gears I have.

I had to buy a new cable and change the speedometer gear to work with the AOD. The Fordomatic is different than AOD, but AOD would have a similar a cable and gear to your later fords.

Also we use Kilometres here so it’s a pain to constantly be calculating the conversion when driving a car with a speedometer that is not accurate and in miles. The GPS speedometer reads in Kilometres so it’s just easy. When I’m approaching a speed camera I don’t need to be trying to calculate what 50km/hr is on a speedometer that is 15%off and in miles per hour.

 

Fairlane was original 2speed fordo and speedo gear and cable fits directly
Galaxie was cruisomatic and i use set of c4 speedo gears to set speedo reading right.
C4 speedo cable gears are made something like 6 different tooth count and they all work same output shaft gear.sounds grazy but thats how it is.
Ps, we have kilometres here too.
Here we have had km speedos in american fords and mercurys which have imported when new.

 

I think the AOD has the speedo drive gear rolled into the output shaft, so to change it one needs to change the output shaft, a major pain.
Also I think there were only two "drive gears", integral with the output shaft, available, unlike the older transmissions that had a variety of plastic drive gears both left and right hand, available and fairly easy to change.

 

I received new flexplate and it’s actually worse than then first one.

so new plan is to mount the flexplate in a lathe and use a grinder to trim the teeth slightly.
I don’t like it but it’s the only solution I can come up with.

It’s just that the teeth on the flexplate are too long by a fraction of an inches

 

I know speedo gear is rolled in the shaft.
I know there is two differen tooth versions.
I also know there is no need to change these.
Only speedo cable gear need to change.
There are set for sale with different gears.
https://www.cjponyparts.com/speedom...aode-automatic-transmission-1965-1973/p/SGK2/
But you dont have to believe me.

 

This will do the job but from what I can find they are pricey.
Speedometer Calibration Gear Box - Corrects your Speedometer
https://www.ihpartsamerica.com/stor...K8_AcAKV_oHqLzwHkSN5AQs7wrOH94M4OGXGsffhT540G

 

Wow, that’s more than the speeding ticket would be

 

I did a fair amount of work on the flexplate and I think it’s good to go now.
There was a bad spot that I had to remove quite a bit of material to get rid of but now the starter engages in all positions and sounds a lot better.

next will be to start the engine and make sure there’s no vibration as a result of the flexplate work.

 

Sorry you had to go through all of that but thanks for posting it. I have three engines with adapter plates and custom flexplates (2 Pontiacs and one Chrysler). I will definitely be checking them before buttoning them up. I’ve never seen that problem before but these days it’s not surprising.

 

I build ratio adapters for calibration mine run $145.00 for the same adapter. Just need a measured mile reading to do it properly.
Check the calibration page on my website for the reasoning on the measured mile reading.
It’s also the best way to go about speedometer driven gear changes.

 

With high differential gear ratios it is not always possible to get the correct ratio even using the highest tooth count driven gear available. For instance it might require a 24 tooth gear but the highest available one is 21, as shown in your link:



The solution would be to use a drive gear of tooth count that would allow the speedometer to read correctly using the available driven gears.
I was pointing out that this would be possible with the earlier transmissions, but not so with the AOD.

Here are examples of the type of removable drive gears used on earlier transmissions (available in other tooth counts):

 

https://www.summitracing.com/parts/tci-881004
There are 23 tooth version.
I have done it with 3.55 rear and aod.
If its impossible to you, its not for me.

 

I need to make it more of a habit to check new parts thoroughly. It’s not unusual to get brake rotors that are warped out of the box and new starters that don’t crank.
When I installed this engine I used a rebuilt distributor. Several people on here told me the condenser would be junk and I didn’t listen. That new condenser left me waiting for a tow truck the second time out.

Unfortunately I waited until the transmission was fully installed before checking the starter and flexplate. Lesson learned.

 

Once again @e1956v comes through. IMO

 

glad you gout the flexplate sorted. it really a shame they build and ship part like this. But I guess it is a welded up piece so there is that. Machined would be too costly for most folks.

 

I’ve seen a lot of questions about starters on the AOD swaps, but this is the first solid answer I’ve seen. Makes me wonder. I’m not looking for you to criticize anyone, but would you comfortable telling us who’s adaptor you’re using? If you did I missed it.

 

The adapter is from Performance Adapters.
The flexplate is an off the shelf part that comes in the kit. I don’t blame the guy making the adapters, he has no way to know the parts he includes are built wrong.

 

Thanks. I wasn’t looking to place blame. All I care about is getting it done, which you are.

 

Engine runs and no vibration from the modified flexplate!
Time to put the transmission back in!

 

Why don't you recalibrate the speedometer to read KPH instead of MPH?

 

Here’s what the fordomatic and AOD speedometer gears look like. Obviously not interchangeable.

 

look who’s outside!

Woody just made it back from a test drive and everything seems to be working great!
It shifts nice, doesn’t leak, doesn’t sound weird,
No vibrations and the Brakes work,

and as a bonus the original speedometer is more accurate than it has ever been so I’ll probably ditch the gps speedometer after all!

 

Great info in this thread! Happy ending is always a great ending!

 

Tell again, what rear end ratio you have and what speedo gear you use?
I gues 21 tooth.

 

@AldeanFan you take it on the highway yet?

 

3.45 gears
I believe it has a 19 tooth gear - it’s a grey/beige colour.

 

No highway yet,
My test drive route is 10km on country roads and I did get it up to 100km/hr or about 65mph.

 

Great write up. Thanks for taking the time. Nothing like success.