56 FordoMatic to Ford AOD?

[Philt]

Bought a 61 early this year and have enjoyed the perject and the driving. A friend bought a Minter 55 last year and turned it into a stunning car..major jealous issues.
A few days ago I bought a older restoration, nice driver 56. Loaded, PS, PB,two tops, ac and the Fordomatic. Working through its few issues but one I need help with.....intertstate highway rpm's. I believe it has a 3.31 rear-end and the three speed auto results in 75 mph and over 3k rpm. Sure 75 mph highways were almost non-existent in 56 but we enjoy the club drives and that often includes an hour or two on the interstate.
Anyone has experience with an auto overdrive conversion? My 55 buddy replaced the rear-end in his 55 for the same reason. Would like to keep the auto ( her car, her choice)..
Found an older website swapping a AOD into a 57 but there was x member cutting and frame rebuilding.
Phil in Tenn

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[Dale Leonard]

Whatever you do the Fordomatic is a good easy to rebuild transmission and is one of the few that has a front and rear pump. This car with this transmission can be push started due to the rear pump and it can be towed without damage if put in neutral. Since you are not drag racing then I would install a higher gear ratio in the rear end. This is just my opinion. Also the torque converter can be disassembled and cleaned.

 

[Philt]

Whatever you do the Fordomatic is a good easy to rebuild transmission and is one of the few that has a front and rear pump. This car with this transmission can be push started due to the rear pump and it can be towed without damage if put in neutral. Since you are not drag racing then I would install a higher gear ratio in the rear end. This is just my opinion. Also the torque converter can be disassembled and cleaned.

Thanks Dale, once the other issues are finished a , rear-end swap maybe the solution. Have had no luck finding a replacement gear set . Getting bit old for full restoration projects and this maybe be the last hobby car for her.

 

[Dale Leonard]

Rear Axle Codes
1955-1957: 1960: 1964-1965:
0 = 4.11:1
1 = 3.10:1
2 = 3.56:1
3 = 3.70:1
4 = 3.89:1
5 = 2.91:1
6 = 2.69:1
3 = 3.10:1
8 = 2.91:1
9 = 3.70:1
1 = 3.00:1


1958: 1961: 1966:
1 = 3.10:1
3 = 3.70:1
6 = 3.00:1
3 = 3.10:1
H = 2.91:1
(locking)
1 = 3.00:1
3 = 3.20:1
6 = 2.80:1


1959: 1962-1963:
1 = 3.10:1
3 = 3.70:1
4 = 2.91:1
1 = 3.00:1
A = 3.00:1
(equa-lock)
These are the gear ratios that were available for the thunderbirds. If you could find the code #6 for the thunderbird which is a 2.69:1 it would do what you need. Anyway that is the gear ratio that you need to buy for your car. If your ID tag is still on the car it will tell you what you have as far as gear ratio. Go to this address:
https://www.macsautoparts.com/ford_thunderbird/thunderbird-specs/

I copied and pasted but you have to go to the website to see the correct listing. Hope this helps you to order the correct parts for your car.

Another good site for info.

https://www.diyford.com/ford-axle-history-identification-ford-differentials/

 

[Philt]

Rear Axle Codes
1955-1957: 1960: 1964-1965:
0 = 4.11:1
1 = 3.10:1
2 = 3.56:1
3 = 3.70:1
4 = 3.89:1
5 = 2.91:1
6 = 2.69:1
3 = 3.10:1
8 = 2.91:1
9 = 3.70:1
1 = 3.00:1


1958: 1961: 1966:
1 = 3.10:1
3 = 3.70:1
6 = 3.00:1
3 = 3.10:1
H = 2.91:1
(locking)
1 = 3.00:1
3 = 3.20:1
6 = 2.80:1


1959: 1962-1963:
1 = 3.10:1
3 = 3.70:1
4 = 2.91:1
1 = 3.00:1
A = 3.00:1
(equa-lock)
These are the gear ratios that were available for the thunderbirds. If you could find the code #6 for the thunderbird which is a 2.69:1 it would do what you need. Anyway that is the gear ratio that you need to buy for your car. If your ID tag is still on the car it will tell you what you have as far as gear ratio. Go to this address:
https://www.macsautoparts.com/ford_thunderbird/thunderbird-specs/

I copied and pasted but you have to go to the website to see the correct listing. Hope this helps you to order the correct parts for your car.

Another good site for info.

https://www.diyford.com/ford-axle-history-identification-ford-differentials/

Thanks again Dale,
You are generous with your knowledge.
My 56 was a Jan mfg so it has the large data plate and no mention of the axle. But some reading suggests the fordomatic only came with the 3.70 . Change to 2.69 would a welcome reduction in rpm. So far no luck finding new gear set or in junkyards specific to a tbird. So maybe research other FoMoCo products with similar hardware.
Phil

 

[MRansom]

Rear Axle Codes
1955-1957: 1960: 1964-1965:
0 = 4.11:1
1 = 3.10:1
2 = 3.56:1
3 = 3.70:1
4 = 3.89:1
5 = 2.91:1
6 = 2.69:1
3 = 3.10:1
8 = 2.91:1
9 = 3.70:1
1 = 3.00:1


1958: 1961: 1966:
1 = 3.10:1
3 = 3.70:1
6 = 3.00:1
3 = 3.10:1
H = 2.91:1
(locking)
1 = 3.00:1
3 = 3.20:1
6 = 2.80:1


1959: 1962-1963:
1 = 3.10:1
3 = 3.70:1
4 = 2.91:1
1 = 3.00:1
A = 3.00:1
(equa-lock)
These are the gear ratios that were available for the thunderbirds. If you could find the code #6 for the thunderbird which is a 2.69:1 it would do what you need. Anyway that is the gear ratio that you need to buy for your car. If your ID tag is still on the car it will tell you what you have as far as gear ratio. Go to this address:
https://www.macsautoparts.com/ford_thunderbird/thunderbird-specs/

I copied and pasted but you have to go to the website to see the correct listing. Hope this helps you to order the correct parts for your car.

Another good site for info.

https://www.diyford.com/ford-axle-history-identification-ford-differentials/

My 1956 data plate has VIN, Body, Color, Trim, Production Code - but no Trans?

 

[Dale Leonard]

My 55 has the same tag as your 56 and does not tell the axle. I have the original rear end for my car and the 3 speed with overdrive. My axle was replaced with a boss mustang 4 speed and a boss mustang 4.11:1 and had a Honodrive overdrive bolted to the rear end which is a 30% overdrive. My car also has a 312 with 2 four barrel carbs. The guy that put it togather was going to run it at bonnevile salt flats. Working on putting it back on the road now.

 

[Philt]

My buddy with the 55 has changed the rear axle for a 74-78 V8 with auto Maverick 2.79 and says it is a direct bolt in swap. So lets start looking for for a Maverick axle...

 

[randy d]

Bought a 61 early this year and have enjoyed the perject and the driving. A friend bought a Minter 55 last year and turned it into a stunning car..major jealous issues.
A few days ago I bought a older restoration, nice driver 56. Loaded, PS, PB,two tops, ac and the Fordomatic. Working through its few issues but one I need help with.....intertstate highway rpm's. I believe it has a 3.31 rear-end and the three speed auto results in 75 mph and over 3k rpm. Sure 75 mph highways were almost non-existent in 56 but we enjoy the club drives and that often includes an hour or two on the interstate.
Anyone has experience with an auto overdrive conversion? My 55 buddy replaced the rear-end in his 55 for the same reason. Would like to keep the auto ( her car, her choice)..
Found an older website swapping a AOD into a 57 but there was x member cutting and frame rebuilding.
Phil in Tenn

Bought a 61 early this year and have enjoyed the perject and the driving. A friend bought a Minter 55 last year and turned it into a stunning car..major jealous issues.
A few days ago I bought a older restoration, nice driver 56. Loaded, PS, PB,two tops, ac and the Fordomatic. Working through its few issues but one I need help with.....intertstate highway rpm's. I believe it has a 3.31 rear-end and the three speed auto results in 75 mph and over 3k rpm. Sure 75 mph highways were almost non-existent in 56 but we enjoy the club drives and that often includes an hour or two on the interstate.
Anyone has experience with an auto overdrive conversion? My 55 buddy replaced the rear-end in his 55 for the same reason. Would like to keep the auto ( her car, her choice)..
Found an older website swapping a AOD into a 57 but there was x member cutting and frame rebuilding.
Phil in Tenn

Here are a few more thoughts you may wish to consider. The AOD swap onto the 312 is about $1g for just the adapters necessary to bolt up to the engine so when you add in the cost of the AOD itself it is pricey. Having said that, I have put an AOD into a 56 Fairlane Victoria and it is a wonderful swap. The AOD is smoother, less prone to leaks, and superior in every respect except for originality and cost when properly set up. If you drive it a lot you would be happy with it. If a differential swap is your plan because of cost or difficulty then I would suggest finding a 57 T-bird unit. That one uses the 9 inch gearset like the racers use so there is an unlimited number of gear ratios available and parts are plentiful in the event the one you buy does not have the ratio you want. While the later Maverick may fit, most are 8 inch gearsets. They are adequately strong but not quite so many ratios available. My 57 bird with Fordomatic has a 3.10 gear. I am considering another AOD swap but am going to give the original trans a try for the time being until I see how much driving we actually do with it. Good luck with your decision, and enjoy your cars!

 

[ShellyB55]

Is there a member here who has installed the AOD into a 55-57 TBird?? My 55 has trans issues, and going to an AOD makes a lot of sense. Would like to know the extent of frame mods. Thnx

If I do keep the F-O-M, any good shops , and can they test the trans before shipping??

SB55 in VA

 

[ron56]

I found a 3.07 ratio (listed as a 308) that appears that it will fit the Dana 44 rear end. (55 & 56 t-bird) One also needs a 26 spline yoke. It is going to be a winter time project to change over from the 3.31 I saw the listing from the NPD catalog and found the part number from Yukon YG D44-308 and there is a cheaper version from the same manufacture sold as USA Standard about $100. cheaper.

 

[Critterpainer]

Another option may be a 4R70W O/D as used in the later (within the last 25 years) Mustangs and also pickups I believe.

 

['55 'Bird]

I found a previous discussion about this but did not see anyone who has done this swap of a Ford AOD into a little bird. Mine is a 1955 and I am reluctant to modify the firewall of tunnel. Any help would be appreciated!
thanks in advance,
Steve

 

[74 Harley]

Hey Phil, I am more than a little curious as to what the problem is turning 3,000 rpm. These engines are designed for this. Unless the issue is noise or vibration I wouldn't change it. I used to fly my '61 for long periods at much better than 3K. (I am probably very lucky to be alive and have a license)

 

[Milton Lollar]

Bought a 61 early this year and have enjoyed the perject and the driving. A friend bought a Minter 55 last year and turned it into a stunning car..major jealous issues.
A few days ago I bought a older restoration, nice driver 56. Loaded, PS, PB,two tops, ac and the Fordomatic. Working through its few issues but one I need help with.....intertstate highway rpm's. I believe it has a 3.31 rear-end and the three speed auto results in 75 mph and over 3k rpm. Sure 75 mph highways were almost non-existent in 56 but we enjoy the club drives and that often includes an hour or two on the interstate.
Anyone has experience with an auto overdrive conversion? My 55 buddy replaced the rear-end in his 55 for the same reason. Would like to keep the auto ( her car, her choice)..
Found an older website swapping a AOD into a 57 but there was x member cutting and frame rebuilding.
Phil in Tenn

I am currently installing an AOD in my 59 bird, I built the trans as I worked for Ford 35 years as a transmission specialist, I now own my own shop. This swap was relatively easy with very few modifications. My only issue is a very loose lever on the end of the column where the shift linkage connects. My problem is finding disassembly information for the steering column