1956 Ford Thunderbird rearend

B

Blue Moon

Junior Member
Is a 1956 Ford Thunderbird rearend the same as a 1955 Passenger car with a 272 ford-o-matic. Will it bolt right in, does it use the same leaf springs, etc.?

I'm going to be putting in a 302 with a C4, but i want this rear to rebuild and have it ready so when i do the swap, it's done.
 
The birds, wagons, and some trucks used the Dana 44 rear end. I believe all the cars used a different rear end, lighter duty, with a removable gear carrier. I know the spring perches for the bird and wagon lined up, but were different heights. Putting a wagon rear end in my bird back in the 60's required lowering blocks and the longer bird unbolts.

I still have the Dana in my 55 bird, although it apparently came from a truck, it has the larger axles and bearings. After 3 gear changes I regret not just biting the bullet in the first place and buying a 9" with a removeable carrier, or a modern rear end that fits. My understanding is that the pass car units won't take much abuse.

I don't know that this answers your question, but it's what I know.
 
I would recommend upgrading to a 9" housing 57 up. If you can't find a 57 T-Bird housing consider a 57-59 Ford housing which is approx. 53" axle flange to flange or an early mustang. You may end up moving spring perches but 8" and 9" drop-outs are much cheaper then the parts for the early Dana.
 
Last edited:
All the early TBird rears had a factory "lowering block" as part of the rear. My understanding is that 57 rears, whether a sedan or a TBird (both 9 inchers) are a direct bolt in on the 55 and 56 Birds, meaning the the spring perches are the same for sedans and TBirds. The sedan rears will require a lowering block when used on a Tbird as mentioned above.

If I am wrong about this, please correct me..
 
Both my 55 birds had the higher spring perchs welded to the axle tubes. The first one (1967) was probably original. The current one (I bought it in 1999) had what looked like "Monday morning" welds on the perch/axle. When I rebuilt it, it turned out to have the bigger axles and the appropriate bearings. The parts listed for a truck fit, I didn't ask if the wagon or other applications were the same. Probably explains why the welds were so bad.

When I swapped out the 3.3? rear end from the Fordo in 1968 (I put a T-85 o/d) in, I used a 4.27:1 out of a 6 cyl o/d wagon. Cheap lowering blocks with the bird U bolts got the car back to level.

I have no idea how many combos were out there, that's just my experience. But the bird back in '68 had different perches, not blocks.
 
miker98038 said:
The birds, wagons, and some trucks used the Dana 44 rear end. I believe all the cars used a different rear end, lighter duty, with a removable gear carrier.
Click to expand...

True, but put in different terms, the 55/56 Birds and Wagons had an "integral carrier housing" (Dana 44) which had an access plate in back. The car models had a 'banjo housing" type rear which had a removable differential carrier (pumpkin). I personally prefer the old style banjo housings, because if you ever need to do anything to the differential carrier, you can easily pull out the axle shafts and pull the pumpkin out entirely for servicing, while the integral housing types require all the service work to be done under the car unless you remove the whole rear end from under the car.
Just mentioning this for your consideration.
 
Thought I would weigh in regarding the Dana rears used.

The T Birds and the passenger cars all used the Dana 46 differential. It is the smaller bearings thinner axle baby brother to the Dana 44.

The 44 unit was installed into Police vehicles, wagons and sedan deliverys.

I'm sure many were swapped out into different applications therefore confusing what was used originally.

Parts are still ready availiable from the 4 wheel / 4 wheel drive suppliers.

Oldmics
 
Oldmics said:
Thought I would weigh in regarding the Dana rears used.

The T Birds and the passenger cars all used the Dana 46 differential. It is the smaller bearings thinner axle baby brother to the Dana 44.

The 44 unit was installed into Police vehicles, wagons and sedan deliverys.

I'm sure many were swapped out into different applications therefore confusing what was used originally.

Parts are still ready availiable from the 4 wheel / 4 wheel drive suppliers.

Oldmics
Click to expand...



Oldmics,

When I was young I had a '55 Mercury Montclair with the 292/198 HP T-Bird engine and Mercomatic. Is it safe to say this car had a Dana 46 and not a 44 ? I agree on the wagons. My '55 Ranch Wagon had "44" cast into the center section.

Sal
 
Sal

Unfortunatly I dont have a 55 Merc parts book to calculate part numbers from, HOWEVER according to the 56 book,Merc followed the same sort of installation proceedure.

That is only the wagons got the 44 differential in 1956 and the rest got the 46.

I would bet the 55s was the same.

Oldmics
 
I have a '55 Merc Monterey ( the car in my avatar); it has a Dana 45. It's basically a light truck axle but is a factory piece for Mercs in '55 and maybe '56. Was also used in Scrubby trucks through '58 or 9, plus other non FOMOCO applications. Parts are made of unobtainium but most Dana 44 parts will interchange with some creative shimming. If you google it you'll find some info on it.
 
Oldmics, thanks for explaining that. I had assumed the 44 designation went with the gear set. Your info makes more sense. I was one of those parts swappers, it all I knew was the ratio and if it fit.
 
It gets pretty confusing. Years ago I though they were all Dana 44's. Now I see there is a 41, 44, 45 and 46. Which I assume the Dana 44 is the strongest ?

Not to mention the later truck Dana 60, 70 and 80.

Sal
 
I think the 45 is maybe stouter than the 44. Axles are 2" diameter, 20 spline. Was used in 3/4 ton Scrub pickups, usually with 6 lug hubs. Why Ford spec'd that rear end is a mystery to me. It and the T-85 trans are much stronger than the low compression, low HP 292 in front of them. I don't think a 312 could hurt 'em either. It's almost as if they were anticipating someone swapping in an FE...?
 
Thanks for the info Dobie Gillis. I guess my old '55 Mercury Montclair had a pretty stout rear axle. Just like everyone else, I wish I still had my first car. I inherited it from my Father in '66 ,and my parents sold it after I got drafted into the Army in early 1970.

Sal
 
I know. I have a list of cars I wish I had now, starting with a '59 Sprite, '64 Beetle, '63 MGB. The one I'd give my LN to have back was a '57 Stude Golden Hawk I had while I was in the Air Force in the'60s. Had to sell it when I got transferred to Puerto Rico. That thing would pass anything but a gas station.
 
You must log in or register to reply here.
Back
Top