The 54 cars had the same width as the 55/56 car, I put a 57 nine inch under my 54.  I am assuming the 52/53's are the same. Spring pads in the early Mustang  are the same as 54-56 as are the 57/58 9 inchers.  Not sure on the 59 rears.  Don't know about any of the other rears mentioned.





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I have the same Diff in my 55 Tbird, which is obviously not original. However mine has a 3.3:1 Ratio giving me better highway speed. 
When I posted asking for advice on what diff it actually was, I was lead to believe it was a 55, 56 shoebox.  
I recently fitted a Customline Pinion seal. 
The axles look fairly strong 17 spline about the same diameter as the 28 spline 9" axles.
 Any Idea if I posi-lock (LSD) can be found for one of these?

A reply to CK. My 55 Tbird has that rear axle and that is the way FORD made them. The 1959 Ford F150 came with a Dana 44 ( like the 55 Tbirds) and it could be ordered with a limited slip. The axles are 19 spline, not 17. Pete
PS. To be clear the 55 Tbird had a dana 44 and the factory rear axle ratio for a Ford O Matic car was 3.31. It is not a drop out. Sorry if I misled anyone. Pete

Learned something, thought all dana's were rear loading. Now I know.

Frank/Rebop

Bristol, In ( by Elkhart) 

Easy way to know what your rear end gear ratio is when everything is installed ( not the case here ) is to jack up the rear end ,put a mark on the drive shaft , turn rear wheel a full complete turn ( 360 ) and count the revolutions of the drive shaft. example :  one  full turn wheel turn = 3.5 drive shaft turns = 3.50 gears
giddy up, Carson

CK, I am now the proud owner of 2 center sections for the '55 '56 rear ends.  One 3.70:1 and the other 3.89:1.  Swapping center sections on these rears is fairly easy so I can see which one I like better.  I am curious about the installation of a new Pinion Seal in the '55'56 rear end.  The shop manual tells me to "Mark the position of the universal joint flange, nut, and pinion shaft with a punch to obtain the same pre-load when assembling the unit."  I am not sure where the marks should be placed. I think that the purpose of the marks is to ensure that the universal joint flange is matched spline for spline with its original position and to ensure that the nut is re-tightened to the same torque as it was found.  How does one know that the preload on a 60 year old rearend is correct as found.  This process seems to me that it could be a tad imprecise

Thanks.


Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Mark, The shop manual assumes that the preload was correct from the factory or re-build and you mark the positions ( witness mark) to get that crush, pre load back. It does not address the spline location. Pete

Pete, just to be clear, I mark the pinion flange and the nearest thread on the pinion with a center punch and then return the flange and nut to the same position and pay no attention to the torque value?  In order for this to happen I think the flange would have to be lined up with the splines as it came off - or am I missing something.

Mark

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Well i am not to sure if the pinion even had a collapsible spacer and the only tension at present is the lock of the nut.
I tightened it by feel, as i did my apprenticeship reconditioning diffs. Lots of 9" fabrications.
I also recently bought a 9" which i am converting to fit with 4 link.

So you are saying the 55 Tbirds were made with Dana and Banjo diffs.
my Tbird id says it was build no.247. maybe the early ones were built with the banjo.

I like the banjo style diffs to recondition. working on the bench is much easier than under the car.
It was such a smelly Job.   

Thanks CK.  The Tbirds, Station Wagons, Sedan Deliveries, Pickups came with the stronger Dana 44.  The cars came with the banjo style with the removable center section like a 9".  I forgot that you were working on a Dana 44 when I asked for your advice.  Sorry for the confusion.
Thanks.


Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia