When I was into 32 roadsters the 57 center appeared as a globe or ball cut in half , nice round smooth looking. Later years had shapes formed, also the 57 ranchero ha a larger piñon bearing. Don't know anything about the 59.
If they're both out of full size cars, (not wagons or Rancheros) nothing dimension wise, the 57's had the smooth housing, (no dimples) and are the ones most everyone wants.
'58-'59 had two dimples, and a flat strip over the ring gear. The first few years were not quite 9", so they are ever so slightly weaker than later ones. I cannot remember when this ended.
Good to know that Gimpy. Is the bolt pattern the same as 9" and enough room to put regular 9" stuff in it or do you need to replace the carrier?
there are small and large bearing end versions. I had both, sold the small one, the large one is in my Chevy II. works ok, but it did crack after a while...I added a strap across the back....probably not a problem if you have a more normal engine than mine.
IIRC the main issue was a lack of brake shoe area. 2" or so.The remedy was to use '63-'64 shoes which were wider..... 2 +1/2.I also heard it was tough to get a parts kit for them.Pins,springs and such. That was years ago when I was selling every one I could find. Maybe it's gotten better so correct me if I'm wrong.
Mainly depends on width of housing, as 9" are all quite sturdy. Jim Forbes' ('Squirrel') Chevy ll is an extreme example. I cracked one in '62, in my '46 with the old Joe Reath 331 Chrysler. 1:1 ratio 6-71, but I drove it like a gorilla. My '60 F100 rear has been in my '55 F100 for 40 years, (big bearing) never a problem pulling boats, hauling 2 Hemis at a time, my tool box, (!) and various other shop 'chores'. Did a 13.60 run at Baylands in '82, thru mufflers and street tires. So, it ran 'good', too. Love my 9"...er, 'axle'.
The brakes can be fun...the wagon rears with the large bearings also have slightly wider brakes, but I think they're 2" instead of 1.75? I put Chevy drums on mine, with custom aftermarket axles.
Two door and four doors used the 1.375 OD wheel bearing areas on the axle shafts. RW207CCRA bearing, 9568 seal inside the axle tube. Wagons and Rancheros used the 1.500 OD wheel bearing areas. 88128RA wheel bearings with 51098 seals in the axle tubes. If the axle shafts have slight rust pitting, torch, wear damage at the seal area, a guy can make the corresponding repair sleeve fit over the axle for a new seal surface after installing the bearing and retainer. The biggest oddity that I have seen on the very early '57 9" rears, is the use of an odd large OD pinion seal that I don't know the part number of. All of the stock later rearends, to the end in about 1986, use the common 7044NA pinion seal. As far as brake parts go on the car rearends asked about, good luck. I will give you a handy tip that I learned the hard way. Have your axle shafts checked for straight between centers on a lathe before you commit to using them. I have had to replace both of mine in the rearend I'm using in my A because of whatever had happened to the rearend that became the donor for my hotrod. I believe both had been twisted, because I twisted one off during an ill advised excursion.
From my recollections the 1959 9" diff measures flange to flange 53 1/2" and drum to drum 58" The long axle is 30 (or might be 30 1/2)" long and the short is 26" long. The 9" diff is famous/popular for having a 3 bearing supported pinion and a wide point of contact between the crown wheel and pinion gears. The weakness of the 9" diff that seems to occur in general use is that they can crack around the welds where the tubes meet the center housing. It seems to be one of the most common issues with them. If the diff is a wide say F100 style this cracking can be due to hauling very heavy loads for obvious reasons. However, I also believe that hard driving can cause those same welds to break/crack due to heavy acceleration and the bending effect cause by the wheels making traction and wanting to bend housing at the center portion. It is not that the welds break but the metal cracks along side the welds generally... Hence what experience Squirrel had is an exaggerated version of what I have just mentioned and his solution is was to add extra support to reduce that bending effect. The center portion is quite strong and so the first weak spot near to the center is where the tubes are welded to the center round housing. It is quite common to see this type of support installed in big HP cars.
Sorry but the rear brake shoes for Ford pickups are the same from 1948 to 1966 and are 1 3/4". Maybe you thinking of passenger cars?
I seriously doubt you'll crack (or bend) a housing out of a 57 F-100. Non welded tubes with 5/16" wall thickness.
I owned a 9" with the welded tubes that broke, so no doubt at all... The wider the diff the more leverage that can be applied with a load. I do understand your point with the fully stamped housing, that is a slightly different scenario.
this is where mine cracked. The yellow is magnaflux powder, the red outline is where it was cracked. and the brace I used to prevent it moving around so much. Haven't had any issues with it since, been a couple years.
57 to 59 are the same except for bearing size.Wagons,Retractable's and Ranchero's have the preferred larger bearings.
This is a '59 rear housing. This takes the smaller axle bearing (2 3/8") since it had a 6. The V8 cars and wagons had the 2 1/2" axle bearings... or so I have read.
Jim, I had one crack in the exact same place. I think sometime guys grind the welds down to get a clean look, but forget that this is not really going to work strength wise.
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