Do all 57s have 9 inch differentials?
Yes, except the trucks.
Yes. The rear end was a new design for 1957. It moved the pinion gear down in the carrier to lower the driveshaft. This allowed a lower tunnel/floor allowing a lower design for the car. It also dramatically increased the strength of the rear end. "Longer, lower, and wider" design theme for the first time.
Quote from: Ford Blue blood on 2021-06-23 07:54
Yes, except the trucks.
57 and up 1/2 ton F100 had the 9" also, housing was different but the 3rd member was the same. F250 had Dana..
Quote from: hiball3985 on 2021-06-23 12:03
57 and up 1/2 ton F100 had the 9" also, housing was different but the 3rd member was the same. F250 had Dana..
X2 What Jim stated. I like them so much better than the Dana.
Yup, you guys are correct. Forgot, my 73 had a "N" 9" in it, the 48 was a Dana.
How far into the 60's was the nine inch used on all full size Ford cars? I have 57's, 58's, 61's, 63, 76 and every last one had a 9 inch, no matter whether a 6 cy or 8 cyl. Granted most were either Y block or FE motors, but I have a base model 61 stripper 4 door with a 6 cyl that is also a nine inch. The only variant to that I have noticed was the 8 inch in Fairlane and Torino in some smaller cars with small motors getting the 8 inch instead. So, there were many years where a 9 inch will be found in virtually every full size Ford, not just 57's...
9" in later models, yes, but some are wider than our '57s.
Quote from: RICH MUISE on 2021-06-24 14:23
9" in later models, yes, but some are wider than our '57s.
Rich I think he was asking about the 3rd member, I maybe wrong. So yes the axle housings are all over the place depending on year. The 3rd members are mostly interchangeable except some models used a different axle spline count. Just as a note the 57 3rd member was a one year only design but you can use a later one. Not sure when the design changed? Mid/late 57 or not until 58.
Yep, "differential" to me means the gear carrier and its components when the topic is a Ford 8" or 9". Probably means different things to different people, but I replied on that basis because the OP had used that terminology, differential rather than axle. If we were talking about an 8.8 differential I would however be inclined to think "differential" ="whole axle" cuz no dropout carrier. Just how I refer to them.
Ford did install an integral style rear axle assembly, in full sized cars, with a cast center casting and a sheet metal cover, similar to a 10 or 12 bolt Chevy, or 7 1/2 or 8.8 later Ford. Not sure when they started using them, but I know a guy with a 69 Galaxie with one. I believe they were called an 8 1/2". Ford also used a 9 3/8" "drop out" , similar to a 9", but slightly larger, yet weaker at the same time. The 9 3/8" was commonly used in big Fords, Thunderbirds and Lincolns. Every one that I have seen was 31 spline, and often had a limited slip unit, but only with tall gear ratios, often 2.80 or 3.00. The 9 3/8" 3rd member will fit into a 9" housing, if you notch the housings gasket flange to allow the larger ring gear to fit. But with the weaker casting, and limited ratio selection, not much reason to. As for swapping different 9" center sections, in addition to 28 vs 31 spline, other things to keep in mind are some cases have a filler plug for checking and adding gear oil, but some housings had the plug in them, so they are lacking a fill plug in the cast case. So you could potentially have 2 points to add fluid, or none. Also, Ford used a wide variety of driveshaft pinion flange yokes, with different sized U joint cup diameters, widths, and U bolt sizes, as well as a number of different flange lengths.
Lots of good points made about the differences. I had to use one without the filler hole one time years ago and required adding the lube through the axle tube before installing the axle and with the car jacket up higher on one side :005:
Yup, I learned the fill location lesson long ago. :002:
I believe '60-up was the change.
I suppose the vent or a removed stud's location could be used as fill point also?
Jim, about 25 years ago I had to fill my diff. the same way. Pulled the axle and put in correct amount of oil, and am still driving it today. Never has leaked so I guess it is still ok.
:003: Put the car on a rotisserie...flip it over...fill the diff via the drain plug...flip it back...drive on. :005:
Just kidding...my mind is a bit warped today...okay...EVERY day...but I had to it out today! :002:
That is a really good point to remember. Have not encountered it myself, but if I do then welding a fill bung on the housing prior to axle assembly would seem to be the way to go.
Quote from: mustang6984 on 2021-06-25 10:10
:003: Put the car on a rotisserie...flip it over...fill the diff via the drain plug...flip it back...drive on. :005:
Just kidding...my mind is a bit warped today...okay...EVERY day...but I had to it out today! :002:
Thinking about that a bit...
Actually a diff could be filled via the drain plug.
If a clear hose was temporarily "plumbed" to the drain hole even the correct fill level could be determined before quickly swapping in the drain plug.
That's not too different from how today's transmissions without filler-tube are topped off.
I just dug out all my 9" spare parts to see if I could assemble a complete carrier. The empty carrier I found had no fill plug. It drilled easy on the drill press and tapped it 1/2" tapered pipe. Problem solved. The other means of filling would require measuring the fluid. A pint over full is good but too much and the axle seals will likely fail.
And I was just being a smart-a$$...LOL!!!
So was Goodyear when he accidentally developed pasteurized rubber. :002:
But through-the-drain fill would work and with accurate level check.
Of course Gasman's drill and tap is the pro way.
I did exactly that (drill and tap) when installing a 3.00 in my Ranch Wagon. Worked perfect and never leaked. Never did do a "stress test" as tires and parts cost too much......
The center (section is the differential ) on a 57 housing is not 9 inch opening for the ring and pinion it is 8 3/4 . Most openings are for 9 inch ring and pinion in later years so later housings that are notched from factory mine was not and it is original from factory 57 28 tooth splined axles I used a 1970 mustang center (differential) section with 2.75 connected to c4 I also had to notch the housing half a penny size top and bottom so the ring gear and the gasket so it would clear the housing . As far as the depth of the pumpkin it is 3/16 in back clearance for the ring gear and used the same factory axles 28 spline and the differential. And one thing the that Ford forgot do was no drain plug on later Fords my 57 has one so that being said I always put one in the housing one of many street rods I've done so much easier to do when your doing your project. Lot easier than pulling the center section and axles to change the gear oil It took a great friend and thinking to get installation done and figure it out why the ring gear would not clear the opening housing and LOTS of measuring .
I have not noticed the "notch". I just put a mid 70s 2.75 in my 58 Pacer. The paper gasket had no notch and the 70s center section slid home the first try.
I have discovered that later Lincolns and Bird 9" rears were in fact 9 3/8". They will fit into the original 9" housing with a notch and bolt up. Their most common ratio, 2.75.
If you look up gear ratios in mustangs in the 70s 2.75 with a c4 was factory common as for driving great highway cruising ratio. In fact youtube has pictorial showing them notching a housing with no structural integrity . The lip of the housing is 1/4 " thick and your right about the gasket I had to notch it. Hope this helps the next person on this site.
I had the ring and pinion changed on my car by a friend who owns a gear shop. He put in a 3.25 ring and pinion in my car with 31 spline axles. If I remember right he had to notch the housing. The 3.89 gear came right out.