I have some questions about swapping a 9' From a 57-72 F100 into my 1954 F100.

1) Is this really just a bolt on, i..e. no welding required?
2.) Are any years better than others?
3.) I am looking for 3.23 gears should I be looking manual or automatic.

Please comment on anything else I should be aware of.

Thanks for your input

Marty

 

Try to get the top plate that goes on top of the springs that the U bolts come up through. You will have to change the shock mount locations (on the axle housing) which isn't hard to do. You will need new U bolts. While your at it, grab or keep the 'e' brake cables and drive shaft, you might need the yokes. Check the tag if its there for the gear ratio. Any of the years you posted should be fine.

 

Mervy pretty much covered it. The taller ratio gear you want will be more likely found in the later model rear than the earlier...

 

You may need to use caster shims between the bottom of the rear springs and the top of the mounting plate on the axle. The pinion angle needs to be the same as the engine angle.

 

Thanks for the replies so far. I read a post on the HAMB that the drive shaft needed to be altered because it was short and the best years to use for compatability were 1957-60. Are these two items correct.

 

It is basically a bolt on swap. You dont even need to re-locate the spring mounts if you use 1958 or 59 shackles. Yokes on the 9" have a couple different cup sizes for the u-joint so if you find a smaller one it is the same size as the oem axle yoke. YOu may have to have your drive shaft shortened/lengthened.

Find an axle from 1969-72 and the over all length of the axle will be the same also. easiest swap for a rear there is and the gears a super easy to change. the third member just pulls out and you put a different one in. Bullet proof

 

Yeah driveshaft may need to be altered, depending on your drivetrain and how it's positioned/mounted.

The '57-'60 would be choice just because the mounting hardware would make it a direct, no mods, swap. The 9" axle itself is basically exactly the same from '57-'67, brakes and all. In '68 the axle changed a bit to allow for wider brake shoes up to '72. This modification didn't alter the overall width though. All the 9" axles from '57-'72 share the same overall width. The difference in the brake width change was made up within the axle itself.

 

Did the axle change or did the backing plate change (deeper dish/more offset) to accomodate the wider brakes?

 

Backing plates were dished inwards

 

Yes, but that didn't happen until 1968. Through '67, the same size rear brakes was used from 1948.

 

Actually I need to qualify my answer above. I put my D44 brakes, complete, on the 9" and the drum was sticking out proud of the backing plate by 1/2". That implies the backing plates were not changed. At that point I didn't go any further, just used the 9" brakes. Just looking at them the 2.5" backing plates certainly appeared to be dished more than the D44's 2" plates.

 

The axle housing is definitely narrower as well as the backing plates had more offset on the '68-'72 axles. Why Ford didn't just do one or the other is beyond me. One of those Ford "Better Ideas" they used to advertise all the time.... You jump to the '73 axle, everything is the same and just the axle housing (and axle shafts) itself is wider. Guess they got a clue and did it right that time.



Right, now I'm not sure on the '57-'67 9" rears. The Dana 44 brakes may fit just fine on those axles as the 9" in those years shared the same 2" width shoes. Never tried it, so not sure there. I do know for a fact the '68-'72 wont, just as you noticed. I too ran into the same thing. What ford did for '68 was reposition the backspace of the wheel bearing on the shaft, and changed the offset of the backing plate to accommodate the wider brakes. Now somewhere along the line Ford changed the actual width of the axle housing itself and to keep the overall width of the axle the same, they put the difference of change into the backspacing of the wheel bearings on the axle shafts themselves. I measured a 1960 housing and compared it to my '68-'72 one I had, I'd have to go and find my notes but there was an inch or better in difference, just in the housing itself. Now WHY Ford would waste their time with this....? that's the million dollar question.


Here's a picture to illustrate kinda what I'm referring to (Both are 9" axle shafts out of trucks one early, one post-'68)

 

1957/67 F100 9" 28 spline axleshafts are the same (B7TZ-4234-A).

1968/72 F100: There are two different 9" rear axles. One has 28 spline axleshafts with/without Limited Slip.

The other has a 9 3/8" ring gear, 31 spline axleshafts and 4 pinion Traction-Lok.

Only 5 parts interchange between the 9 & 9 3/8: Housing gasket, pinion seal, one pinion bearing and cup, pilot bearing retainer.

EVERYTHING else is different! Parts for the 9 3/8" can be difficult to find.

1968/72 F100 rear brakes are the same: 11" x 2 1/4" / 1948/52 F1, 1953/67 F100: rear brakes are 11" x 1 3/4"

Mid year 1969 9" (not 9 3/8"): Ford changed the differential bearings from ball to "slim line" tapered roller.

Warranty Plate AXLE code for 3.23-1 ratio w/o Limited Slip: 1965 = 07 / 1966/72 = 17 / FoMoCo didn't offer a 9" with Limited Slip in F100's until 1968.

1965/72 F100: 3.23-1 commonly found with A/T, very few M/T's came with this ratio.

1965/72 F100's with a two piece driveshaft have a u-joint that has (2) 1310 cups, (2) 1330 cups: Ford: C5TZ-4635-F / Spicer: 210392-X