front spring perch mounts

T

town sedan

Junior Member
The holes in my 1930 fordor front axle for mounting the spring perch are worn. I wonder if anyone is repairing such; perhaps boring the hole and pressing in sleeves? Otherwise I think I can only search for someone ditching their from axle for a Mustang 2 or a drop axle. Has anyone heard of such a repair?
 
town sedan said:
The holes in my 1930 fordor front axle for mounting the spring perch are worn. I wonder if anyone is repairing such; perhaps boring the hole and pressing in sleeves? Otherwise I think I can only search for someone ditching their from axle for a Mustang 2 or a drop axle. Has anyone heard of such a repair?
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You really do not need to worry about boring and bushing. You can just use shim stock to wrap the shank of the perch to take away the slop. The taper on the top and bottom of the Radius Rod is what locates everything.
 
its an easy job for some one with a milling machine, bore the hole true, press in a sleave,and bore that to size.
I would be very carful doing a bodgy job on this area ,it is very important for locating the axle ,and keeping it in line when the brakes are applied.
Ask me.
Lawrie
 
I have the same situation and made a shim out of duct sheet metal.
I also removed the ridge around the boss on the axle and wishbone which that required a shim be made for there -.037” on one side,the taper on the nut was worn too.
The top of the spindle was worn and it wasn’t flat so I made a recess for a hardened shim ( Mercedes steering gear washer) along with kingpins ( NOS), new steering arms ( NOS — don’t trust welded on balls),Steering gear inspection/adjustment on the bench centering it to straight ahead optimization.
 

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town sedan said:
The holes in my 1930 fordor front axle for mounting the spring perch are worn. I wonder if anyone is repairing such; perhaps boring the hole and pressing in sleeves? Otherwise I think I can only search for someone ditching their from axle for a Mustang 2 or a drop axle. Has anyone heard of such a repair?
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A machinist gentleman of my acquaintance was working on a later Ford axle in the manner which you seek. He was boring out ALL four holes in the axle and pressing in "sleeves" which when done would present the proper angles. He was doing this on a Bridgeport vertical mill and it was a challenge to "do one side" and have fixture to be able to shift everything to the right and do it in mirror image.

The kingpin holes (IIRC) are 4 degrees tilt in, the spring perch/kingpin holes were 90 degrees to their orientation across the wishbone? Caster is found in the wishbone.

He was doing this to correct somewhat for a "bent" front axle - IIRC, the flaw was the typical "passenger side" push back (i.e. hit a pothole at the edge of the road) - which he had straightened to bring the holes into alignment, but found the "camber" uncorrected was not correct and felt this was the best way for him to "bring it back".

Alas he's not around now, having passed in the 2010s.

Somewhere (Internet) there is a drawing of the front axle which shows the necessary angles.

I stand corrected (above 4 degrees) More, perhaps better information on camber/caster/toe at https://files.secure.website/wscfus/10576359/26724602/modela-frontend.pdf

As to another axle being "better" as in not bent - this is part of the crap-shoot of used parts. You may find it worse.

My contention has been ALL Model A axles are bent typically on that right side.

Joe K
 
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In addition to bent (fore and aft, as Joe K describes) most Model A front axles I've had the pleasure of meeting are also twisted (kingpin holes and spring perch holes are not parallel in the cross-axle dimension). These are easily evaluated using winding rods - cone-shaped inserts on straight rods that insert into the holes. These devices were an era tool but I made up a couple of sets from 1" round bar, tapered on the lathe, and 3/8" rod about 3-1/2 feet long. You clamp the axle firmly, sight the tops of the sticks with string, and then apply persuasion where the twist is (see photos of a club seminar we had last year, the axle was clamped to a big piece of I-beam which in turn was clamped to that 6x6 column). This can easily be done cold with a long enough cheater bar on the pipe wrench.

I think if you are going to rebush the spring perch holes or the kingpin holes you should check this after you are done.
 

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This can easily be done cold with a long enough cheater bar on the pipe wrench.
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ALWAYS bend cold for this kind of correction - lest you upset the "metallurgy."


I've seen them and many swear by them, but one wonders about the strength of so called "lowered" front axles.

023-kohler-dropped-axle-comparison-660x438.jpg

Z



Joe K
 
There is a guy a few miles from my place (an ex hotrodder) who bends and straightens axles as the owner requests - COLD. I have had 3 axles done where he removed a slight twist and shrunk the king pin holes so they were a good fit again. I'd be amazed if there is nobody over there who can do the same - mqybe one of the hotrod shops.
 
The question was can the holes be bushed back to correct size? Yes it is possible. Back in the 60's we had several GM axels done for school bus repair. I would look for a better used unit.
 
Town sedan - there are plenty of salvageable axles out there. It might help if you posted your location. I have a dead straight axle and wishbone with a good radius ball that I’d be happy to part with.
 
Bigsnapper43 said:
The question was can the holes be bushed back to correct size? Yes it is possible. Back in the 60's we had several GM axels done for school bus repair. I would look for a better used unit.
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That was my query to the machinist I mentioned above.

"Don't you reduce the strength of the axle by doing a bushing?

Ans: "Yes, but the majority stress comes at the "skin" (exterior "chord") of the axle (same reason I-beams are "H" shape - to match the ability of the beam to resist tension/compression to the actual force encountered in loading.)

I suppose one could make the argument that forces are not always "aligned" to the orientation of the holes - so his reply might have been "overstated." But he says he has done many and had never had a complaint of a bent axle.

Ford WAS notorious in those days about "generous" engineering. Mostly.

Joe K
 
katy said:
What is the correct torque for the spring perch nuts?
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Based upon what I've had to do to disassemble, I'd say - tight! Then tighten some more to line up the cotter pin holes. Probably overkill, but I used a 40" 3/4" drive breaker bar on the front end I just built. I would guess I'm somewhere north of 100 lb-ft.
 
katy said:
What is the correct torque for the spring perch nuts?
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Les Andrews (Brown Model A Mechanics Handbook) calls it 100 ft-lb.

One online source at Fordbarn calls it 250ft-lb.

Based on the size of the threaded shank (5/8-18NF) Fastenal gives many numbers depending on lubrication ("K") and bolt grade (i.e. "quality")

https://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf

Gr A 54-72
Gr 5 127-170
Gr 8 180-240
Gr 9 211-281

The "lower" torques here are for the "more lubricated"

100-125 might be a good number lubricated?

Joe K
 
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