1938 alignment specs

[19Fordy]

Originally Posted by Ggmac

Yes that's shy all my posts , I proved I m an idiot ! But see post 13,15&16. Sorry my tablet isn't behaving .

Ggmac: You're not an idiot. It's great that your shared your experience from years ago. As a result, we all learned something new. Keep sharing.

[Ggmac]

Originally Posted by 19Fordy

Ggmac: You're not an idiot. It's great that your shared your experience from years ago. As a result, we all learned something new. Keep sharing.

Thanks . It really bothered me today , Its happening often . It stinks .

[JSeery]

Originally Posted by Ggmac

Thanks . It really bothered me today , Its happening often . It stinks .

Yep, been there, done that!

[19Fordy]

Originally Posted by Ggmac

Thanks . It really bothered me today , Its happening often . It stinks .

Wisdom is the application of knowledge to life's experiences.

You have gained plenty of wisdom during your life which you shall keep sharing with others. I'm 78 and also feel that 'stinky" sensation as the phone rings with
sad news about those I grew up with. Every once in a while I read the poem, INVICTUS by William Earnest Henley that we learned in high school back in 1961 and it puts things in perspective. Google: "INVICTUS".

[johnny]

I suggest that ford axles were factory installed with the axle information ie Ford ,part # etc.in the boss at the left front corner. Also I suggest that the front crossmember has a 4 degree forward angle. A lot of low caster is because the crossmember is worn so the spring has a bad fit. I have been told by old alignment guys that they would put a "axe" shim in between the crossmember saddle and spring .for consideration .

[V8COOPMAN]

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Originally Posted by johnny

I suggest that ford axles were factory installed with the axle information ie Ford ,part # etc.in the boss at the left front corner. Also I suggest that the front crossmember has a 4 degree forward angle. A lot of low caster is because the crossmember is worn so the spring has a bad fit. I have been told by old alignment guys that they would put a "axe" shim in between the crossmember saddle and spring .for consideration .

johnny.....I'm sorry, but I'm gonna burst that bubble! On any Model A through 1948 Ford with a transverse front spring, I-beam axle and wishbone, you could wear that crossmember completely OUT, shy of having it completely collapse, and it won't change the CASTER by one degree. The axle is solidly captured (not loose...NO movement) within the two forks of the wishbone. The axle CANNOT twist, or change it's relationship with the wishbone whilst being solidly restrained by the two perch pins. The REAR end of the wishbone has the ball on it which effectively 'locks' that end of the wishbone in the ball socket. The ball can rotate and twist in that socket, but the ball CANNOT move up or down. Because of the very geometry designed into the system, there are only two ways that the CASTER can change on the vehicle (besides smashing into something solid that bends the axle). One way to change the CASTER is to unclamp the wishbone ball retaining cap and physically move the ball end of the wishbone up and down. The other way that the CASTER changes is actually happening as you drive the car on an uneven surface that flexes the front spring. As the front axle goes over a bump, the spring allows the front axle to oscillate up and down. For the axle to move up and down, it must follow a very large arc. This arc is created by the wishbone ball being retained in it's socket. The front end of wishbones (and axle) pivot in an arc about that wishbone ball. So, even though the changes in caster angle are relatively minute, as the front end of the car raises (while axle/wheels remain at road level), the caster angle becomes MORE Negative (-). As the car hits a bump and the spring compresses, the axle becomes closer to the frame, effectively causing the CASTER to become MORE Positive (+). If my calculations are anywhere near correct, and with the distance measured straight between the center of the axle and the wishbone ball likely AVERAGING something near 42", EACH 1" of deflection up or down would change the CASTER angle by roughly 1.43º.

The transverse spring can stay clamped tightly in the transverse crossmember, yet still allow the minor changes in CASTER because of the flexibility created between spring and axle at the spring shackles. Those joints at the left and right shackles are very flexible. This is ONE reason why trying to shim the spring has no influence on changing the CASTER angle on a transverse spring equipped Ford. DD