Posted by Joe Lorenzino on Thursday, July 22, 2004 at 3:09AM :
In Reply to: 1/2-track photos, paging Fred and other experts posted by Don in Missouri on Wednesday, July 21, 2004 at 4:10PM :
In reverse order:
The lever on the shifter looks like a standard Ford truck 4 speed "reverse lockout". My 1942 Ford trucks have them, and I would guess they were used both before and after that time. Reverse is "locked out" until you lift up on the little lever, which allows the shifter to move sideways into the reverse gate.
The double wishbones are probably an attempt to correct the caster angle on the lifted front end. Lifting the truck that much would have made the caster angle go over center to a significantly negative value, which usually results in "ditch to ditch" steering. Adding the second wishbone on top of the first would lower ball end of the original wishbone and thereby bring the caster angle back somewhat.
As far as I know, ALL the Ford trucks up to about 1946 or so used that type of torque tube rear end design. The ball end mounts through a separate cross member about a foot or so back from the rear of the transmission. There is a short, double u-jointed drive shaft that runs in another tube from the trans, back to the ball socket.
The rear axle looks like a Ford unit of the time. Ford used that style of split apart rear axle under their trucks for many years. That one looks a bit larger, so it might be from the same manufacturer (Rockwell?), but for a different application. I have never seen a “high cowl” 30-31 model AA truck, so I do not know what type of rear spring system they used, but the early 28-29 models used a “cantilevered semi elliptic” system. (not a ¼ elliptic, …the 490 Chevy used that I believe ) The 32 and later trucks used a normal semi elliptic spring, BUT with shackles on both ends, and a swivel mount on the axle housing. Maybe the springs are under the frame on this ½ track because they have been moved inboard so that the track guide mounts will pivot on the axle housing where the swivel spring mounts used to go? Because the rear end still has the torque tube, it needs to move back and forth as the suspension compresses, so the springs must be free to move lengthwise at both ends. Ford used shackles at both ends; this machine looks like it uses “sliders” instead.
These answers are a reasonably good guess based on what I could see in the pictures. J.V.L.
Follow Ups: