I put the kit on my 1940 ford coupe and noticed that when you look at the car from the rear, the front of the springs angle towards the center of the car. Nobody really talks about that. Am I being too picky or what. I don’t like it.
That’s how it supposed to be. most parallel rear leafs are pointed to the center of the car at the front spring eye. Some more than others. Most are very slight. Look at the rear springs on a first gen Camaro or Firebird. They are noticeable.
Not being parallel actually makes the rear end more stable. When the leaf springs are truly parallel, then tend to want to lay over and shift the axle side to side a bit on turns rather then flatten out and act like springs. You can probably make them more parallel then they were designed to be, if you really want to, but I suspect you wouldn't be happy with the vehicle's handling. The parallel spring designation is a design as opposed to a transverse spring designation. It gives you an immediate vision of the spring layout. Even front parallel leaf springs are seldom actually parallel. Gene
This ^^^^^ A pair of deep arch [high load] leaf springs will want to roll over with lateral forces applied. If you had one spring straight ahead and one at 90 degs to that, one would stabilize the other laterally [but mechanically impossible due to spring arc movement] . If you pointed both springs inward 45 degs it would be the same scenario ^^^ [but mechanically possible] But they only need pointing inwards enough for the arc of the axle [during bodyroll] to pre-load the opposite side. Having springs in a "V" pattern removes the need for a panhard bar
I looked under a early 60s Thunderbird some time ago and noticed the taper at the front eyes; recently I did the same and looked under my 64 Fairlane, similar taper. Obviously done for suspension dynamics and handling
I have been running Posies on my car for 15 years with zero issues . The design allows you to set the stance the height you want it . They work great
What they call parallel is one spring on each side. As long as the springs work you are fine, so yes you are being picky
1957 Ford promotional materials highlighted the non-parallel rear spring positioning and the benefits thereof. I doubt it was a totally new concept then, but it’s the first time I ever saw it in brochures and ads mentioned as a benefit. Some of that taper occurs naturally as most chassis are wider at the rear and narrower at the front to accommodate the front wheel arc in turns. Some chassis, especially trucks, are parallel rails about two thirds or more of their length, then taper toward the front. By the way, even if the springs were equidistant in the mounts, when viewed from either end, they would appear to be closer at one end. It is a natural effect, which IIRC, is called parallax distortion. You can notice a similar distortion also when you view a dial face, a clock for example, at an angle, not head on. Ray
Maybe parallel with the side of the chassis but not with each other, I guess is what the term could mean. Since most old chassis rails kinder taper as they go forward... Worth knowing, as I have a back burner project with rear leaf springs mounted close to parallel with each other and I was heading towards making side chassis brackets, which I will now review keeping what I have just read in mind.
Sidebar: If anyone has a sketch of Posies brackets to use their parallel leafs in a 34 Ford, PM me. I have the springs, but no brackets. They made a standard mount, and an adjustable one; either style would help me out.
For a while there I thought I messed something up on my 47 Sent from my moto z4 using The H.A.M.B. mobile app
I used CE on my 40. Turned out well. Car drives straight and has a nice ride. I did take the extra time to measure 3+ times and shim to the frame where needed. I also up graded the the bolts from the kit.
I always thought parallel was parallel when I designing The rear suspension in my car. But the springs would not fit so I Angeled them a bit, I was worried about them until I measured a few cars and found out they are all angeled. Triangles are more stable them parallel.
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