Thread: Model A rear susp.

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I want to lower the rear end of my Model A without having to have the framed Z'd. Is it possible or should I say is it wise to relocate the spring mounts from the top of the axle to the front of the axle to gain a few inches of lowness? I noticed most rods relocate the mounts behind the axle. Is one way better or safer than the other?

If you move the spring mount to the front or to the rear of the axle your wheels will no longer be centered in the fenders, your wheelbase will change.

Welcome to CHR, I am also a "New Guy". I solved this problem by buying a whole Brookville frame with the kickup already in it, but I have worked on other A frames. The spring mounts are directly over the axle in the stock A, but why would you want to keep the weak A rear? If you must keep the closed drive line (again, why?) you could try to find a '40 Ford rear (which is wider) which has the spring mount behind the axle and you could fabricate an extension from the back of the A spring arch to mount the '40 spring. A simple possible answer is to locate a rear spring from an A roadster which was much weaker and flatter than the high arch of the sedan spring. I believe there were originally several different size springs with the roadster the most flat and the sedan with the highest arch. Messing with springs can be dangerous and if one kicks out on you it can break an arm easily, but suppose you had the high arch spring and a roadster spring off the car, you could beef up the roadster spring with one or two of the short leaves from the sedan spring. This might give you 1 1/2" to 2" drop. However most of the aftermarket A springs are the high arch type so I do not know where you can find the flatter roadster spring. In the '50s the '40 rear was the standard answer to this problem. Now I would say if you bought a four-bar kit from one of the aftermarket groups you could use coil-over springs with shocks inside the spring and then set up a fourth lower hole in the spring-shock mount by welding a tab on the bottom of the spring mount. However, my best answer is to convert to an open drive line with an 8" Maverick rear and install a four-bar kit. I would try to use the lowest of the three mounting holes in the four-bar mount first and maybe that is already low enough so you would not have to change the mount at all. Summary: 1) get a flatter spring and install it with care OR 2) go to an open drive with a Maverick rear and install a four-bar to use the lowest hole on the shock mount of the coil-over springs. Another possibility is to make your own triangulated four-bar mount and use a Chevy S-10 truck rear similar to what brianrupnow has shown with pictures for the frame of his A-pickup.

Don Shillady
Retired Scientist/teen rodder

Hi, Evidently the "SEARCH" feature is working now. I thought about some other things after the first response. After remembering a bit I think the '40 rear installations in Model A frames that I saw still had the spring over the axle with brackets welded on the axle housings of the "banjo" rear. I wanted to add (later) that maybe a flatter spring could be found AND that the eyes of the spring could be reversed and that should lower the spring and body by about 1". Thus if you keep the spring over the axle I don't see how you could lower the body any more than about 2". You did not say what you are trying to do, rod, resto-rod ? Long ago I put 17" wire wheels on the rear of a '31 Tudor and left the front wheels at the stock 19" to give a "sit down rake" but of course that is a simple adolescent trick and while I thought it looked cool, the appearance is entirely subjective. At present I am installing coil-over shocks at the rear corners of a Brookville A-frame with a built-in kickup but so far I do not know how firm that will be or which of the three holes I will use for the mount. In my older age I would now favor jacking up the rear a bit so it is purely subjective. Overall just try to take off the top two leaves of your rear spring (carefully) and then get the eyes of the bottom leaf reversed at a spring shop (heating, straightening and then reverse rolling), that should give you a lowering of about 1 1/2"; otherwise try a four-bar.

Don Shillady
Retired Scientist/teen rodder