Trying to hang my '27 T on a Model A frame. Got the drop brackets made, just need to know what center distance to weld them at. The spring, with 2 leaves out, is 42.5" eye to eye as it sits. Got an old banjo rear axle and that is 49.5" but not sure if that would be right being that I'm shackling it down behind the new axle. What's the rule of thumb on this? Thanks!
Are you using a "T" spring, or "A" spring? Also makes a big difference when you get the full weight of the car on there if you removed leaves. Did you take long or short ones out?
Just a thought, but have you considered that mounting the spring behind the axle is going to shorten the wheel base of the car? May not matter if you are using a T body. But would put the axle too far forward in the wheel wells on an "A"
This may help give you some idea: From "Speedway": Medium Arch Transverse Rear Leaf Spring, Reverse Eye, 38 Inch These universal transverse rear leaf springs are perfect for those wanting to build a tradional looking T-bucket or early Ford style hotrod. Each cross spring is made from high grade tempered spring steel and is 2" wide, 38" from eye-to-eye and has 5 leafs (each 0.25" thick). Each leaf also features rounded ends for a smooth, finished look and comfortable ride on lightweight hot rods. With the help of reversed spring eyes, this spring measures 10" high to the inside of the arch, which makes it ideal for low-slung hot rods. Spring eyes are 3/4" I.D.
It's an A spring. I took out a long leaf, skipped one and took out the next also. Was going to set the rear end behind the spring but was getting interference with the pumpkin. To go far enough back to clear that made my wheelbase too long for my pickup bed. I have a full sized model A bed that I plan to cut down to 48". I could go longer but it starts looking too Jethro. So, putting the rearend in front of the hump looks to be my best option short of Zee-ing the frame which I'm not going to do on this build. Thanks for the chart.
A stock Model A rear end has the hangers 50 1/2", outside to outside of the HANGER, not the bushing if that helps. Edit: Sorry, just saw you have measured a model a rear end. Well.. above still works lol. I just did a spring over setup on a '48 Merc rear end, using cut off model a perches the way "Chris" did it, there is a thread for his setup on here. I also used the original shock mounts but put them on the front of the diff, and used an inch spacer for one of the perch sides. It worked out perfectly. I just set it at the same width as a model a rear end, as its going into a model a, and i used a model a rear spring.
Just went through simliar issues on two "A's" that were spring over axle setups. Was trying to lower the car as much as possible, soften the ride, but still not bottom out. Did not want to modify the chassis either. So we played with cominations of springs to accomplish this like you have. Seems like you have already figured out that the more leaves you remove, the more it will flex (get longer when compresssed). We found that setting the perches at 49 - 1/2" ceneter to center (stock measurement) seems to work best when usin an "A" spring. 1937 spring has 48" perch centers and is about 6" lower from the start, if you are looking for lower ride height, but you need to take a bunch of leaves out to soften the ride enough to work with a light weight car.
For a spring over the Tardel book says to use a 7 leaf pack, and take the top three, cut them down to 12" and then place them underneath the pack. Apparently it lowers it 2" or something, and will soften the ride for a light car.
That's a great book! I tried this on mine, but it was not enough. Wound up removing some longer ones too. But it's a matter of ride prefernce.
If your spring is 42.5 long you need to make the distance between the mounts at least 46 inches, that is assuming that you are using standard 1-1/2 inch shackles. This will make the shackles set pretty much level when you install the spring and they should be at around 45 degrees with a load. This angle will give the best ride and also provide good lateral support and you will not need a panard rod. Rex
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