What is the shortest front parallel springs anyone has run? Speedway has 26 1/8 for novas, only ones shorter I'm finding are for trailers that have too high a spring rate. Looking to put a straight axle in an ot car (52 jeep cj) and want to relocate the axle forward from stock position but still under frame and not way out front. Spring will need to be roughly 22 inches if axle is centered. Want to do parallel springs because this will be the easiest to set up. Haven't decided on motor yet, I know the final weight will effect what spring rate to use. Is this possible or am I going to have to do a single suicide sping/axle set up/ Thanks for any opinions and ideas.
IMO go with a single cross spring would be the best..Many choices of mounting the spring [above, in front, behind ] the axle and a multitude of spring choices...Radius rods not difficult to mount and steering poses no different issues..Again, IMO..
When i wanted a short spring I went to a boat trailer store. ordered what i wanted. had I thought it was to stiff, I could have removed a few leaves, I guess.
Here are some that are 25-1/4 eye to eye and rated at 2 K per pair http://www.northerntool.com/shop/tools/product_200365450_200365450 Hunting the trailer parts catalogs might find a pair that are rated around 1500 a pair though. Here just a tad longer than what you were thinking and 1500 lbs http://www.northerntool.com/shop/tools/product_200365445_200365445
http://www.sdtrucksprings.com/index...-XgI6Q&zenid=20989d7fc3d46c6bfd8d9fab9934db4b 1008 is also 1000# Some others http://www.sdtrucksprings.com/trailer-leaf-springs 168 is another, 700#
I have a pretty new set of '37 Chevrolet 1/2 ton springs with four leafs per pack, they measure 26 1/2" eye to eye. Send me a note if interested. I measured them around 325 lb spring rate per side. They held up my truck front just fine with 250 inline six. Could be a little heavy for your jeep. Joe
I run small trailer springs on the Henry J. We remove a leaf from the right side and put it in the left side. It has ran for several years now. I hit the guard rail last fall and then replaced them with the same ones. It worked for me.
Keep in mind load capacity isn't the same as spring rate. Trailer springs are advertised by load capacity, not spring rate. Drag-oriented cars generally want lower spring rates and lots of travel, to let the nose rise on launch but keep the front wheels on the ground. Try this spring rate calculator. A transverse leaf set-up with a Panhard bar will allow cross-steering with correct geometry i.e. no bump steer. But how about three-quarter elliptics? See (B) below:
Steering is a future question. The side steer box needs to be on the fixed side of the spring. But I wonder if cowl steering is used how much bump steer will you really get on a low crown spring. I had looked at this calculator http://www.suspensionmaxx.com/tech-support/leaf-spring-calculator/ The 750# spring was 570#/", the 500# was 290#/" and the 300# was 200#/". Speedway sells 400#/" springs.
At least you are doing it right by thinking it through before building. Most people just put something together that looks right then spends a lot of time and money trying to fix problems. Good luck with the project.
Why don't you extend the front frame rails? I've seen this done on many old CJs to accommodate longer springs, and/or move the axle forward for weight distribution or steering geometry. I think they look good when done right. I am working on a WWII Dodge WC59, which is built a lot like a Jeep-only bigger. I wanted longer springs, because the originals were so rough riding. I also stretched the frame 9" to accommodate a straight-eight, and the longer springs and moving the shackle to the back helped make up some of the stretch. On the military Dodges, those with winches had longer frame rails. I used winch frame rails to get the length I needed to mount longer front springs farther forward. On the civilian Dodge Power Wagons, they bolted an extension onto the frame instead of having an entirely different frame when a winch was added. There might be a similar trick you could use on the Jeep.
You can relocate the axle using stock length springs with the mounting point farther forward. Most cars with leaf springs at the back use this trick. The short stiff front part controls spring windup while the long flexible back part allows more suspension travel and a decent ride. Short springs limit suspension travel and result in a rough ride. There should be a spring shop in your area that can make any kind of springs you want. Since they work with leaf springs every day, why not ask them what kind of springs will work best? New springs for your Jeep, around $100 - $150 apiece.
Phill934, I am not sure what the spring rate is. The whole car weighs 2,800 lbs. They were for a small trailer. I chose them more on length than weight. I could add leaves if needed. Good luck with what with your project and make it safe as you can.
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