trailing arm question?

[Rev Tex Devlle]

ok iam planning on cutting the springs in half, and using them like trailing arm,, i should say i will cut one in half and use it for the arms, and the other i will use for the buggy spring,, i have z'd the frame and this will lower me to 10 inches of ground clearance , at the bottom of the frame,, also the springs use to ride on top of the axle, i am going to move them under and build a saddle for them,,, i have meausered the springs, they are the same distance from eye to eye and the curve of the spring is the same,,, so will this work,, i am not runjning no big motor just a stock flatty with a f3 trans,, the rear end is high geared,, i was just wondering about, the sway facture,, my skill are good i have been welding since high school,, {trade school} and i currently build car trailers for a living,, have a good wire welder and stick also.. not worriedwith the welding,, just wanted to know what yall think about ,, leaf springs as traileing arms,, i saw it once on a rock climber jeep,, anyway advice please,, yes i know i could build trailing arms outr of tubing, but this is a real low buget build,, and the boss wont spare the tubing

 

[donsrods]

While anything is possible, I have to admit I am not crazy about this idea. Yes, you could use the half spring as the LOWER arm, but I would use a traditional arm for the top. Lots of cars have been built this way, some from the factory. One example is the old bug eyed Sprites and MG midgets. They used a quarter eliptic spring on the bottom and a rectangular top bar as a locator.

Posies also told my Son that it was ok to use their quarter eliptic spring setup on the bottom as I described above, with a regular single bar on top, but we didn't want to chance that, so we used a four bar setup with the spring still on the bottom.

The problem as I see it with two springs only per side is that the axle would be able to move around too much. I know you cite low HP, but just going down the road over bumps and all puts a tremendous strain on these components. I think two springs would have too much monkey motion.

Here is the setup we ended up with.

Don

 

[Bonehead]

I agree with Don, seems like wheel hop would be a given. I am big into rock crawling, and have not seen this set up on anything. If it worked well I think more people would have it.

 

[Rev Tex Devlle]

well i was looking at the old model a set up,, radius rod and a buggy spring,, was trying to do the same thing using the half springs as the radius rods,, i had planed on a pan hard bar,, was just wondering ,, would there be that much difference between the springs , and radius rods, ,, i realize that the springs would have maybe more spring to them , but was hoping maybe with the panhard bar,and the huge spring, across the top would make up for iyt,, any ways just a idea,, was thinking maybe a sway bar, i have added in the linkage

 

[bob w]

In my opinion, the only way to use half springs is to mount them as if they were ladder bars. The thick end would have to be attached to the rear axle the same way a normal leaf spring would be attached. The spring eye end connected to the frame. The spring would have to be so stiff as to make it no longer "springy". With all that said, you can make a ladder bar, or truck arm out of $10 worth of metal.

 

[Rev Tex Devlle]

ok look at this here what i had in mind ,

 

[Rev Tex Devlle]

this what i had in mind for the front

 

[DirtWorshiper]

Quarter eliptic springs are not just regular springs cut in half, they are actually designed and manufactured that way. I have seen people do it and it will work, but it is not recommended as the spring or springs may fail from being modified and used in a manner they were not designed for.

 

[boaski]

You also need to remember that most springs made to run parallel with the length of the frame are not symmetrical. When you cut them in half you will not end up with an identical pair.

I like the thought of doing things a little different but if it were me I would use 1/4 elliptical springs that were very stiff, as in no flex, for the trailing arms. You have the potential for a whole lot of uncontrolled movement with all of those springs (the way you have it drawn up).

That's just my personal opinion.

 

[Bonehead]

Great drawing.... (had to say something positive), (Kidding)

I like the front with a set of radius rods, and a panhard bar to locate the axle. I think it will ride pretty stiff with one spring arched up and the other down, but it will still move.

The back really needs a more positive way to locate the axle, in my opinion. I do like the idea, and it's really cool to do something different. But when the lower spring flattens out it gets longer, and pushes the axle back, then the spring tries to recover, and axle wrap is pushing the spring down. I know you aren't going to be super high horse power, but the weight of the vehicle will multiply the down force. Anyway, axle wrap will be trying to arch the spring. I see wheel hop as being the end result.

 

[Bonehead]

How about this?

 

[Rev Tex Devlle]

ok i cut the springs and did a mock up, didnt like it, so i did some changes,, i think i like better... it also looked better , more stable

 

[J88]

I have used this set up before.I have always just cut the back half of the leaf springs off right behind the rearend. Then used coilovers or motorcycle shocks , but I think a transverse spring will work. I'm going to build a T from a 72 Ford cab using this same setup.

 

[Rev Tex Devlle]

i thought about motorcycle shocks, but didnt figure they would handle the weight but maybe two set would,,, how did the bike shocks work for you?

 

[J88]

I have used motorcycle shocks several times . The 36 I have right now has a set of shocks from a 79 FLH. It has a mustang rear with a trianglated 4 link. My car weighs 2500 and the shocks are actually a little too stiff . A set from a 70's or 80's jap bike are easy to find and won't cost a lot.I don't know how much your car weighs , but the half springs and motorcycle shocks have always worked for me.

 

[Rev Tex Devlle]

wel being a harley mechanic by trade i was thinking about flh shocks with the air ride system,, but got somewthing different now, however the next truck i build is going to be different from this one, i am going to build my frame,, but i think i will use bike shocks,, a freind gave me some control arms with coils springs ,, so i used them,, but i still think i will use bike shocks, tostop the axle from traveling down and the springs poppin out, the 4 link system is what i will use next with bike shocks, the next truk will be completely different, i have learned alot on this build,,