Home built independent suspension?

[loren85022]

http://www.piratepathy.com/AZ_IX/reddog/slides/P1010115.html

I watched the entire screenshow. Definitely a proven suspension. Fun looking group.

 

[CYi5]

Anyone have any input on using small coil springs instead of air bags for the rear independent suspension? Looking at options for a lightweight off road trailer (<1000 lbs).

Sources for spring selection and weld on coil bucket mounts?
Type of shock for dampening spring? Oil? Gas?

 

[CYi5]

I'm guessing a decision between a progressive vs. linear coilover spring be trivial on a trailer that i wouldn't be riding in? Or is there a preference?

 

[jwiereng]

Adjusting for toe should be pretty simple if you added a threaded insert and a bushing with a threaded stud to the inboard side of the trailing arm. Picture of the bushing...

For camber I would have to make the outer trailing arm mounts slotted with a plate to lock in the camber adjustment such as ...

I forgot to show that on the larger bracket, the center bolt hole needs to be slotted. The red circle represents the OD of the bushings. The camber plate is attached to the larger bracket and locked into position with the two outer bolt holes (3/8") as well as the bushing's 9/16" bolt. This set up would be used on both the inner and outer sides of the outer trailing arm bushing.

Confused yet? There would be no gaurentees that this would allow you to get the alignment spot on, but it would help get it pretty close and compensate for any movement of the metal as I welded up the trailing arms.

What do you think?

I like your bracket design that allows some adjust-ability that won't easily get bumped out of spec.

After thinking about the mention on a slot in the larger bracket it became apparent to me that there should be a slot in the smaller bracket too. The slot should be perpendicular to the slot in the large bracket

The 3 bolt holes on the left side of the smaller bracket should not be arranged perfectly vertical as it appears in the drawing but they should be in a arc.

I'll draw up my thoughts if the explanation is not clear

 

[ScottReb]

Resurrecting and old thread. But is there any reason not to use 2 of the adjustable bushings? On both inboard and outboard trailing arms. Ballistic Fab has forged one and a weld in bung that goes into 2x2 x 1/4 tube with a 1 1/4 bolt. http://www.ballisticfabrication.com/Forged-Poly-Bushing-175-OD_p_1944.html or the welded up version noted. Seems to me that would be the easiest and quickest non fab way to get fully adjustable.

 

[ScottReb]

I answered my own question about using them on both in and outside. They would still only add length to the trailing arm thereby changing toe in only. You would still need a way to correct camber. Here is nice video of how one Aussie manufacturer's system works. https://www.youtube.com/watch?v=Sqltj6cgUis

 

[Nd4SpdSe]

How about using some stock or aftermarket control arms from a vehicle, and just making up the mounts? Less to warp?

 

[97kurt]

Digging this one back up.

About to start building my suspension arms next week. Was wondering how everyones were holding up and also what kind of shocks people are running as I need to order a set pretty quickly?

 

[Gootjr]

Independent help

Not sure if it helps but I'm just finishing up my trailer and I did independent myself. I ran a straight tube tacked in place to build and then cut the center out.

 

[89YJ]

I think you also have to understand the accuracy of chassis on vehicles.

on the average rangerover chassis they can easily be 3/8" to 1/2" out over the length......especially diagonals...

The rear wheels have no real adjustment because its not important....the front wheels yes as they steer the vehicle.

On a trailer it would make little or no diference if the wheels were miss aligned by 3/8" or more.

Tire wear at that amount would be negligable if not completely unseen....

especially when you consider the amount of miles you'd complete....

I started with a shop bought frame and it was easily 1/2" out on the diagonals
and still tracked fine.

I'm working to about 1/8" tolerance on the frame of my new one.....

The upper body was built matched to the frame.

Movement during welding is normal...and way worse on small wall tubing, the heavier wall you get the less movement you'll have.

And also small tack welds done first....beat the item into shape and then final weld the construction is an easy 'garage method' of getting less movement.

If you just completly weld one side....by the time you turn it over.....its changed shape...wether you clamped it down or not.

Front suspensions and alignment is highly important....and the manufacturers know they can't weld the parts to a sufficient tolarance...hence the in built adjustment in the design.

I am new here but am interested in the topic. I am designing a build right now and am researching independent suspension otions. Timbren might be nice but the price is not. I have over 25 years fab experience so the heat distorsion problem I can handle. What I am not finding much info on is coil spring availability. Leaf springs, everywhere. For right now I am doing a Sawtooth build to go behind a Jeep so nothing too heavy. I am thinking springs under 3500lbs but over 1500. Any suggestions would be appreciated. Mike