transverse spring in front of rear axle

[rollingthunder]

So. I used the ford axle brakets to set my axle back farther.my question is I can get my upper locating arms to clear the spring. However The lower ones will hit the spring when it flexes..so can I just use the upper arms because the axle brakets act like lower arms anyways??

 

[Torch]

looks.... I don't know... Not right?

the shackles aren't supposed to be at that angle
the axle brackets only hold the body up off the rear end... the rear radius rods are what take all the torque and keep your axle out of the guys grill who's following

I see the rear axle wobbling bad side to side going down the road, and problems with the shackles not working right, and the axle brackets getting flexed back and forth until they crack at the welds.
The upper arms are at a bad angle
the upper and lower arms if you drew a line through them looking from the side...those lines should meet.
If they meet ahead of the center of gravity the car will launch nose lite and throw too much weight to the rear. (You want only as much weight transfer to hookup the tires. excess weight transfer will consume energy and result in lower et's)
if they line up too far behind the center of gravity the car won't hook up as good as it ought to.

the lenth of the arms and the angle off the centerline of the car looking down will effect the way it handles in a turn and under acceleration and braking. Cars can have bump steer from poorly designed rear suspension and can have either too much over steer or understeer for the liking of the driver.
You don't always want a perfectly balanced chassis
The 2nd generation F-body has a design such that it over steers a little on deceleration allowing a more aggressive entry into a turn than strickly the front wheel traction would provide.
And it under steers a little on acceleration allowing the nose to slide out in balance with the smoking rear that is trying to slide out. this understeer under acceleration out of a turn allows the car to remain under control and not spin out.

 

[Torch]

cars that oversteer under hard acceleration feel squirrely and have a tendency to swing the ass end around coming out of a turn and spin out.

 

[Torch]

This is more how it should look


And your shackles should be vertical not horizontal but not perfectly vertical because they need to have interfering angles to keep the axle from swaying side to side while allowing the spring ends to spread apart and come together as the spring flexes up and down.

I'm not beating you up or picking on you when I say this but it looks like you don't fully understand how the components your working with function and haven't been able to work it out on paper or in your head before you got to hacking.
If I can offer some philosophical advice one hax to another...
I always try to plan out a hack every possible way it could be done in my head and on paper first then I hack after I'm 100% on how it's going to be. It's really expensive to do your modeling with the parts you will be building with.

Your hanger brackets also will need horizontal gusseting so they don't flex side to side.

I'd also mount the shocks at an angle to help stabilize the rear

 

[rollingthunder]

First off I would just like to say thank you for taking your time to photoshop those locating arms!! That's amazing.. ok where to begin.... my shackles actuallly hang at 45 degrees I'm jut mocking up one side and didn't have the spring attachhed properly to the other side..2nd I have gussets but didn't want to tack them untill I'm 100%.. 3rd if I place me locating arms where you have them and put a panhard bar in it should that add some stability? Thanks again that was amazing

 

[Blue Eyed Devil]

Your shackles should be at 45 degrees under load, so the way you have them now will not work. The shackles will bottom out when you load the suspension and your spring will not work. They should be near level when unloaded, so you need to move the brackets farther out on the axle housing.

 

[zzrodder]

It would be simpler to create two long arms similar to split bones and mount the spring to them - sort of like a 'truck arm' setup. Taper them in to the frame so you will have the necessary triangulation to keep the rearend centered. Then you wouldn't need the 4 link or a panhard bar, though it's best to have them bolt to brackets welded to the axle tubes rather than just welding the arms directly to the tubes - they need to flex a little or they will crack.

 

[Blue Eyed Devil]

It would be simpler to create two long arms similar to split bones and mount the spring to them - sort of like a 'truck arm' setup. Taper them in to the frame so you will have the necessary triangulation to keep the rearend centered. Then you wouldn't need the 4 link or a panhard bar, though it's best to have them bolt to brackets welded to the axle tubes rather than just welding the arms directly to the tubes - they need to flex a little or they will crack.

This was my suggestion on the other thread...

 

[Torch]

I think if you have the shackles correctly configured there would be no need for a panhard rod.

Parallel shackles on both sides of a spring create a glider swing like you sit on when your sipping a tea on the veranda. it will rock

If you look at a properly configured transverse front axle and suspension you can see by the orientation of of the shackles that the downward force of gravity on the car causes the frame to hang suspended in opposing forces. the 45 degree opposing angles allows the spring to move while keeping the axle centered.

Now just having the shackles at the 45 degree angle isn't enough..
You have to have the gravitational force pulling through the shackles not pushing through them for the shackles to work stable.

I would move the axle brackets in until the shackles were at the 45 degree angle (suspension loaded remember the spring gets longer the more weight is on it).

1) find out the length of the spring center of eye to eye with the chassis fully loaded

2)add the length of your loaded spring to the length of 2 shackles(left and right) this looks to me like how you figgured where you welded your axle brackets.

3)The axle brackets should weld on with the center of their eye halfway between the length of the loaded spring and the length of the loaded spring plus the length of the 2 shackles

4)all measurements center of eye to center of eye.

5)Instead of trying to eyeball a center to center measurement you can measure edge to edge as long as you measure the same edge for each of the 2 holes (left edge of hole to left edge OR right edge to right edge)