[together]

I see they make offset shackles for the back of the rear springs but what about the front of the rear spring mounts. It seems like if you moved the back over a 1 1/2' wouldn't you want to move the front mounts over the same amount ?

[BlackoutSteve]

I think the idea behind the offset shackles is not for fitting larger wheels, but giving the rear suspension more camber than stock during body roll and suspension travel.
That's why the leaf springs aren't parralel to the car's centerline in the first place.

[baz67]

Camber on a stick axle is determained by the housing end not the springs. However, the body will roll more with the springs moved inboard more due to the more leverage the sprung mass has over the unsprung mass.

Getting more to the jest of the question the offset shackles are to allow a wider rear tire by getting the rear of the spring out of the way. The reason you do not need to move the front of the springs over is that the springs look like this / \ as viewed from plan view. By moving the rear of the spring in they are more or less even.

Brian

[Everett#2390]

In using the offset shackles, you have to move the spring perches, also.

[400bird]

how do you move the spring perches on the axle?

[69cama]

You have to carefully cut them loose from the housing and reweld. A die grinder will do a fairly clean cut or you can cut them off and save the housing only and buy new perches.

[BlackoutSteve]

Hi Brian, I am searching everywhere without success for the info I have on camber with rear leafs.
Camber on a "stick" axle (I assume you mean solid axle) is impossible to set at the housing ends, as this would require bent axles and would also mean you could adjust toe in/out, which we can't.
I'll keep searching but I think you will find that the reason the factories have toed-in rear leafs springs is for camber during suspension movement.
I don't think they do it for fun!
I do see that many sell offset shackles for fitting wider tires but am sure of the fact that they alter the built-in camber of the leaf springs..

[400bird]

Originally Posted by BlackoutSteve

Hi Brian, I am searching everywhere without success for the info I have on camber with rear leafs.
Camber on a "stick" axle (I assume you mean solid axle) is impossible to set at the housing ends, as this would require bent axles and would also mean you could adjust toe in/out, which we can't.
I'll keep searching but I think you will find that the reason the factories have toed-in rear leafs springs is for camber during suspension movement.
I don't think they do it for fun!
I do see that many sell offset shackles for fitting wider tires but am sure of the fact that they alter the built-in camber of the leaf springs..

how will the springs being 1.5" more towards the middle of the car make the tires lean in our out more (change the camber)? where ever the springs are if the axle moves it will move to the same position, not like it can move the top of tire to more of an angle inwards

[BlackoutSteve]

To the best of my understanding, if both wheels were to move up (or down) the same amount, then no change in camber is possible. It is when one wheels moves more than the other in a cornering (body roll) or bump/rebound situation that a camber change is present.
Bump = negative camber and rebound = positive.
The design is intended for body roll and not bump/rebound.
It is something I had always wondered and then eventually found out, but now I can't seem to find that info again.

I now know that this detail is really irrellevant to this thread, although at first I didn't think so.

[69cama]

If both rear tires are planted on the road the body roll will occur but the camber of the rear tires can't change with a fixed end axle.

[400bird]

ya what he said

well the camber would change when cornering but only because the body is moving away from the car, and a movement of the leafs would not cause the body to be in a different spot from the car

wait, CAMBER IS NOT MEASURED IN RELATION TO THE CAR ONLY THE OTHER TIRES so there is no posible way for camber to change (unless your picking up one tire like going over a speed bump or something where the ground is uneven)

[baz67]

This is not directed at any one person. It is to just clarify some issues, but feel free to correct me if my memory lacks.

Camber, front or rear, is measured relative to a level ground plane. That way there is always a known point to go back to. If you measure to anything else, what says that that other point is in its correct location.

I need to check some referance books, but I believe the springs are toed in is for geometric reasons. I will look into that.

Brian

[400bird]

Originally Posted by baz67

This is not directed at any one person. It is to just clarify some issues, but feel free to correct me if my memory lacks.

Camber, front or rear, is measured relative to a level ground plane. That way there is always a known point to go back to. If you measure to anything else, what says that that other point is in its correct location.

I need to check some referance books, but I believe the springs are toed in is for geometric reasons. I will look into that.

Brian

ya i was thinking the center of all 4 wheels being parallel to the ground but your way makes it a little clearer

[BlackoutSteve]

Good points guys.. I am begining to rethink what I thought I knew..
Damn, I wish I could find that info. Perhaps it was for stability or some other geometric reason..
I'll keep digging!