Front shackles need to be moved?

Arched lift springs lengthen when they compress, unlike the stock flat springs which pull in for both compression and extension. Therefore, the static height eye-to-eye measurement is shorter for lift springs (the spring eye end of the shackle is forward of the frame mount) so that they do not lengthen and HIT the frame.

In order to deal with this there are a couple of common solutions.

1) Ignore it and just hook it up. It still works mostly ok but limits axle movement and articulation.

2) Get springs with more lift than you need and remove a leaf or two. This causes them to sag a bit and results in a better shackle angle plus softer rates. However, you will need longer shackles to prevent hitting the frame and this will affect your caster. Note that this may affect spring life and warranty. Same effect can be achieved by experimenting with hybrid spring packs (as Donovan had great success with) or ordering custom spring packs. I believe Stephen Watson of ORD has a very nice spec for custom springs that solve this problem. Greg72 has a pair IIRC.

3) Relocate the upper shackle mount forward and add longer shackles as in 2 above. This will effectively reduce spring rate and allow much more movement. It will also not void your warranty. However, it is much more work and you should make sure you know what your doing before starting modifications to critical suspension and steering components.

I’m currently planning on implementing #3.

 

I kinda lumped your #4 into my #2. /forums/images/icons/laugh.gif

Yes, it moves up a little, but, if you put the casting right down on the lip of the frame channel (rotating it just a little from the stock orientation), it's not that much. I estimate that my shackles will be no more than 7" long to get what I want.

 

Good idea, hadn't even considered that. I'll look next J/Y trip...