Shackle Angle Question

[Ziptie]

I have a 72 wag, SUA, 4" springs & lift shackles. My shackle angle is currently like diagram "A" (front spring, sitting in driveway). I think that if the shackle angle was like diagram "B", the springs would flex more.
Questions:
- Is this correct?
- What should the center to center offset be? (the ? in detail "B")
http://i303.photobucket.com/albums/nn138/Ziptie3/72%20Wag/Shackle0001.jpg

[Kenall]

I have a 72 wag, SUA, 4" springs & lift shackles. My shackle angle is currently like diagram "A" (front spring, sitting in driveway). I think that if the shackle angle was like diagram "B", the springs would flex more.
Questions:
- Is this correct?
- What should the center to center offset be?

that is correct.
with the shackle's bottom tilted forward (for front springs) the ride will be softer and the springs flex more. with the front shackle 'inline' between the 'eye' of the frame mount and the 'eye' of the spring. its like not having a suspension at all.

center to center offset??
you mean the distance from the center bolt to each of the springs bushing 'eye's?? if that is correct, they should be the same for pre74 wags. but since you have lift springs (dont no if they are store bought or built) i cannot say.

if you mean center to center offset as to the postion of the shackle bolt on the frame and the shackle bolt on the spring. that depends on your shackle. but when the suspension is at full drop. you want the shackle to point straight down, not backwards.

what you could do (short of buying a longer 'main' leaf for your spring pack) is to relocate the front shackle frame mount 2" to the rear.

[Ziptie]

thanks for the info. I will be moving the shackle mount on the frame.

[Dmntxn77]

Are they new springs?

[Ziptie]

I put the springs on in June on 08. BJ's 4"

[Dmntxn77]

They will take a while to relax some, but as they do, your shackle will start to take a better angle.

If you move your shackle mounts before the springs relax, you will probably end up having to move them back. Otherwise, your shackle will point straight out. I suspect that will take a while though.

I have had those same springs, and the straight up and down shackle is part of the reason that I sold the truck. I didnt have the patience to wait for the springs to soften up, and I couldnt stand to drive the dang thing. Of course, the dirt road I live down sucks REAL bad (ask Al) and the truck was my DD...

In retrospect, I kinda wish that I would have just moved the shackle mounts, then back again, but oh well, I like my new DD better than the J20 anyway... :huh:

[Chevelleguy]

Mine looks like your 'B' illustration. It took several years for my springs to break in completely. Try flexing it out A LOT before you move the mount.

I know mine are broken in now because the shackle will flip forward and stick against the frame on a good dip in the road. I had to weld a 2" long piece of 3/4" pipe on the frame to give the shackle something to bounce off of so it wouldn't rotate all the way up to the frame. Works good.

[Ziptie]

So, I need to make a mount that has different mounting points. So I can adjust the shackle angle as the springs brake in.

[junglecruiser2]

I had the same problem with the stock springs and a springover. Finally ended up with bds springs for a CJ. I also used the chevy shackles.

[Rhino Racer]

that is correct.
with the shackle's bottom tilted forward (for front springs) the ride will be softer and the springs flex more. with the front shackle 'inline' between the 'eye' of the frame mount and the 'eye' of the spring. its like not having a suspension at all.



Would you care to explain the reasoning for this? I'm about to set the position of my rear shackles for a pair of long travel leafpacks, although the shackles hang upside down so does the same principle apply?

[imiceman44]

Would you care to explain the reasoning for this? I'm about to set the position of my rear shackles for a pair of long travel leafpacks, although the shackles hang upside down so does the same principle apply?

When the shackle is inline with the end of the spring, what happens is that the spring compresses and wants to flatten out and it pushes against the shackle whic in this case is like a crutch, it will stand up to it and then flip either side, the worst case scenario is it will flip in and possibly do some damage to the spring, or flip out and you get some flex but it will be very stiff.
Just so you get the feel of it, hold a stick, and push down on it, and then push sideways and you will see the difference.
You want to make it easy for the spring to flatten out so it rides smooth.

[Rhino Racer]

When the shackle is inline with the end of the spring, what happens is that the spring compresses and wants to flatten out and it pushes against the shackle whic in this case is like a crutch, it will stand up to it and then flip either side, the worst case scenario is it will flip in and possibly do some damage to the spring, or flip out and you get some flex but it will be very stiff.
Just so you get the feel of it, hold a stick, and push down on it, and then push sideways and you will see the difference.
You want to make it easy for the spring to flatten out so it rides smooth.

Took a while for me to picture it but finally go it! Makes sense now, thanks.