rear spring shackle angle??

[toynizzy]

im getting ready to put my susp on my 85 xtra cab,whats the best shackle angle for the rear,some i have read say 30,35,45 and on and on.whats the best angle to get the most flex outta them?

[FIREBALL]

The more angle you have, the more droop you'll get. But, if you go too far then when you compress your springs the shackle will flop flat up on the frame rail. Also the more angle you have the more load sensitive it will be.
It's hard to get a lot of flex out of the rear, just because the springs are so far outboard compared to the front end and the load in the rear isn't always consistant. (camping vs day trip)
I usually set them up around 45deg or maybe a little steeper.

[CTENG in KS]

Try this...measure the length of the spring, eye to eye along the entire curve of the spring...then measure the length between your front spring mount and rear shakle mount eye to eye.  Subtract the frame measurement from the spring measurement...this, theoretically, would be your optimal shakle length...I've never actually measured, but it would allow for perfectly flat extension of the spring without loading it in tension or compression...

[blackdiamond]

whats the best shackle angle for the rear,some i have read say 30,35,45 and on and on.whats the best angle to get the most flex outta them?

From what I understand, the perfect shackle will be vertical at full extension and horizontal at full compression.

Try this...measure the length of the spring, eye to eye along the entire curve of the spring...then measure the length between your front spring mount and rear shakle mount eye to eye. Subtract the frame measurement from the spring measurement...this, theoretically, would be your optimal shakle length

CTENG has a great suggestion.  You should be able figure out the best place to mount your rear shackle mount based on the length of shackle you plan to run.  I would shoot for vertical at full extension (droop) and somewhere between horizontal and 45 degrees for full compression to avoid any contact issues.  I think that I have heard that 30-45 is a good ride height shackle angle.

[toynizzy]

well i have a 5 inch kit with 1 1/2 longer shackles,im going to have to move all my mounts and all that but was concerned about proper shackle angle,as ive heard ppl getting it wrong and not being happy with end result,spring bind and such

[skid]

From what I understand, the perfect shackle will be vertical at full extension and horizontal at full compression.

CTENG has a great suggestion. You should be able figure out the best place to mount your rear shackle mount based on the length of shackle you plan to run. I would shoot for vertical at full extension (droop) and somewhere between horizontal and 45 degrees for full compression to avoid any contact issues. I think that I have heard that 30-45 is a good ride height shackle angle.

Vertical on droop will most likely not work.  Mine goes past vertical and will lay flat on compression with a 6.5" shackle.   I'd say around a 30 degree anlge at ride hieght would work in most cases.

[MiniSimp]

I kinda like 45-50 deg. but I like my truck to have more droop than compression for a lower CG.