Shackle angle

[Aisin]

Doing some mock up on my truck. I think I have it figured out. Any input for my dumbass? Move it or leave it alone?

 

[Yotota]

Run it IMO.

 

[Aisin]

Run it IMO.

That’s what I’m thinking. With the shackle hanger just slightly forward the leaf eye will bottom out against the frame. In it’s current location there is just over an inch of clearance between the leaf eye and bottom of the frame with the axle into the bumpstop.

 

[Yotota]

Just to confirm - is this a trail wheeler/crawler?

For a go-fast rig, others will have better input...

 

[u2slow]

To me it seems like the shackle lays too flat. It'll want to stretch out a curved leaf spring.

That said, I'm not a Yota guy, and my dodge springs are quite flat and sturdy to begin with.

 

[Aisin]

Just to confirm - is this a trail wheeler/crawler?

For a go-fast rig, others will have better input...

Just a trail rig.

To me it seems like the shackle lays too flat. It'll want to stretch out a curved leaf spring.

That said, I'm not a Yota guy, and my dodge springs are quite flat and sturdy to begin with.

That’s as flat as the leaf is getting. It’s slightly inverted.

 

[u2slow]

That’s as flat as the leaf is getting. It’s slightly inverted.

What I mean is if your leafs are soft in the first place, that shackle angle will push you to bottoming out in a hurry. It's that side-effect of the shackle angle affecting your spring rate.

 

[bdkw1]

That is super close to binding. What's it look like dropped out?

 

[Aisin]

What I mean is if your leafs are soft in the first place, that shackle angle will push you to bottoming out in a hurry. It's that side-effect of the shackle angle affecting your spring rate.

This pack has 9 leaves I believe. I break it down to the main leaf to get rid of all the variables.

 

[Aisin]

That is super close to binding. What's it look like dropped out?

With my fat ass (173 pounds) standing on the main leaf the angle is near vertical.

 

[bdkw1]

With my fat ass (173 pounds) standing on the main leaf the angle is near vertical.

Ok, then I would move the mount back a little the shackle away from being flat at bump. You need a little wiggle room for flex and stretch. Putting the springs into compression length wise is a good way to bend them.

 

[Clb]

Didja add a block equal to the missing leaves???

 

[bdkw1]

Didja add a block equal to the missing leaves???

Why? Spring under........ Unless you are planning on stacking all the leaves on top of the main one

 

[Clb]

Shiiiit
Yea 2" screen issues.
I still wanna see loaded, full stack shackle angle before committing to that full stuff minus compression...

 

[GRM]

Run a longer shackle above or through the frame. Its that torn down, so it will be easier to install now.

 

[bdkw1]

Run a longer shackle above or through the frame. Its that torn down, so it will be easier to install now.

An excellent option if there isn't a cross member above it. Then make some mounts for delrin slider plate to keep the long shackles from beating up the bushings.

 

[Aisin]

Currently fucking around in the garage. With the axle into the bump stops there is 1.25” of clearance between the leaf spring eye and the bottom of the frame.

 

[rockota]

i see no value in running a shackle at such an extreme angle, even fully compressed.

what's the angle at projected droop and ride height?

 

[Aisin]

i see no value in running a shackle at such an extreme angle, even fully compressed.

what's the angle at projected droop and ride height?

These are not final. Just tacked to the frame. With my 173 pound ass standing on the spindle the shackle angle is near vertical. Not sure about ride height. I still need to buy the correct size bolts for center pins.

 

[GRM]

An excellent option if there isn't a cross member above it.

I just ran out to my ‘86 to compare… why is your spring so far forward? Or are you running short (48”) leaf springs? I would have assumed longer since it appears your running spring under, and with that short of leaf, you’ll be far too assuming it has a solid front axle.

 

[YotaAtieToo]

I think it's too flat. You're asking for a stuck shackle once the bushings break in a bit.

 

[rattlewagon]

Looks too flat. What your goal for ride height shackle angle? Is the bumpstop going to compress more with real weight on it?

 

[Aisin]

Looks too flat. What your goal for ride height shackle angle? Is the bumpstop going to compress more with real weight on it?

It will definitely compress with more weight on it. I’m thinking about spacing the bump stops down to keep the spring from going negative.

 

[Aisin]

Shackle hanger definitely needs moved back. I finally got bolts to put my leaf packs together.

 

[bdkw1]

Yeah, move it back till its vertical or tilted forward a little.

Don't space the bumps, going a little negative won't hurt anything.

 

[YotaAtieToo]

Use the formula

Spring length minus shackle length plus 1"

Or move it back about 1/2" from where it was and call it good.

 

[Aisin]

Use the formula

Spring length minus shackle length plus 1"

Or move it back about 1/2" from where it was and call it good.

I was literally just out there 2 minutes ago. I was thinking a half inch would be good.

 

[wagfabulous]

Your shackle should be near its longest point when your spring is at its max length (flatest) or most compressed . In reality as long as you run out of spring before you run out of shackle youll be fine. The rest is ride height preference.