Shackle angle settling (1 Viewer)

[64Rotorhead]

Yes I know, many threads exist but most all I find are in regard to inches of spring settle, and not how that relates to the shackle angle. A loaded question I realize but just wondering if anyone had kept track of this during and after their build. Obviously it would vary with different springs, weights etc. But if enough folks have kept track and list their springs and overall set up, then I might be able to get a reasonable idea.

For example, if I wanted a 45º shackle angle in the rear, and I mock up with all weight on rig, plus whatever my normal weight of tools, spares, supplies etc., and I have a 35º angle, will it settle to 45º? I've just got the springs resting on the axle without U bolts, just some clamps, but I'm sure the U bolts will pull the springs a bit more flat as well.

 

[rkymtnflyfisher]

I didn't check my shackle while building my 40, I do know it settled a lot once I started getting towards the end. I may be able to find some pics of how my angles looked during the early part of my build and what it looks like now.

Of course I didn't do as cool of a build as yours!

 

[S4Cruiser]

When I did my build (SOA on 55 series springs) I removed the rivets on the rear hanger and drilled holes in the frame where I thought I wanted them. After one trip, I decided I wanted a steeper angle, so unbolt, measure and re-drill new holes (in the hanger this time). Once I am happy with where I want them, I'll burn them in.

 

[Downey]

When leaf springs are manufactured there are different features the manufacturer can put into the spring to make them have a longer life, i.e. not settle or fatigue so fast. Sooooo the answer to your question is (a) entirely dependent upon brand name of springs, and (b) how much and how often is the off road exposure/abuse???????

 

[snaggletto]

Don't worry about it. Take a guess and bolt/weld them in. They are easy enough to tweak later on.

 

[64Rotorhead]

I didn't check my shackle while building my 40, I do know it settled a lot once I started getting towards the end. I may be able to find some pics of how my angles looked during the early part of my build and what it looks like now.

Of course I didn't do as cool of a build as yours!

What's cool is of course relative to an individuals preferences

 

[64Rotorhead]

Don't worry about it. Take a guess and bolt/weld them in. They are easy enough to tweak later on.

Bolting might be the ticket. Cutting/grinding off the hangers after welding would be a pain, but doable of course, it's just metal

 

[snaggletto]

I replaced all rear frame gussets, and shackle mount plates and shackle hangers. I drilled an extra hole 1" forward in the hangers for better angle. They are bolted in with 3/8" grade 8 bolts. Would be very easy to do the same with stock parts. Just grind, air hammer, and or drill out the rivets.

 

[64Rotorhead]

When leaf springs are manufactured there are different features the manufacturer can put into the spring to make them have a longer life, i.e. not settle or fatigue so fast. Sooooo the answer to your question is (a) entirely dependent upon brand name of springs, and (b) how much and how often is the off road exposure/abuse???????

The rears in question are Alcans, FJ60 length but with the free arch relaxed about an inch. Off road will be it's place but with highways to get there. I'm waiting to get the axles bolted in with U bolts as I figure that will flatten them a bit as well.

 

[Downey]

Since we are no longer talking FJ40 rear springs in use on your rear end, then perhaps snaggletto's advice is reasonable.