Correct Shackle angle?

SHINTON

SHINTON

Well-Known Member
Joined
Mar 17, 2005
Location
Triad area of NC
Ok...bringing up the shackle reversal again...and wanted to know what was the correct shackle angle "at rest"/flat on the floor?

Just a FYI, this is for my 90 YJ, I am looking at the kit below, and plan to drill a hole in the frame, and weld in a piece of pipe for my top bolt on the rear shackles. (Any tips on that is welcome...is there "normally" a bushing in there or just a grade 8 bolt "loose" in the sleeve/pipe?)

If I had to guess, the shackle needs to be able to move in EITHER direction (for stuffing vs drooping)...but prob MORE towards drooping? Thus, it would need to point slightly towards the front, say 11:00?

http://www.windrockoffroad.com/PART/MOR.8795-50/C/index.htm

Sam...NO freakn clue what he is talking about...Hinton
 
Sam, I just read an article (I'll have to look it up, don't remember where it was) but they were saying that the shackle reversal does no good off road...(they did say it was a dramatic improvement on the street). Their premis was something about the tire actually pushing back at the obstical in front of you and giving more tire pressure on the rock. Where as if you have the shackle reversal it will allow the tire to push away from the obstical (up to a point) and giving less tire pressure on the rock...I'll see if I can find it...read it in the last couple of day...
 
are you running a shackle reversal now? I'm not a YJ guy but I have heard bad things about it. Apparently they get stuck up against the frame, causes terrible axle wrap/wheel hop, and break U-joints when pinion goes way down and binds, from spring wrap. also under compression when the shackles are leaning the the left, the driveshaft hits the automatic trans pan/linkage.

that being said whats wrong with using double shackles and the appropriate length limiting straps?

(keep in mind I'm a leaf spring noob :rolleyes: )
 
Puma297 said:
are you running a shackle reversal now? I'm not a YJ guy but I have heard bad things about it. Apparently they get stuck up against the frame, causes terrible axle wrap/wheel hop, and break U-joints when pinion goes way down and binds, from spring wrap. also under compression when the shackles are leaning the the left, my driveshaft hits the automatic trans pan/linkage.

that being said whats wrong with using double shackles and the appropriate length limiting straps?

(keep in mind I'm a leaf spring noob :rolleyes: )
Click to expand...


porque?

double shackle w/ limiting straps?

did i miss something....

under compression when the shackles are leaning to the left, your driveshaft on a linked (apparently shackled rig) and coiled grand, hits your tranny pan.

what the hell is going on here???
 
refer to my earlier post...leaf spring noob, i know nothing.

aren't one of the disadvantages of double shackle setups excessive axle wrap and possibly too much droop? either problem being solved my a traction bar or limiting straps?
 
pheery said:
under compression when the shackles are leaning to the left, your driveshaft on a 4 linked (apparently shackled rig) and coiled grand, hits your tranny pan.
Click to expand...

and my DS is nowhere near the tranny pan under compression. :confused:
 
reread your post. you wrote, "my driveshaft"


and he never said anything about a double shackle setup, you did. a reverse shackle simply changes the fixed point to the front, and put the shackled end in the rear of the spring. read first...

and sam, i would say more than 11 o'clock. more like 45-50 degrees. also, i mounted mine through the frame as you are suggesting. in hindsite, i would mount it under the frame, and i will be changing mine in the near future.
 
I think this is a good angle.

316fb52a.jpg
 
pheery said:
and sam, i would say more than 11 o'clock. more like 45-50 degrees. also, i mounted mine through the frame as you are suggesting. in hindsite, i would mount it under the frame, and i will be changing mine in the near future.
Click to expand...

Hey Patrick...why? Better Pinion angle or?

Noah, where did you get your kit? (I like the little part on the rear for the shackle...I am sure someone wants uber bucks for it)

Sam
 
one, with the correct shackle angel, my pinion angle would be better. the other reason being that now i do not have a brace in my shackle, which allows more side to side movement than i would like.

but to do it from the start, it would be easier to set the shackle angle mounting it under the frame than drilling through the frame.

it can be done either way, but how i set mine up, if i braced the shackle, it would hit the frame when the tire is stuffed, so i can't do that. my cheapest and best option is to move the shackle under the frame.

spraypaintman's pic is what i want to do.
 
Sam..the way I've been doing it is this... flatten out the leaf completely. That's as long as the spring will ever get. Allow an extra 1/4"-3/8" for bushing play. When the spring is this length, set the shackle back so it's close to, but not at the point where it will just fold flat against the frame. That'll work! Whatever it winds up with at rest will be dependent of the arch of the spring.... but will allow for the most droop, and enough compression.

This is my rear leaf, has just a *bit* of arch in it.
rearshackleangle_jpg.jpg


This is the front during mock-up... this is a little too steep an angle: (and the hangar is backwards, too)
shackleangle_jpg.jpg


and causes this when you stuff the axle:
flatspring_jpg.jpg
 
Mine is from Poison Spyder Customs. It also outboards the spring mounts since my cj mounts were so narrow. It's also adjustable, it has multiple mounting holes for the rear hanger for different spring lengths and shackle angles. Maybe you could fab up your own rear mounts. I got the kit through DC4wd for a much lesser price than from PSC's website.

imga0058.jpg


imga0014.jpg


Hodie
 
spraypaintman. those look like some nice brackets! are you done with that thing or what.

Also about the shackle angle. I know rich hit the head on the nail.

tyler
 
Thing I liked about the PS setup was that they were tied together up front (especially for the CJ and the weaker front frame). It looks VERY much like the MORE kit up front, aside from being tied together. If you plan on going to longer springs, or anything fancy, I'd not bother with a kit, but make it yourself (if you're going standard ~130 might be worth your time). I was planning on using square/rectangular tubing scraps and outboarding, if I EVER get time to play with that.

Anyhow, there are SEVERAL threads on the outboarding issue in the Pirate Jeep forum, and much of it could carry over to your application.

This subject brings up other related issues (questions) for me when looking at going SRS.

1. I'm still wondering about longer/offset springs in that situation, it almost seems that you'd want to extend the front of the frame (yah I know approach angle takes a hit), and push the shackle mounts rearwards. I'm not sure how you really figure out the placement for this, because you got to take into account compression (where does the tire go), droop (where does the pinion angle go), and level use (where does the caster go)?

2. Buggy springs up front? Seems too gimmicky to me, but I've never met someone running them. M.O.R.E. sells them on their site (www.mountainoffroad.com/more it's their kit you're buying). Anyone ever run them (the springs up front, not the MORE kit specifically)?

3. I've only talked to folks who put a full-on kit kit on their CJs, and they generally liked it, but they were running lift springs (stiffer). Supposedly, there are reportedly dive issues in braking, but these guys didn't have them (again, RE 2" & 4" lift springs). I'm not sure how severe they'd be on a more softly sprung rig, and I'd be interested to know, as my rig will be used on and off road.
 
jeepeater2003 said:
spraypaintman. those look like some nice brackets! are you done with that thing or what.

Also about the shackle angle. I know rich hit the head on the nail.

tyler
Click to expand...

I'm gettin' there. Hopefully I'll get the high steer and fuel cell install knocked out next week.

Hodie
 
lomodyj said:
Sam, I just read an article (I'll have to look it up, don't remember where it was) but they were saying that the shackle reversal does no good off road...(they did say it was a dramatic improvement on the street). Their premis was something about the tire actually pushing back at the obstical in front of you and giving more tire pressure on the rock. Where as if you have the shackle reversal it will allow the tire to push away from the obstical (up to a point) and giving less tire pressure on the rock...I'll see if I can find it...read it in the last couple of day...
Click to expand...

Galen, thinking about the geometry, I have to somewhat dissagree with their statement on that. if you have the shackle in the front, the tire can be pushed further back with greater easy because teh shackle is gonna swing back. With the shackle in back and the axle anchored to the sring, the tire can only go back as far as teh spring will stretch back.. straight back.... I don't see that happening. If the shackle wants to lay back flat against the frame, so be it. it's not like it's gonna go all the way around.

now.. when teh shackle reversal can hurt you, is when backing up, then you can invert your shackle! but I've seen inverted shackles on the front too.

I still say it's 6 of one half dozen of the other, but the the reversal benefits on road, so why not do it!


Oh and Sam, you need to factor how flat/arched your springs are, and how much they will flatten out when you flex it. but a nice 45º should work in most cases.
 
I'll agree that a front shackle does press the tire into the rock, however, when the tire can't even GET to the rock because the 5" long shackle is hitting it, or the fixed end of the leaf springs just bent/broke because the axle can't move back, or the shackle inverted, you don't get much forward progress either... ;)

All of the above has happened to me (except the reverse shackle, seen that one more than once though)
 
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