Shackle geometry - Math Question -
#1
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Shackle geometry - Math Question -
I have had a Zone off road 3.5" lift, full leaf pack, on for over a month now, and the shackle angle is actually worse than 90 - I am looking at putting on a shackle relocation bracket, but want to keep the lift hight and pinion angle close to exactly the same. I wanted to see if you guys thought my math and thinking are correct in figuring out the length of the new shackle I should get with a no lift relocation bracket, or hight adding relocation braket. - so the stock shackle is 3" - so assuming at best a 90 degree angle in thinking of a 45, 45, 90 triangle, the length of the new shackle should be 3 *√2 or 4.24" correct? or a shackle relocation bracket that adds at least 1 1/4" of lift and stock shackle to stay at the same hight. My shackle is actually pointing slightly forward, so most likely closer to 4.5"? Is this correct?
#2
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Year: 2000
Model: Cherokee
Engine: I 4.0
I don't know if your math is correct or not. But what I do know is that the amount of added lift a relocation bracket will give you depends on your shackle angle after installing the bracket and obviously how low of profile the bracket is. So, seeing how your shackle angle is currently way off, if you were to install relocation brackets and improve your angles you may not add more then a 0.5 inches of lift to your rear. Again, different brackets may alter the numbers a bit depending on design. If you want to add lift from there, just get longer shackles. As for pinion angle, properly set up rear suspensions have less need of shims. So I would work towards optimal shackle and leaf geometry then worry about pinion angle after that, if you even need to.
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Year: 1994
Model: Cherokee
Engine: 4.0
First math problem I see is that I don't think you are accounting for the difference between extra height at the shackle end and lift at the axle.
The relocation bracket that adds "at least 1.25" of lift" at the axle is adding at least 2.5" height at the shackle where you are doing your calculations.
I just installed a low profile relocation bracket with stock shackles. I had angles similar to yours. I'll take some measurement and post photo tonight.
The relocation bracket that adds "at least 1.25" of lift" at the axle is adding at least 2.5" height at the shackle where you are doing your calculations.
I just installed a low profile relocation bracket with stock shackles. I had angles similar to yours. I'll take some measurement and post photo tonight.
#5
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Year: 1996
Model: Cherokee
Engine: 4.0L
FST No lift shackle relocation bracket, RC 1-2" lift shackles set to first hole (1") placed on second hole closest to engine in relocators. RC 4.5" full pack. No lift added what so ever.
#6
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What I am thinking is the FST low profile shackle relocation kit, - so no lift from the relocation bracket, and then a 4.5" shackle. I was reading about the GM truck shackle that is exactly that long and would work on a Cherokee. If my math was correct, this combination would give any Cherokee with a vertical shackle after a spring lift a 0 gain/ loss configuration when going to a shackle relocation config. For me my truck is completely level right now, as well as I already installed my SYE and torched off and re-welded my spring perches so axle yoke is in a direct line with my driveshaft. I don't want to mess any of that up. Does this sound right?
Also, in looking at the shackle relocation brackets, It looks like they all bolt in one way or another into the rear frame bolt holes, - What do the people with tow hitches and gas tank skid plates do? is it just a stacking one on top of the other exercise?
Also, in looking at the shackle relocation brackets, It looks like they all bolt in one way or another into the rear frame bolt holes, - What do the people with tow hitches and gas tank skid plates do? is it just a stacking one on top of the other exercise?
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Year: 2000
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1) yes sounds right
2) how the relocation brackets were made they are against the frame, for the bolts to line up.
Also a good time to replace any hardware they sell nut strips with the brackets at a good price.
2) how the relocation brackets were made they are against the frame, for the bolts to line up.
Also a good time to replace any hardware they sell nut strips with the brackets at a good price.
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#8
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Year: 1996
Model: Cherokee
Engine: 4.0L
What I am thinking is the FST low profile shackle relocation kit, - so no lift from the relocation bracket, and then a 4.5" shackle. I was reading about the GM truck shackle that is exactly that long and would work on a Cherokee. If my math was correct, this combination would give any Cherokee with a vertical shackle after a spring lift a 0 gain/ loss configuration when going to a shackle relocation config. For me my truck is completely level right now, as well as I already installed my SYE and torched off and re-welded my spring perches so axle yoke is in a direct line with my driveshaft. I don't want to mess any of that up. Does this sound right?
Also, in looking at the shackle relocation brackets, It looks like they all bolt in one way or another into the rear frame bolt holes, - What do the people with tow hitches and gas tank skid plates do? is it just a stacking one on top of the other exercise?
Also, in looking at the shackle relocation brackets, It looks like they all bolt in one way or another into the rear frame bolt holes, - What do the people with tow hitches and gas tank skid plates do? is it just a stacking one on top of the other exercise?
Yes, definitely order the nutstrips with it!! As far as the hitch/bumper/skid goes, I know FST works with most, I have a aftermarket bumper, I just picked up longer bolts. But it goes FRAME>RELOCATOR>BUMPER> So on. Relocator always sandwiched to frame.
#11
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Year: 1994
Model: Cherokee
Engine: 4.0
My shackles are binding. There are some photo on my build log. It can probably be made to work but I'm not sure it will work well.
I'm considering the Superior 13-4100 (Chevy lowering) shackles.
#12
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Year: 1996
Model: Cherokee
Engine: 4.0L
So far, I'm having issues using the stock shackles with the low profile relocation bracket. I'm not seeing any loss of lift though.
My shackles are binding. There are some photo on my build log. It can probably be made to work but I'm not sure it will work well.
I'm considering the Superior 13-4100 (Chevy lowering) shackles.
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Year: 1994
Model: Cherokee
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I made my way to Autozone, tape measure in hand, and took a look at the 13-4100 shackles. Minimum length is 6.25" center to center with another hole at around 7.5". They look sturdy and I think they are a deal if you want an inch or two of extra lift.
I don't want any extra lift (or no more than I can avoid) and I feared a bad shackle angle when used with my too short RC springs so I passed.
I don't want any extra lift (or no more than I can avoid) and I feared a bad shackle angle when used with my too short RC springs so I passed.