Topic: Lifting the front and using longer shackles

[Eschenfeldt]

So I bought a old man emu 2 inch lift kit and it sits a bit high in the rear do you think I can use longer shackles upfront to fix the issue? Will this cause pinion angle problems? I could Probably also use a longer drop hanger but that requires a lot of cutting and welding so if I can avoid it and just use a longer shackle I would prefer that. If anybody has any thoughts it would be much appreciate it thanks.

[Wainiha]

i have a 2012 IFS so...

But my thought would be that if engine/trans and xcase moves up and axles stay at the same height then pinion angle would change.  I'm sure someone here knows more than me.  That's why I ask all the time.

[RUGER]

a little bit longer is ok but I think running like a foot long shackle would be to much. keep in mind the springs will settle down a bit after they get broken in.
im sure someone will chime in and give you the answer yer looking fer.

RUGER

[Snowtoy]

Chances are, the rear springs will settle in a few month's or so, so you should wait to address the difference in height.

[OVRAROK]

Put some weight in the bed, drive around for awhile. Should help rear springs settle.. you could always pull a leaf in each spring pack too...

[Gnarly4X]

So I bought a old man emu 2 inch lift kit and it sits a bit high in the rear do you think I can use longer shackles upfront to fix the issue? Will this cause pinion angle problems? I could Probably also use a longer drop hanger but that requires a lot of cutting and welding so if I can avoid it and just use a longer shackle I would prefer that. If anybody has any thoughts it would be much appreciate it thanks.

What is "a bit high.."??  1/2", 2", 4"??  All three of my Toy trucks have sat higher in the rear.  My current stock 1986 XtraCab sits 1" higher in the rear.

The rear springs are factory original, now about 34 years old.

I don't believe the pinion angles will be affected.

I would not fab new front shackles.

For my past 90% rock crawling having the rear slightly higher than the front was better for climbing obstacles.

High quality newly installed leaf springs will not "settle" very much at all - maybe a 1/4 to 1/2".  Over time they will start to sag, but it most likely will take more than several very active 4-wheeling years.


Gnarls.

[Eschenfeldt [OP]]

 Thanks for the feedback it’s been three months but I never have any weight in the rear so I guess I should get some  stress on those rear leaves my other question was does anybody know if I’ll be able to fit a high steer kit with only a 2 inch lift?

[Wainiha]

I read wrong. Pinion angle affected...I was thinking U joint angle.

Pinion not affected but U joints will be?

[Duffil]

pinion angle will be affected. the axle is in the center of an arc (the spring). you move one side of it down, it moves (rotates) the axle. So you affect not only the pinion angle, but by extension you affect U-joints, caster and camber..all of your steering geometry. How much it's all affected depends on how far you move the end of the spring. Keep in mind that a 1" longer shackle is roughly 0.5" lift. How much is too much? that depends on you.

[Gnarly4X]

Please explain how raising the rear end with a different set of leaf springs bolted to the same plated on the axle housing changes the angle of the pinion? 

Pinion angle is typically changed with wedges of different degrees, usually to get the 2 U-joints at the same angle.

If the shackles in the front are extended 1" how does it affect the angle of the pinion?

Lifting the rear end with a different spring pack will affect the centerline angle of the transmission output shaft.

But.. I'm relatively new to 4-wheel vehicles and 4-wheeling.

Gnarls.

[Willard]

Please explain how raising the rear end with a different set of leaf springs bolted to the same plated on the axle housing changes the angle of the pinion? 

Pinion angle is typically changed with wedges of different degrees, usually to get the 2 U-joints at the same angle.  **Unless the spring pin is perfectly centered in the arch of the spring or at least the same difference of the old springs the pinion angle will be affected**. Will also depend on how worn the springs are. If they are flat so is the perch.

If the shackles in the front are extended 1" how does it affect the angle of the pinion? **It more so raises the body and drivetrain included which will affect the overall driveshaft angle**

Lifting the rear end with a different spring pack will affect the centerline angle of the transmission output shaft.

But.. I'm relatively new to 4-wheel vehicles and 4-wheeling.

Gnarls.

[Gnarly4X]

Hi Williard,

I believe you are a fart smucker, and probably know more than I do about Toyota pickup suspensions, so I'm trying learn as I go.

Explain exactly the geometric and physical changes that can affect or change the angle of the pinion.

Old Emu is a very high quality manufacturer of the suspension parts.  They may be the only one of many leaf spring suppliers that actually fully skrag their leaf springs, so they won’t settle enough to be noticeable.

The arc of the bottom spring that sits on the housing pad is what *may* change the angle of the rear pinion.  For Old Emu springs, if it does rotate the axle housing it will be very slightly and would have to be measured with a highly accurate angle finder.. basically to have to add wedges to a 2” or 4” lift with a spring pack is very uncommon.

So… .can you please explain exactly how, by increasing the length of the front shackles, that will affect the front pinion angle?

In other words - WHAT FORCES act upon the axle housing that will cause it to rotate, which will change the angle of the pinion?

Thank you,

Gnarls.

[emsvitil]

The axle isn't centered on the leaf spring.    So more curve (lift) will rotate the axle when it's not in the center.

[Gnarly4X]

The axle isn't centered on the leaf spring.    So more curve (lift) will rotate the axle when it's not in the center.

Why would the bolt hole in the spring pack be different that a stock replacement??

And, yes.. if the bolt hole position is changed from stock, OEM replacement, it may rotate the axle housing if the arc of the bottom leaf is greater.

Gnarls.

[Gnarly4X]

The OP still has not stated how much of a lift he has measured with the Old Emu rear springs

Gnarls.

[Gnarly4X]

The OP still has not stated how much of a lift he has measured with the Old Emu rear springs

Gnarls.

   Raising the rear end of a truck so it looks like a cat in heat may or may not be desireable! 

Gnarls.

[Willard]

Hi Williard,

I believe you are a fart smucker, and probably know more than I do about Toyota pickup suspensions, so I'm trying learn as I go.

Explain exactly the geometric and physical changes that can affect or change the angle of the pinion.

Old Emu is a very high quality manufacturer of the suspension parts.  They may be the only one of many leaf spring suppliers that actually fully skrag their leaf springs, so they won’t settle enough to be noticeable.

The arc of the bottom spring that sits on the housing pad is what *may* change the angle of the rear pinion.  For Old Emu springs, if it does rotate the axle housing it will be very slightly and would have to be measured with a highly accurate angle finder.. basically to have to add wedges to a 2” or 4” lift with a spring pack is very uncommon.

So… .can you please explain exactly how, by increasing the length of the front shackles, that will affect the front pinion angle?

In other words - WHAT FORCES act upon the axle housing that will cause it to rotate, which will change the angle of the pinion?

Thank you,

Gnarls.

I didn’t say it changes the pinion angle. It will change the driveline angle due to the drivetrain being lifted and the u joint or double card an or whatever you have will have to make the difference in the angle. I guess if you installed a super long shackle it could change the pinion angle due to it physically forcing the housing to rotate, but a small shackle lift shouldn’t really change anything.
Think of the spring eyelets as a part of a circular rotation and you keep adding length the spring via a shackle it continues in a circular path which would change pinion angle.

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[Eschenfeldt [OP]]

The OP still has not stated how much of a lift he has measured with the Old Emu rear springs

Gnarls.

2 inches. And yeah pinion angle would be affected that’s why I was thinking of also doing an aftermarket hanger in the front that would even everything out but I’m gonna wait a little longer for the springs to settle  i’m just worried that at only 2 inches I may not be able to fit high steer??

Edit: sorry you said in the rear, the rear looks like it’s about 3 inches and the fronts 2 inches giving that ass up in the air look which I’m not into... I got the heavy duty springs (I don’t know why the 22r isn’t powerful enough for me to carry anything)  maybe I should pull the rears and take a leaf out but I’m not sure if that would even help?

[Gnarly4X]

I didn’t say it changes the pinion angle. It will change the driveline angle due to the drivetrain being lifted and the u joint or double card an or whatever you have will have to make the difference in the angle. I guess if you installed a super long shackle it could change the pinion angle due to it physically forcing the housing to rotate, but a small shackle lift shouldn’t really change anything.
Think of the spring eyelets as a part of a circular rotation and you keep adding length the spring via a shackle it continues in a circular path which would change pinion angle.

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I am not trying to be contentious or argumentative but I do try to be FACTUAL.

So …. When I raised my ‘85 shortbed with a different leaf spring pack in the front and the back and installed a longer shackles in the rear. As I remember it was about 3.5” to 4” lift.  The rear pinion angle DID NOT CHANGE after installing rear springs.  BUT because the lift changed the U-joint angles, I had a little drive shaft vibration – I NEEDED TO CHANGE THE PINION ANGLE.  So I added wedges under the bottom spring to make an adjustment which eliminated the vibrations caused by the out of sync angles of the front and rear U-joints. 

I have spoken to 5 manufacturers about their leaf springs, pinion angles, and U-joint angles.

You can do your own research.  If you call Charlie at Rocky Road Outfitters in Utah, who sells Old Emu suspension springs and kits, he will happily explain when and how the pinion angle changes.  He’s been around 4x4s for a long time and sells to popular 4-wheel drive vehicle owners who are modifying their suspensions.

If the arc of the bottom leaf that mounts to the housing pad is increased enough it can change the angle of the pinion, BUT the amount that it changes is not typically an issue for common non-radical lifts, but it should be a consideration because of potential U-joint angles becoming out of sync.

Gnarls.

[Gnarly4X]

2 inches. And yeah pinion angle would be affected that’s why I was thinking of also doing an aftermarket hanger in the front that would even everything out but I’m gonna wait a little longer for the springs to settle  i’m just worried that at only 2 inches I may not be able to fit high steer??

Edit: sorry you said in the rear, the rear looks like it’s about 3 inches and the fronts 2 inches giving that ass up in the air look which I’m not into... I got the heavy duty springs (I don’t know why the 22r isn’t powerful enough for me to carry anything)  maybe I should pull the rears and take a leaf out but I’m not sure if that would even help?

I not sure why you bought the heavy duty Old Emu springs?? Those heavy duty springs are not typically recommended for our trucks unless the use is going to be carrying a huge load!

And, yes removing a leaf most likely will lower the rear and fix your dilemma.

Gnarls.

[Eschenfeldt [OP]]

I not sure why you bought the heavy duty Old Emu springs?? Those heavy duty springs are not typically recommended for our trucks unless the use is going to be carrying a huge load!

And, yes removing a leaf most likely will lower the rear and fix your dilemma.

Gnarls.

Sweet gives me something todo this weekend. So how I was kind of envisioning the longer shackle thing is the front hanger is a pivot point and when you put a longer shackle on the rear of the spring it changes the angle of the spring itself which is connected to the perch which is connected to the axle which is connected to the diff and so I imagine that the diff angle would change but I could be conceptualizing this wrong or it could just be such a slight change that my angle finder doesn’t notice

[Willard]

I am not trying to be contentious or argumentative but I do try to be FACTUAL.

So …. When I raised my ‘85 shortbed with a different leaf spring pack in the front and the back and installed a longer shackles in the rear. As I remember it was about 3.5” to 4” lift.  The rear pinion angle DID NOT CHANGE after installing rear springs.  BUT because the lift changed the U-joint angles, I had a little drive shaft vibration – I NEEDED TO CHANGE THE PINION ANGLE.  So I added wedges under the bottom spring to make an adjustment which eliminated the vibrations caused by the out of sync angles of the front and rear U-joints. 

I have spoken to 5 manufacturers about their leaf springs, pinion angles, and U-joint angles.

You can do your own research.  If you call Charlie at Rocky Road Outfitters in Utah, who sells Old Emu suspension springs and kits, he will happily explain when and how the pinion angle changes.  He’s been around 4x4s for a long time and sells to popular 4-wheel drive vehicle owners who are modifying their suspensions.

If the arc of the bottom leaf that mounts to the housing pad is increased enough it can change the angle of the pinion, BUT the amount that it changes is not typically an issue for common non-radical lifts, but it should be a consideration because of potential U-joint angles becoming out of sync.

Gnarls.

Ok, I will make this as simple as i can. If you remove your shackles and drop down your diff housing to the floor your pinion will slowly rotate toward the ground or visa versa, therefore changing the angle of the pinion. Your suspension rotates in a circular pattern therefore changing centerlines of the pinion.


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[Willard]

Sweet gives me something todo this weekend. So how I was kind of envisioning the longer shackle thing is the front hanger is a pivot point and when you put a longer shackle on the rear of the spring it changes the angle of the spring itself which is connected to the perch which is connected to the axle which is connected to the diff and so I imagine that the diff angle would change but I could be conceptualizing this wrong or it could just be such a slight change that my angle finder doesn’t notice

This is correct. Only if the shackle is long enough to make the difference. I don’t know how long it would need to be to actually make the difference.


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[Gnarly4X]

Ok, I will make this as simple as i can.  Your suspension rotates in a circular pattern therefore changing centerlines of the pinion.


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"If you remove your shackles and drop down your diff housing to the floor your pinion will slowly rotate toward the ground or visa versa, therefore changing the angle of the pinion"....

This is not relative to the question!

If you do what say, please explain WHAT SPECIFIC FORCE is acting on the axle housing that rotates it?

Gnarls.

[Willard]

"If you remove your shackles and drop down your diff housing to the floor your pinion will slowly rotate toward the ground or visa versa, therefore changing the angle of the pinion"....

This is not relative to the question!

Gnarls.

Hahaha


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[Willard]

In a stupid sense it does. Leave the springs bolted to the front hanger and housing and remove the shackles and slowly lower the housing with an angle finder on pinion flange and the pinion angle will change during droop. If that’s not correct then I guess I’m wrong.


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[Gnarly4X]

In a stupid sense it does. Leave the springs bolted to the front hanger and housing and remove the shackles and slowly lower the housing with an angle finder on pinion flange and the pinion angle will change during droop. If that’s not correct then I guess I’m wrong.


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Again.... please explain what force is acting on the axle housing!!???

Gnarls.

[Willard]

Again.... please explain what force is acting on the axle!!???

Gnarls.

I dunno I guess it’s a combination of the drivetrain lifting and axle separation from the drivetrain?


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[Gnarly4X]

Hey Eschenfeldt.... Here's my suggestion...

Call Charlie at Rocky Road Outback at  their "Tech" number:  435.654.1149.

I'm jumping out of this discussion due to my need for time for important things, like where to place my sticky for my conceal carry!   



Gnarls.

[Willard]

And yeah pinion angle would be affected that’s why I was thinking of also doing an aftermarket hanger in the front.

This is exactly what is recommended from high angle and Tom woods to help correct pinion angles.


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