Caster Correction Question

[LFD2037]

I installed an OME 850/860 lift(heavy front/medium rear 2.5") & I need caster correction. I was under the impression a 2.5* bushing corrected the caster by 2.5*, 3* corrected 3* of caster, etc. BUT I read a thread that said a 2.5* caster kit gave you a total positive caster of 2.5*, a 3* gave you a 3* caster, etc. Which is true? Also, anyone who did the caster washer mod regret it? It seems extremely simple & effective w/a really low cost. Thanks!

 

[Pin_Head]

I measured the offset of the hole of the OME yellow bushings and calculated the angle change. My recollection is that each bushing is more like 2.5 degrees. Each inch of lift changes the caster 1.7 degrees, so a 2.5 inch lift would need about 4.25 degrees of caster correction. With two 2.5 degree bushings you get approximately 5 degrees of caster change. Nothing wrong with the washer method as it accomplishes the same thing and you get to keep the stock rubber bushings, which is a plus. As a negative, you have to drill or grind the holes to elongate them and you need to be able to weld the washer in place properly.

 

[LFD2037]

I understand what your saying. On the other hand there is a lot of people who say they had a -1* caster, install OME 2.5* bushing & end up @ only +2* caster. If the OME 2.5* bushing give 5* caster correction then how can that be?

 

[ironhippy]

I understand what your saying. On the other hand there is a lot of people who say they had a -1* caster, install OME 2.5* bushing & end up @ only +2* caster. If the OME 2.5* bushing give 5* caster correction then how can that be?

this was my experience. I went back to OEM bushings and did the washer method.

 

[Pin_Head]

If the OME 2.5* bushing give 5* caster correction then how can that be?

Maybe they weren't installed correctly. If you don't get them oriented correctly, you do not get the full caster correction.

 

[LandCruisinMy93]

I installed an OME 850/860 lift(heavy front/medium rear 2.5") & I need caster correction. I was under the impression a 2.5* bushing corrected the caster by 2.5*, 3* corrected 3* of caster, etc. BUT I read a thread that said a 2.5* caster kit gave you a total positive caster of 2.5*, a 3* gave you a 3* caster, etc. Which is true? Also, anyone who did the caster washer mod regret it? It seems extremely simple & effective w/a really low cost. Thanks!

sounds like you need to buy some 3* bushing and some 3* caster correction plates from someone willing to sell unused still in the package stuff that they didn't end up using for cheap. Just saying...I might know a guy......Me, that guy is me.

 

[LFD2037]

I've decided to do the washer mod. Now, w/an OME 2.5" lift, do I need to do just the front holes on each bracket OR do both front & rear on each bracket?????
http://www.lcool.org/technical/80_series/caster_mods.html

 

[Pin_Head]

Slotting the front by 14 mm will give 4.3 degrees of caster correction, which should be perfect for a 2.5 degree lift. Similarly, the CC bushings are offset by approximately 7 mm, so each bush is approximately 2.15 degrees and two of them should give a total of 4.3 degrees when installed correctly.

You can calculate the angle easily. Divide the distance the front bolt moves by the distance between the front and rear bolts (~185mm). Then using the trig functions on a calculator, take the inverse sine of the result to get the angle.

example: 14/185 = .0756
invsine(.0765) = 4.34 degrees.

 

[LFD2037]

Dude that's way over my head!!!!!! Thanks for the info.(14mm move down causes +4.3* caster change).

 

[Pin_Head]

Dude that's way over my head!!!!!! .

What? You can't use a calculator to divide two numbers and then find the invsin button? You need to practice.

 

[superstan26]

What? You can't use a calculator to divide two numbers and then find the invsin button? You need to practice.

I don't even know what the invsin button is, guess I'd better practice too. If I didn't have one on my phone I probably wouldn't even own a calculator.

 

[LFD2037]

I don't even know what the invsin button is, guess I'd better practice too. If I didn't have one on my phone I probably wouldn't even own a calculator.

That's what I'm sayin'! I can divide 2 numbers, yes, but haven't a clue what an invsin button is either.

 

[bmac1996acc]

Inverse Sine

 

[Pin_Head]

The invsin button is also shown as sin-1 or arcsin (all different notations for the same function) and is one of the 6 trigonometry functions on scientific calculators. The main 3 are sine, cosine and tangent and their inverses. Most calculator apps have a scientific mode that shows these additional buttons. You can calculate the exact angle change if you measure the distances involved. Beats guessing every time.

 

[concretejungle]

I have a set of oem arms with slee blue cc bushings pressed in using landtanks template for sale. I ended up moving up to the 4 inch lift and went with slee's arms.

Pm me if interested.

 

[LandCruisinMy93]

I installed an OME 850/860 lift(heavy front/medium rear 2.5") & I need caster correction. I was under the impression a 2.5* bushing corrected the caster by 2.5*, 3* corrected 3* of caster, etc. BUT I read a thread that said a 2.5* caster kit gave you a total positive caster of 2.5*, a 3* gave you a 3* caster, etc. Which is true? Also, anyone who did the caster washer mod regret it? It seems extremely simple & effective w/a really low cost. Thanks!

Im not here to sell you on My religion my Friend, You do not seek Forum assistance, your life is lacking because You Lack the Guidance of CHRISTO in your life.

 

[superstan26]

Im not here to sell you on My religion my Friend,

your life is lacking because You Lack the Guidance of CHRISTO in your life.

Not sure what generated this statement, but it sounds like gospel to me.

 

[TheBigBoy]

I've decided to do the washer mod. Now, w/an OME 2.5" lift, do I need to do just the front holes on each bracket OR do both front & rear on each bracket?????
http://www.lcool.org/technical/80_series/caster_mods.html

That info on lcool is not right. 14mm does not rotate caster by 2 degrees.

 

[LFD2037]

That info on lcool is not right. 14mm does not rotate caster by 2 degrees.

So it's really 4.3 degree rotation & not 2 degrees, is that what your saying?

 

[TheBigBoy]

That's the quick easy math behind it to dispel the theory 14mm = 2 degrees of caster rotation. But it's not all the math. It will be slightly less than that.