Caster Correction for a 2.5" Lift (2 Viewers)

[LandCruiserPhil]

Which plates? Not all plates are created equal.

They are my design as they do not hang below the control arms. Cant remember the exact amount of correction but I do know they give the exact amount of caster as Metal Tech and Slee plates as the holes all layout the same.

Yes I would agree that not all plates are equal in caster correction or ease of installation.

 

[Pin_Head]

The change in caster angle is not linear with the increase in lift height. It is the inverse sine function of the lift divided by the control arm swing length at the point where the lift is measured. The first inch is 1.7 degrees, the next, 1.75, the next 1.83 and so on. It is the "invsin" key on your scientific calculator. Divide the lift height by the control arm length and then hit the invsin key. On some calculators it is called the arc sine function or arcsin.

 

[Kaninja]

Invsin is "Sin-1" correct?

Good to know, thanks for posting this.

 

[GW Nugget]

The change in caster angle is not linear with the increase in lift height. It is the inverse sine function of the lift divided by the control arm swing length at the point where the lift is measured. The first inch is 1.7 degrees, the next, 1.75, the next 1.83 and so on. It is the "invsin" key on your scientific calculator. Divide the lift height by the control arm length and then hit the invsin key. On some calculators it is called the arc sine function or arcsin.

Wow, that's awesome. Are you a engineer?

 

[Heckraiser]

For reference - My center of hub to underside of the flare measures 23" with a small amount of front to rear rake and my caster is at 4° using plates.

Is your front driveshaft stock or DC?

 

[LandCruiserPhil]

Is your front driveshaft stock or DC?

Stock and zero vibs to 100, Im part-time for that reason

 

[Pin_Head]

Invsin is "Sin-1" correct?

Good to know, thanks for posting this.

Yes, Sin^-1 is inverse sine

Wow, that's awesome. Are you a engineer?

Not an engineer; a scientist.

 

[Pin_Head]

I used to be a mechanic and a muffler welder too.

 

[bugsnbikes]

has anyone run an offset bushing on the frame side of the arm to correct for decreased wheelbase?

 

[GW Nugget]

has anyone run an offset bushing on the frame side of the arm to correct for decreased wheelbase?

Redline Cruisers is selling one that moves up to 8mm. It's blue, I can't remember the manufacturer name at this moment.

 

[LandCruiserPhil]

has anyone run an offset bushing on the frame side of the arm to correct for decreased wheelbase?

This mod is popular on the other side of the pond to relocate rear mount of the rear of the front control arm.

 

[GW Nugget]

has anyone run an offset bushing on the frame side of the arm to correct for decreased wheelbase?

Also written above there is no decrease in wheelbase till after 4" of lift, it actually goes forward. But I would assume it would be just a small amount either way.

 

[murf]

This mod is popular on the other side of the pond to relocate rear mount of the rear of the front control arm.



View attachment 1435104

also in the states: Land Cruiser Parts - MAN-A-FRE

 

[FJP971]

@FJP971 Those look spot on.

Any recommendation on what I can do to get in spec?

 

[GW Nugget]

Any recommendation on what I can do to get in spec?

There are a few that are working on adjustable plates at this time. Infact @landtank & @NLXTACY are.

Since you have the Yellows that should of corrected 3.4 degress of the 1.7+1.75+.91=4.36 that needs to be corrected, it hard to say. I've been where you are but with 3.5" of lift. I had yellows plus the 2" MAF brackets (which worked great) now still needing more caster after I replaced with stock bushings. I'm waiting on the adjustable plate option coming soon.

 

[ElJayBird]

Have OME 2.5 inch lift and replaced & corrected castors accordingly with this.


Old Man Emu Caster Correction Review

View attachment 1432020

I installed these after my OME 2.5" lift and I'm still -1.8 under caster spec. I need to be +2.8 degrees more to be at 3 deg. YMMV, but I'm trying to find a better solution.

Edit: After reading through this thread and the MAF site, I'm going to give them a call and probably order the control arm drop plates when I get back from my trip to Yosemite. Hopefully I can run the 2" plate in conjunction with the OME bushings to get my caster back to spec. I'll add in the sway bar drop brackets as well while I'm at it.

The truck should handle great after those...I would think anyway.

 

[landtank]

There are a few that are working on adjustable plates at this time. Infact @landtank & @NLXTACY are.

Since you have the Yellows that should of corrected 3.4 degress of the 1.7+1.75+.91=4.36 that needs to be corrected, it hard to say. I've been where you are but with 3.5" of lift. I had yellows plus the 2" MAF brackets (which worked great) now still needing more caster after I replaced with stock bushings. I'm waiting on the adjustable plate option coming soon.

My plates won't be adjustable. Like my original plates you will have s pilot hole where you drill a new front hole in the axle bracket.

Toyota provides a 2* range for caster. So the idea is to target the 2.5" with an end result of 3*. When you apply Toyota's range it looks like this,

3.0" lift would be @ 2* of caster
2.5" lift would be @ 3* of caster
2.0" lift would be @ 4* of caster

Looks like the first prototype will arrive next week.

 

[Cruiser804]

Apologize if these are dumbass off topic questions. I have the OME yellows that were installed without the LT template. I have the template now. Caster is not with in spec. Can't find the last alignment doc ATM.

1.) Can the bushing be removed and repressed? Is that a bad idea? Seems like it might be.
2.) If that can be does it make sense to redo them with the LT template.

 

[Pin_Head]

If the front offset is down and the back one up, that is about as good as it gets and it won't be off more than a few tenths of a degree.
The bushings are only good for about 2 inches of lift, so that may be the problem.

 

[Dervis Garip]

I installed these after my OME 2.5" lift and I'm still -1.8 under caster spec. I need to be +2.8 degrees more to be at 3 deg. YMMV, but I'm trying to find a better solution.

Edit: After reading through this thread and the MAF site, I'm going to give them a call and probably order the control arm drop plates when I get back from my trip to Yosemite. Hopefully I can run the 2" plate in conjunction with the OME bushings to get my caster back to spec. I'll add in the sway bar drop brackets as well while I'm at it.

The truck should handle great after those...I would think anyway.

With my 2.5 lift I just followed the standard diagram that the bushes come with in this pack and aligned it according. Was a no brainer really didn't even calculate anything.

I felt a huge difference afterwards as the noise of the car is corrected.

Slee - OME Suspension Installation (Toyota 80 Series Land Cruiser)