Caster Correction for a 2.5" Lift

[GW Nugget]

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)

View attachment 1435353

I measured the difference of the yellow arm on top of stock one like in your pic & it was 1.5" center to center difference.

 

[landtank]

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.

I don't believe this is entirely correct when talking about out trucks.

Your calculations are based on starting at a fixed horizontal position and then increasing by an inch each time. Our situation is again starting at 2 inches above horizontal and then passing through that point to the other side.

So using your numbers:

First inch 1.75
Second in 1.70
Third inch 1.70
Fourth inch 1.75
Fifth inch 1.83
And then so on.

 

[FJP971]

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.

Do you know what your caster was before the plates? I'm at 23" also which should be 2.5" of lift using the Landtank calculation.

 

[LandCruiserPhil]

Do you know what your caster was before the plates? I'm at 23" also which should be 2.5" of lift using the Landtank calculation.

No

 

[ElJayBird]

Do you know what your caster was before the plates? I'm at 23" also which should be 2.5" of lift using the Landtank calculation.

Are you at 23" even on both front and rear?

 

[FJP971]

Are you at 23" even on both front and rear?

No, rear is 24 1/4" without anything in the interior i.e. drawers and gear that will be added.

 

[landtank]

Plates arrived yesterday. I'm in contact with a local guy and hope to have the first set installed next week.

 

[ElJayBird]

Can't wait to get a set of these

 

[landtank]

Right now the plan is to install them on Sunday. We have also ordered front u-joints as well.

Often you can get vibrations after a lift because the joints now work in a different range than were they did before

 

[landtank]

OK, plates were installed. I used a digital angle finder and set the pilot hole on the strong side. This allowed the position of the front hole that was to be drilled to be centered between the original hole and the edge of the bracket. This would allow someone to easily revert back to the stock location by just removing the plates.

Took it out for a drive and no vibrations or any handling problems. Truck is going on an alignment rack to get hard numbers.

 

[Dragos80]

Is this truck sitting at exactly 2.5" over stock height, as the title implies?

Asking to see if there is some wiggle room for 2-3" lift.

 

[landtank]

Yes it was. The idea is to target 3* of caster at the 2.5" amount of lift. Since Toyota's spec for caster is 2-4* there is a range that we can work with in.

Since caster changes about 1.75* per inch a that range is more than an inch.

So a safe range would be a lift height of 2-3 inches. A 2" lift would have around 4* of caster and a 3" lift would have around 2* of caster.

 

[BerettaMato]

I went plate after bushing were still causing floating on the road. Slee castor now and it feels like stock steering and no floating, I have a 3" lift in front after weight added. Cant speak to others.

 

[Mandrake]

Has anyone used the camber/castor trunnion bearings like these?

Slee - Toyota 80 Land Cruiser Suspension Bushings (scroll to the bottom)

 

[landtank]

I went plate after bushing were still causing floating on the road. Slee castor now and it feels like stock steering and no floating, I have a 3" lift in front after weight added. Cant speak to others.

After going through this, caster bushings aren't going to be enough.

My goal was to only add enough caster to hit my target as previously described. Tilting the axle beyond that risks driveline vibrations, tierod contact with the front arms and spring contact with the spring bumpstop.

 

[ARB777]

OK, plates were installed. I used a digital angle finder and set the pilot hole on the strong side. This allowed the position of the front hole that was to be drilled to be centered between the original hole and the edge of the bracket. This would allow someone to easily revert back to the stock location by just removing the plates.

Took it out for a drive and no vibrations or any handling problems. Truck is going on an alignment rack to get hard numbers.

Do you make one with the actual holes already? Ive been wanting to buy your plates but dont have the capability of drilling the hole from the pilot hole.

 

[DudeAbides]

Has anyone used the camber/castor trunnion bearings like these?

Slee - Toyota 80 Land Cruiser Suspension Bushings (scroll to the bottom)

Yep, installed a couple years ago. No issues so far, and no vibrations with the stock driveshaft.

 

[landtank]

Do you make one with the actual holes already? Ive been wanting to buy your plates but dont have the capability of drilling the hole from the pilot hole.

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Your drilling new holes in your axle bracket as well as the plate. The plates supply the pilot hole for positioning the hole and supporting the bracket now that it has been weakened from drilling the holes

 

[Dragos80]

If someone is totally possessed and wants to go back to stock height, is there a problem taking the plates out since the axle brackets were drilled?

 

[Noahrob]

subscribed! I am going down the custom built washer mod approach, but am 100% open to learning better approaches.