Caster Correction Options, Differences, and Opinions

[bpassmore]

First off, I do not want to start a vendor war.

I want to have a nice discussion of the options for caster correction and the pros and cons of each one. We have several options when we are looking to fix our rig's on the road squirreliness after a lift.

1. Caster correcting bushings
2. Caster correction "plates"
3. Dropped control arm mounting bracket
4. Replace control arm with caster corrected unit.

We have multiple options for most of these above options.
What i would like to see is the pros and cons of each. Such as, apparently there is a difference in the Landtank and Slee plates. Slee's apparently doesn't place the pinion angle correctly, and Landtank's does (maybe?). These are very confusing and I would like to get Mud's members' opinions, thoughts, and experiences.

Once again, I am not trying to slam or slander anyone or any product. I just want a good assessment for the community.

Thanks.

 

[Liftman]

i am about to do this as well,hope to hear opinions and an idea how they are fitted.

 

[Nay]

Do a search for "caster" under the username "Landtank" and delete this thread

 

[Ebag333]

Do a search for "caster" under the username "Landtank" and delete this thread

x2

This has been covered about a million times in a million threads.

Plus, caster is going to be extremely rig specific. Since caster specs are acceptable over several degree's, two identicle rigs could use two completely different solutions and still fall in spec (depending on where they started at).

Doing your research by searching through old threads, then posting up if you have a specific question is really the best solution. Well, the best solution short of calling someone like Slee.

 

[sleeoffroad]

Such as, apparently there is a difference in the Landtank and Slee plates. Slee's apparently doesn't place the pinion angle correctly, and Landtank's does (maybe?

This is not correct. And this is also not to start a pissing match. The caster and pinion angle is connected to each other physically and can not be changed independently, doesn't matter how you rotate the axle.

Lantank and our plates do rotate the axle differently but if he ends up with 2 degrees of caster and I end up with 2 degrees of caster the diff pinion angle will be the same. You can not decouple those. The knuckles are bolted to the axle housing as is the diff.

Now for a DC shaft to work, you want the pinion to point at the transfer case. This is defendant on lift height. Imagine you leave the axle on the ground and you extend a straight line through the pinion perpendicular to the pinion flange. Now you raise or lower the frame (with the drivetrain) (ie, lift). At some point the line will point straight at the transfer case output flange.

The difference is that with Landtank's plates and ours, this does not happen at the same point, ie lift height.

 

[bpassmore]

Christo,

Thanks for replying to this. That is what I thought. I don't see a big advantage of using one over the other (other than the installation), and that is why I am asking. You have helped clarify this for me.

So essentially, if I choose the plate option, then the only difference in the functionality of the two options is that yours is more of a bolt-on option.

Again, I am not criticizing, I am consolidating the opinions into one thread.

 

[landtank]

Depending on how you rotate the axle depends on what other alignments are affected.

Frankie recently wanted to do some testing with my bushing templates. So I sent him one for each of his bushings. He pressed out the bushings which was installed according to the factory guide with one up and one down and re-pressed them in with my template. He noted a marked improvement in the trucks handling. I don't think that my templates added any more caster to his truck. But my temples do rotate the axle on it's axis and minimizes any alteration to other geometric alignments such as spring perches, panhard mounts, axle distances on the arms and so on. It's these other alignments that will also influence the handling and outcome of the job.

As far as Christo's comments that 2* is 2* for pinion angle, that is false. That only holds true if all the other dimensions are the same. Since his plates hinge the axle on the rear bolt then the axle's distance from the rear arm mount is shortened and this effects the pinion alignment to the t-case. It actually makes the pinion angle greater at any given caster correction than mine.

This isn't to say that his angle is not the same as mine but we definitely don't share both caster correction and pinion angle. it's physically not possible. So when comparing our two plate systems it's not as simple as to which one is easier to install, it goes a lot deeper than that.

I've installed both his plates and mine and will tell you his are easier and less time consuming but does require a welder.

 

[sleeoffroad]

I think this thread is fine and we can have a good discussion on the methods, however you will probably not get an answer for your needs out of it


[*]Caster correcting bushings

PROS
* Simple mod for low corrections
* Inexpensive
* No loss of clearance.
* All OE hardware and liability issues for supplier

CONS
* Need a hydraulic press to do.
* One shot deal, bushings can be messed up with install
* Alignment of bushings can be an issue
* Loose flexibility of oe rubber bushings.

[*]Caster correction "plates"

PROS
* Simple mod for moderate corrections.
* Inexpensive.
* Uses factory Toyota bushings so you have the flexibility of rubber bushings.


CONS
* Due to more rotation than bushings, tie-rod interference can be an issue.

[edit]
* Axle rotation can bow the spring due to design of caster plates. Slee plates does this to a certain degree, but Slee are a direct bolt on with little cutting of axle brackets. Ours are easily reversed with no modification to existing mount holes on axle brackets.
Landtank brackets does not have the negative on spring bow due to design, but more complicated install due to drilling of holes. Not easily reversible since holes can overlap existing holes. [/edit]

[add]I wrote the above fist, but then thinking about it more, what makes it clearer (as seen in drawings below) is that the relationship of the axle to the arm is different for Slee plates VS Landtank plates, however at some point during the arc that the spring travels both setups will bow the spring. It will just happen at different points during the travel of the arm. [/add]

* In both cases more liability for supplier since hardware is replaced.

* Does not address the fact that axle moves back, but at lift heights were plates work, this is not a big movement.

* Can not be used with caster bushings.

[*]Dropped control arm mounting bracket

PROS
* Puts axle in stock position since it drops it straight down
* Loss of ground clearance
* More liability for supplier due to movement control arm location.
* Interference with sliders.
* Uses factory Toyota bushings so you have the flexibility of rubber bushings.
* Caster bushings can be used to adjust range of arm's correction. + or -

[*]Replace control arm with caster corrected unit.

PROS
* Addresses axle position with longer arms.
* Higher caster correction without interference of tie-rods
* Uses factory Toyota bushings so you have the flexibility of rubber bushings.

CONS
* Expensive to make
* High liability to supplier if not deigned or produced correctly. This is overcome by engineering of the arm and testing of the product.


This is just a quick list of the top of my head. I probably did not cover everything.

 

[sleeoffroad]

Depending on how you rotate the axle depends on what other alignments are affected.

Frankie recently wanted to do some testing with my bushing templates. So I sent him one for each of his bushings. He pressed out the bushings which was installed according to the factory guide with one up and one down and re-pressed them in with my template. He noted a marked improvement in the trucks handling.

What was the improvement?

I don't think that my templates added any more caster to his truck. But my temples do rotate the axle on it's axis and minimizes any alteration to other geometric alignments such as spring perches, panhard mounts, axle distances on the arms and so on. It's these other alignments that will also influence the handling and outcome of the job.

This is purely like hearsay and I can not see that those differences can make that much of a difference. I would really like to see your drawing that shows the differences on these mounting points and how they change with the differences in rotating methods.

As far as Christo's comments that 2* is 2* for pinion angle, that is false. That only holds true if all the other dimensions are the same. Since his plates hinge the axle on the rear bolt then the axle's distance from the rear arm mount is shortened and this effects the pinion alignment to the t-case. It actually makes the pinion angle greater at any given caster correction than mine.

There is no physical way that one axle at 2 degrees caster can have a different pinion angle vs another at 2 degrees, unless there are physical differences in how the balls on the end are welded to the axle housing or the diff mounting flange is welded to the housing.

The pinion flange can be at a different point in space, but not at a different angle. The different spot in space can affect if it points at the transfer case or not. But neither is better than the other since the lift height is also a factor.

I did not saying a 2 degree rotation for caster is a net 2 degree in pinion rotation. I said if we both set the axle at 2 degrees measured caster, then the pinion angles will be the same.

This isn't to say that his angle is not the same as mine but we definitely don't share both caster correction and pinion angle. it's physically not possible. So when comparing our two plate systems it's not as simple as to which one is easier to install, it goes a lot deeper than that.

Yes, there is a difference in how the axle is rotated, but for a given caster result (not amount of caster change), we have to net the same pinion angle.

I've installed both his plates and mine and will tell you his are easier and less time consuming but does require a welder.

We ask for the plates to weld on as an additional safety. Most likely not needed but not a bad thing to do.

 

[landtank]

Sorry for the confusion, I was trying to keep my wording along what was already said to help in the understanding.

Yes the pinion angle will be the same but the actually working angle of the u-joint will be different. And in the end it's that angle that is most important.

I can draw up an easy to understand picture in CAD if anyone wants, just ask.

 

[Waggoner5]

I would imagine that there would be a difference, otherwise there would not be a market for both, but the bottom line is that they both work and with years of threads like this, why start another one? Every truck is different.
Some types of correction will work for some trucks and not for others. Lift height, tire size, type of wheeling, spring/shock combo, truck weights, where weight is distributed, etc will establish what type of correction will work for you.
Ricks stuff is very well thought out and proven tried and true, and Christo is they guy that invented the 80 market that builds hundreds of 80 series products for us, putting more hours of testing and thought into these products than all other vendors combined, so how can you go wrong with either?

 

[Waggoner5]

Slee's apparently doesn't place the pinion angle correctly, and Landtank's does (maybe?)

Do you think that any vendor would go to all the trouble to design and build something that would adversely affect one of the primary reasons for building such a product? I can assure you that both Slees and Ricks parts are well thought out and well designed.

 

[sleeoffroad]

Yes the pinion angle will be the same but the actually working angle of the u-joint will be different. And in the end it's that angle that is most important.

For a given fixed caster value, with the wheels on the ground, the pinion angle flange will be the same does not matter what was used to get the axle in that position. (assuming 0% differences in how things were welded together)

The only thing that changes is how the vehicle is bolted to the axle housing via the arms. So Lantank's plates, our plates, bushing or arms all changes this relationship of the vehicle to the axle.
The only thing that can happen is that the pinion flange can be moved forwards or backwards in relation to the vehicle. The axle is exactly in the same position in terms of rotation. So the spring perces, panhard mount etc etc are all the same.

But if you lift the vehicle relationship to the axle changes. Consider the axle fixed at a fixed caster and the tires are glued to the ground. The trucks position to the axle can be different. The front can be lifted more than the back, etc etc. That is where the operating angle of the drive shaft comes in.

So far a given lift height, with Landtank's plates set at a certain amount of caster correction there is a spot where the operating angle is ideal. That does not mean it does not happen with our plates as well. Since the correction on our plates and his are not the same, this will not be the same lift height.

If we took the time to put a truck on the alignment rack and did a custom install (ie, drilled the holes custom) with our plates to yield for example 3 degrees of measured caster and you did the same with Landtank's plates on the same truck, the only difference with how he rotates the housing we we do it is that for ours the pinion flange will move slightly back. This movement of the pinion flange can effect the operating angle of the u joints (since the relationship of the front pinion angle is different to the transfercase flange), however I would like to see how much this backwards movement actually is.

This movement back is also where the differences in contact of tie-rods with control arms come in. Since our movement also moves the tie-rod back a little, it moves higher up on the arc of the control arm and might rub earlier than his.

I can draw up an easy to understand picture in CAD if anyone wants, just ask.

I am asking

 

[landtank]

here you go.

In the pic below the black round circle on the left with the slanted "T" coming out of the center would represent the diff in the stock location. The same shapes in red would be one that is shifted to right as if the axle's position on the arms has been shortened.

In the upper right corner the black horizontal "T" would be the t-case flange.

The blue line the drive shaft connecting the black diff to the t-case and is at a parallel angle to that of the pinion giving 0* in the operating angle of the front ?U-joint.

The green line is the driveshaft connecting the red diff to the T-case and is not parallel to the pinion increasing the operating angle of the front u-joint as well as at the rear.

Because of the differences of how our plates alter the position of the axle they are not going to yield identical results.

 

[Nay]

Do a search for "caster" under the username "Landtank" and delete this thread

Did I nail this or did I nail this ?

 

[Waggoner5]

I see the difference, but isn't that why there are aftermarket arms for the taller lifts? I can see both plates working fine with marginal lifts, but see that Ricks will work more in spec with lifts that fall in the "difficult to fix" area.
Using this drawing as a reference, where do OME bushings put the angles with the same lift formulas?

 

[OGBeno]

Not this again....didn't we discuss this in 2003, 2004, 2005, 2006, 2007?

 

[Waggoner5]

Not this again....didn't we discuss this in 2003, 2004, 2005, 2006, 2007?

Yep, not sure I understand it either, but I can't back down from a good fight

 

[jasonmt]

Because of the differences of how our plates alter the position of the axle they are not going to yield identical results.

So what would the actual differences in both front to back and up-down position be between the two different plates with the same given lift height, lets say 4" over stock? 1/8"? 3/16"? 1/4"? More? Less?

 

[Bikeman]

First off, I do not want to start a vendor war.

I want to have a nice discussion of the options for caster correction and the pros and cons of each one. We have several options when we are looking to fix our rig's on the road squirreliness after a lift.

1. Caster correcting bushings
2. Caster correction "plates"
3. Dropped control arm mounting bracket
4. Replace control arm with caster corrected unit.

We have multiple options for most of these above options.
What i would like to see is the pros and cons of each. Such as, apparently there is a difference in the Landtank and Slee plates. Slee's apparently doesn't place the pinion angle correctly, and Landtank's does (maybe?). These are very confusing and I would like to get Mud's members' opinions, thoughts, and experiences.

Once again, I am not trying to slam or slander anyone or any product. I just want a good assessment for the community.

Thanks.

This is dumb. You guys can argue all day. Your truck will need "X' caster correction at "X" lift. Choose what you need. You can't go wrong as long as you get caster into spec. But what about guys like me with 5-6" of lift.? I have no option to compare. I have to go with new arms.