Castor problem?

[blakesrover]

if re-drilled swivel, castor corrected arms, and DC shaft upfront cures both castor and vibration, is there a need for a TT? and if so, what is the need?

second, do guys run TT upfront to replace front lockers or is it purely for steering correction (band-aid)?

third, my application came with center diff. what would be more beneficial as a whole; lockers in the rear or upfront?

~Blake

[revor]

Here's what I've done. Do the caster corrected arms, If that completely blows your no vibe world put in a DC driveshaft.

In reality a D1 should have come with one from the factory, instead they chose to do some sort of wierd "off phase" arrangement with the single cardon shaft.

Look at the factory alignment of the pinion shaft and the output shaft of the t case. in many cases that I have seen the pinion actually points to a point above the output shaft of the t case. Bringing that down so that the pinion points directly at the output shaft indicates that you'll likely need a DC shaft because you've messed with the factory driveshaft black magic.

Or you can do the caster corrected balls, both have benefits.

[Snagger]

Using a locking diff would be masking the problem, not curing it, and could lead to all sorts of odd effects on different surfaces. It may have no help at all in keeping the vehicle straight after a front tyre blow out, which correct castor angle does help with.

Don't elongate the swivel housing bolt holes to do this - it's a terrible botch. Firstly, it's inaccurate, and you'll probably end up with uneven castors from side to side. Secondly, it removes a lot of material from under the bolt head (up to 40% loss) so creates a serious weakness in the joint and will likely end up at some point in the bolts shearing or the swivel flange cracking.

Do the job properly and use either castor corrected radius arms and standard bushes, or standard arms and corrected bushes.

A double cardan jointed front prop will probably be of benefit - the front UJ will have been set to a near straight position by the lift while the rear will be more steeply cranked, which will render the factory UJ phasing out of required spec. The rear is unlikely to be a problem unless you have a worn UJ/rotoflex.

[stevenmd]

Do the caster corrected arms, If that completely blows your no vibe world put in a DC driveshaft.

x2 - should fix everything.

[ntsqd]

Even though it might work for 99% of the folks using it, that doesn't make it the correct way to do it. This is analogous to disproving a theory. All it takes is one event that does not behave according to the theory to blow the theory out of the water.

I wouldn't desire to be that 1% for whom it did not work, so I would not put myself in that position nor will I advise others to do so. The potential for a catastrophe is large.

If the change needed was large enough that new holes had to be drilled, and they were far enough away from the existing holes that the bearing area under the bolt heads would not eclipse the existing holes, then I'd say go for it.

[marc olivares]

Using a locking diff would be masking the problem, not curing it, and could lead to all sorts of odd effects on different surfaces. It may have no help at all in keeping the vehicle straight after a front tyre blow out, which correct castor angle does help with.

Don't elongate the swivel housing bolt holes to do this - it's a terrible botch. Firstly, it's inaccurate, and you'll probably end up with uneven castors from side to side. Secondly, it removes a lot of material from under the bolt head (up to 40% loss) so creates a serious weakness in the joint and will likely end up at some point in the bolts shearing or the swivel flange cracking.

Do the job properly and use either castor corrected radius arms and standard bushes, or standard arms and corrected bushes.

A double cardan jointed front prop will probably be of benefit - the front UJ will have been set to a near straight position by the lift while the rear will be more steeply cranked, which will render the factory UJ phasing out of required spec. The rear is unlikely to be a problem unless you have a worn UJ/rotoflex.

wow, there is a lot of misinformation and conjecture in this post.

[Mike_rupp]

Even though it might work for 99% of the folks using it, that doesn't make it the correct way to do it. This is analogous to disproving a theory. All it takes is one event that does not behave according to the theory to blow the theory out of the water.

I wouldn't desire to be that 1% for whom it did not work, so I would not put myself in that position nor will I advise others to do so. The potential for a catastrophe is large.

If the change needed was large enough that new holes had to be drilled, and they were far enough away from the existing holes that the bearing area under the bolt heads would not eclipse the existing holes, then I'd say go for it.

Virtually every change that we make to these vehicles increases the potential for catastrophe. Lifting the vehicle raises the center of gravity which increases the risk of a rollover. Removing swaybars increases the risk of a rollover. Adding a roofrack and storing things on the rack increases the risk of a rollover. Adding larger tires increases braking distances which increases the risk of a collision.

The risk of these potential catastrophes is much higher than the risk of an issue with enlarging the swivel holes. Also, consider that there is an upside of restoring the caster: reducing wander and improving steering stability.

[Toy-Roverlander]

The weight of the truck is carried by a ring machined into the swivel ball that recess' into the end flange on the housing. the bolts just create the clamping force that keeps it there

Uhm, not entirely so.

At least the bottom row of bolts will be under strain as result of the leverage from the wheel to the swivel flange.

I would personally not enlarge those holes simply because I don't like the idea, but I drive a leafer anyway

just my 2cents
Koos

[ntsqd]

I am not talking in theory here at all...most of the hardest used rovers I know of all have this mod done to them and none have had issues.

the amount of material that is removed is very little and the weight of the truck is not carried in sheer at these flanges. The weight of the truck is carried by a ring machined into the swivel ball that recess' into the end flange on the housing. the bolts just create the clamping force that keeps it there and the total size of the area left after the machine work is done is still about 20x the size of the welded area on a toyota weld on swivel ball.

So you discount that area lost under the bolt heads and call it good?

Tell me, with that lost area and the bending load incurred on the bolt by that loss, what insures that the setting won't change at the most inopportune time?
That it never has is not good enough, that's a matter of fortune and not design. Mr. Murphy adores sloppy construction methods.

Virtually every change that we make to these vehicles increases the potential for catastrophe. Lifting the vehicle raises the center of gravity which increases the risk of a rollover. Removing swaybars increases the risk of a rollover. Adding a roofrack and storing things on the rack increases the risk of a rollover. Adding larger tires increases braking distances which increases the risk of a collision.

The risk of these potential catastrophes is much higher than the risk of an issue with enlarging the swivel holes. Also, consider that there is an upside of restoring the caster: reducing wander and improving steering stability.

Since most of the mods we make change the vehicle dynamics, in usually a negative direction, does it not behoove us to address those that can be controlled or reduced and do so to our utmost?

[blakesrover]

Well, either way you look at it. I remember a post of a catastrophic failing control arm on an LR3, i think pretty recently. And that was a stock component.

What i do focus on at this point in time is what i have on hand. A truck with not enough castor for my comfort. So that is my first fix. What direction to take, well, that is still in the air. it's not a matter of where i take my business, but more so the best solution. Money should not be an issue either when considering something of this seriousness.

If re-drilled and castor corrected control arms both skin the cat, which one is the safer way of skinning?

Since there is potential question of re-drilled swivel, although nothing has ever been documented, are there any "potential" or documented issues with castor-corrected control arms?