Steering shake continuation

[the evil twin]

Onya Mudski... sanity at last... I can't be stuffed playing the game anymore.

The shim thickness for the knuckle flanges is determined with a force gauge using a 'selected on test' method.
The combination of OEM shims allows for various thickness in approx .05mm steps to be used so the correct preload is applied.
Previous shim size is irrelevant if the installation has been disturbed so it becomes unique to each assy from measurements obtained with the force gauge.
The method is pretty much the standard engineering practice for low speed, low friction bearing installations.
Install the preload (shims in this case), test the torque, adjust the shims, test the torque, repeat until the correct torque is obtained.

[PullsyJr]

So as a related question...

What the hell do the king pins do? As in, I know the "pre-load tension on the steering" bit, but how? The pin bearings don't seem connected to anything. The assembly slots into place and... sits there...? It can't be putting vertical pressure on the internal hub mechanism as the base of the pin is solid and would thus rapidly just bore a hole in whatever it contacts.

I really don't understand the engineering behind it. Wikipedia is no good for information on it, and my Google-fu is lacking.

Can someone enlighten me about this? Even links to places that explain how it is meant to do anything would be appreciated.

Thanks
Luke

[Robo]

They do take vertical, and horizontal pressure.
all the weight of vehicle sits on em !
King pins (apart from the CV thats to do with drive) are the load bearing device , that allows your "solid beam axle" to have a moving joint and still remain solid.
"that is until the bearings get wear in them", then you can suffer the wobbles Hey.

[peterbr1]

[QUOTE=the evil twin;642624]Onya Mudski... sanity at last... I can't be stuffed playing the game anymore.

The shim thickness for the knuckle flanges is determined with a force gauge using a 'selected on test' method.
The combination of OEM shims allows for various thickness in approx .05mm steps to be used so the correct preload is applied.
Previous shim size is irrelevant if the installation has been disturbed so it becomes unique to each assy from measurements obtained with the force gauge.
The method is pretty much the standard engineering practice for low speed, low friction bearing installations.
Install the preload (shims in this case), test the torque, adjust the shims, test the torque, repeat until the correct torque is obtained.[/QUOT

Were you playing games with me?

[nissannewby]

Evil twin playing games.... pfft never. He's a good guy.

[Clunk]

Evil twin playing games.... pfft never. He's a good guy.

And your day job is obviously a comedian

[Robo]

Correct me if I'm wrong please.
Not preaching, not a mechanic just a bloke trying to put it as plainly as he can to "try" and help others.
Having been through the wobble conundrum 3x on 3 different model patrol now.
MK, GQ & GU, and after trying to fix all the usual problems.

Apart from the usual faults that cause the wobble--
wear and tear on steering components.
worn bushes.
worn wheel bearing and kingpins.
poor wheel balance.
steering damper, which may only mask the wobble.
oh and bent rims, even had brand spanking new rims with a wobble in em.

even caster bushes that allowed to much flex.
solid poly or full factory type rubber caster bushes work best, not the rubber with uneven molded recesses.
some may swear by the rubber bush I don't like, but they made the wobble worse for me before I got that last degree of caster fixed.
And that was pointed out to me by a nissan dealer mechanic, they allow to much flex.
so out of principle I don't use them now, as they "could" cause uneven wear on the tires and set the wobble in motion again, and or create premature wear on all the bits we fix trying to fix the wobble in the first place.

Apart from fixing worn components---
Getting the caster to "Near spec" Isn't good enough,
ya need "factory spec settings to achieve best" outcome.
The only thing in my experience that "truly" fixes the wobble is correct geometry.
Getting a readout of how the caster actually is, and then fixing it, (obviously with other worn parts first), is a "must do".
And not thinking 1 degree can't make that much difference!
m2cw. hope this helps those pulling their hair out, like I did.
expensive lesson learned.

[the evil twin]

Couldn't agree more Robo...

I learnt the same way over quite a few 'Trols.

If the geometry is out, no amount of dicking around with anything else will stop the wobbles

[PullsyJr]

Turns out there might be a few more fundamental problems with the beast. Lots of stuff to consider, replace and maintain. Whilst the wobbles remain abated there are additional underlying issues that will need fixing.

Cars are great until they stop working. Sigh.

[PullsyJr]

Oh, and thanks for the comments, everyone.