Steering shake continuation

So, rather than hijacking the Steering Shake thread, I'll start a new one.

I took the beast to Bob Jane's at Cleveland this morning. An hour or so after I dropped it off, I got a phone call. One of the tyres had a "separation", where the air had somehow got between the radials and the rubber. Something like that.

To their credit, they didn't charge for the other three tyres they balanced. Nice. However I am up for a set of new rubber now, so it was a very hollow win.

New tyres will need to wait for funds to be available, so I brought the car home, ready to take out the king pin shims.

Tip for fellow newbs... If your car has been raised, get a high lift jack!

Anyway, I propped the front end up and got to the dirty work of removing the shims. Lo and behold, there weren't any. And what a pain in the rear, getting them I'm and out, particularly the bottom ones. Urgh.

I checked them all (all were fine) then went through the drama of jamming the things back into their holes. I wish my garage was higher as I was doing this in the midday sun too.

Changed the dodgy tyre with the spare until I can get new ones. Have yet to take the thing for a spin, but I'm not expecting the wobbles to have gone. Any suggestions as to where to go from here?

Thanks
Luke

Update!

No idea what I did but the wobbles are gone. Woot!

Did the steering shake on the way home from Bob Jane? and did you re-grease the bearings before you put them back in?

Did you grease the races?
also the rollers may have a flat spot which is now else where.
I had no drama removing or replacing my king pin bearing cariers as I supported the axel on stands removed the wheel and just kised the jack onto the hub to take the weight did bottom first easy!, then top no dramas.
However like you It may come back if it does then I'll change the races as it may be flat spotting of the rollers
Good luck

Peter, yeah it definitely wobbled on the way home from BJs.

I regreased the bearings. They had plenty there already though. Maybe it was a flat spot.

Joe, it certainly would have helped to have jacked up the wheel slightly. There was a definite gravity effect taking hold. Alas, good ideas like this don't occur to me. Sigh.

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Originally Posted by JoeG

Did you grease the races?
also the rollers may have a flat spot which is now else where.
I had no drama removing or replacing my king pin bearing cariers as I supported the axel on stands removed the wheel and just kised the jack onto the hub to take the weight did bottom first easy!, then top no dramas.
However like you It may come back if it does then I'll change the races as it may be flat spotting of the rollers
Good luck

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I agree with JoeG but if you do replace the bearing I recommend you put in new shims also.

At least we know its not caster hey lol

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Originally Posted by peterbr1

At least we know its not caster hey lol

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It could be as he does mention the vehicle has been raised.

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Originally Posted by nissannewby

It could be as he does mention the vehicle has been raised.

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The wobble has stopped

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Originally Posted by peterbr1

The wobble has stopped

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... and the cause in this particular case was...?

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Originally Posted by the evil twin

... and the cause in this particular case was...?

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Im leaning towards JoeG's explination

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Originally Posted by the evil twin

... and the cause in this particular case was...?

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He must be good. He knows they have stopped before the owner of the vehicle has even driven it...

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Originally Posted by nissannewby

He must be good. He knows they have stopped before the owner of the vehicle has even driven it...

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The owner did drive it post number 2 "update"

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Originally Posted by peterbr1

The owner did drive it post number 2 "update"

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Interesting.....

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Originally Posted by nissannewby

Interesting.....

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lol.............

If you did nothing but grease the kingpins.
Did you put the assembly back in the same orientation "not spin the carrier around".
I'd bet Originally The flat spot/dibbets in the bearings were lined up giving excess play.
Arrhh, now there misaligned since they were removed & greased, think you've spun the carrier upon reassembly.
this may explain the sudden perceived improvement.

Thanks for the responses so far.

I took the car for a good drive and didn't get speed wobbles at all. As an added bonus (for me, as my attempts at mechanical things don't always go as planned!) there were no remaining screws/bolts, no scary noises, and the steering felt good.

Robo, there is a good chance that the carrier was not set back in the same orientation as it came out. Visual inspection (totes scientific) ended up with me deducing that there is no "wrong" way to put them in. Given that I didn't resort to callipers or other measuring tools, my assumption could be very easily proven wrong.

If the assemblies do have a correct way that I unwittingly got wrong, what would be the result? Given its a car, I assume "catastrophically expensive" is the answer, but what are the details?

so long as they are oem assemblies your cool putting em back in.
yes just the orientation and wear points have/possibly moved

ya can buy off set carriers which move the caster,
the lug the bearing fits on isn't centered.

and offset bearing cups are also available.

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Originally Posted by peterbr1

I agree with JoeG but if you do replace the bearing I recommend you put in new shims also.

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Good point... what size shim is best to use?

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Originally Posted by the evil twin

Good point... what size shim is best to use?

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Thin ones [emoji8]

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Originally Posted by the evil twin

Good point... what size shim is best to use?

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Don't know what thickness shims that might be one for the Nissan stealership people

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Originally Posted by Clunk

Thin ones [emoji8]

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ROFL, typical Clunk....

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Originally Posted by peterbr1

Don't know what thickness shims that might be one for the Nissan stealership people

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Cool... what info do I need to tell them so they get the right ones in for me?

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Originally Posted by the evil twin

Cool... what info do I need to tell them so they get the right ones in for me?

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That you have the wobbles :p

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Originally Posted by nissannewby

That you have the wobbles :p

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Tried that... they said because it was lifted it was a castor issue

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Originally Posted by the evil twin

Cool... what info do I need to tell them so they get the right ones in for me?

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I measured the shims I took out of my car, 0.5mm if that helps

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Originally Posted by peterbr1

I measured the shims I took out of my car, 0.5mm if that helps

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So, you replaced them with new ones the same size and wobbles cured?

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Originally Posted by the evil twin

So, you replaced them with new ones the same size and wobbles cured?

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No around 6 months ago my car developed the wobbles I removed the shims and all is good, I measured those shims I took out 6 months ago and gave you the thickness of them...

from memory .5mm is the thickest one they make.
got me thinking why not make your own shims.
pattern looks easy.
search shim metal sheet.
ebay item no 120898743299
Material - Steel
6 sheets 150mm x150mm
2 x 0.05mm (0.002") thick
2 x 0.075mm (0.003") thick
1 x 0.15mm (0.006") thick
1 x 0.25mm (0.010") thick
approx $30 inc del
Could be of use I recon

.762mm is the thickest shim. Then .254, .127, .075 and .050mm.

Sent from my SM-P600 using Tapatalk

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.

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

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.

[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?

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

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Originally Posted by nissannewby

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

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And your day job is obviously a comedian [emoji12]

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.

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

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.

Oh, and thanks for the comments, everyone.