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Kingpin bearing play

Posted: 14 Jan 2018 20:57
by Florian320
Hello guys!
A friend has a slight shudder with his 4.8 Patrol when doing about 120 and driving over bumps or small holes.
We are both not sure if this as normal but have a feeling it‘s not.
As he had the death wobble the dealer basically changed the whole suspension with that of a new car.
That made the wobble go away, but that shudder remains.

We are wondering if the kingpin bearings could be rhe culprit. The shims already have been taken out by the previous owner.
My friend got the bearings out and found about 1-2mm play in them - is that all right, or should they have close to zero play? You could easily see the lateral movement of the bearing which to me feels a bit much of play.
Is there a rough maximum?

Re: Kingpin bearing play

Posted: 15 Jan 2018 05:04
by Peter Connan
I am not sure I inderstand.

Un-installed bearings will always have lots of play. However, in the installed position they should not have play.

It is possible that they could have play even with the shims removed. Unfortunately the onlyway to check if they are loaded correctly is to remove the side-shafts and the hub scraper/seals and then measure the force needed to turn the hub. Any other procedure is risky, as if you over-load these bearings you stand the risk of cracking the hube carrier casing.

But this sounds like there may just be a little bit of play in the steering (tie rod ends or steering box), possibly also the steering damper?

Re: Kingpin bearing play

Posted: 15 Jan 2018 08:21
by Florian320
Hi Tinus, thanks a lot for the reply!
Especially that the play we saw doesn't mean anything.
The car had the death wobble. As the dealer wasn't able to sort that by exchanging single parts, he changed the whole underpart below the frame of the car with that of a new one.
So any rod, damper, coil, bush, the steering damper aso is brand new.
That eliminated the death wobble.
The steering is stiff and has zero play, even on dust roads.
But when you drive at higher speeds (120km/h) and you hit a slight dump on the street you will feel a shudder like something is rebouncing. It's hard to explain, it feels like something would vibrate up and down being a tad loose for a short time, like 5-6 times.
I do have the same feel with my car but now as pronounced as with his and my car wouldn't give any feedback of that to the steering wheel whereas my friend's steering wheel would give that feedback.

As I said, it is quite a possibility that this is normal - that is what I am trying to find out.

Re: Kingpin bearing play

Posted: 15 Jan 2018 09:24
by Clem
Have you guys had the shocks tested? Sounds like it could be a dodgy shock.

Re: Kingpin bearing play

Posted: 16 Jan 2018 16:13
by Florian320
Also the Shocks have been changed with new ones. So if they were broken they must have been broken in the same way the old ones have been.
I think that is not very probable.

Re: Kingpin bearing play

Posted: 16 Jan 2018 16:48
by hugejp
Do you feel the shudder through the steering wheel or through the floor?

Re: Kingpin bearing play

Posted: 18 Jan 2018 06:03
by Florian320
Definitely through the steering wheel.