Running out of ideas - death wobble at <30mph

[Ed Poore]

If its only angled bumps that do it I'd put money on it being the panhard rod bushes.

In my experience I've had wobbles, bushes look okay but when I take it off and replace the wobble goes away.

If you can have a look out the window when the wobble kicks in, if you see the axle moving in and out with respect to the body then almost certainly shot bushes on the panhard rod as that's what keeps it all in line. There may also be other bushes contributing too.

[miketomcat]

41 minutes ago, Carloz said:

Interesting...

I have a bit of the same thing (on much higher speed) with a 1986 Range Rover, completely standard setup with RRC '92 alloys with 235/70-16.

In general use it behaves very well but when hitting angled bumps on the highway (while crossing angled viaducts for example) @ arround 110/120km/h it can get very violent! When that happens you know you are alive, if you were in doubt!

 

All is checked a couple of times. A RRC has the steering damper is new and on the best spot to prevent these kind of things: on the track rod. It happens with and without 30mm spacers. And stil after replacing the steering box (because of a leak).

So... after reeding this it seems difficult to detect the amount of play that can already cause this problem. My RRC has done +300.000km so it seems a rebuild of the front axle is the only way to solve this.

Yours sounds like classic death wobble, I would check/replace panhard bushes and track rod ends.

Mike

[Snagger]

With that mileage, I’d expect the swivel bearings to be a bit worn and their preload to be out of spec.  I’d also be looking for wear in all the rod ends and the steering box.  I’d they haven’t been done before, your suspension bushes must be well due for replacement, and the Panhard Rod bushes above all others should make a difference.  But do get the tracking checked.  If you have parallel or toe out set, your car will be all over the place when you hit uneven surfaces.

[FridgeFreezer]

@Carloz as the replies above say, it's not the axle, it will be the bushes and/or the swivel kingpin bearings. If the kingpins have a little play in them it will absolutely cause this when hitting a bump, I've had the same thing with mine as the original Volvo kingpins are known to wear fairly quickly.

[Carloz]

Ok, thanks for your useful replies and sorry for the hi-jacking of this topic! 🙂

[Ed Poore]

19 hours ago, Snagger said:

With that mileage, I’d expect the swivel bearings to be a bit worn and their preload to be out of spec.

May well be depending on usage but over the last 180,000 miles (same distance as we're talking about here) my 110 has had a hard life and every time I've gone to check the swivels and bearings they've been absolutely fine.

Might be the exception but they've not been touched since new in 1994. When I bought it it had a full and detailed service history so I'm confident they haven't been changed, I bought it with 50k on and it's now over 230k miles and I've certainly not touched them other than checking for play and preload.

[uninformed]

Given the small amount of rotation  in the swivel bearing during use, a parked up vehicle may actually end up worse. 
 

Death wobble can be a bugger to get to the bottom of given the variables. Tyres, Panhard and swivels are the go to, but it can be as simple as a dead dampener or even a dampener bush. Even steering dampeners can lose their effect just either side of straight ahead and not help (though that shouldn’t cause it if everything else is correct, it just doesn’t help)

[Carloz]

2 hours ago, uninformed said:

Given the small amount of rotation  in the swivel bearing during use, a parked up vehicle may actually end up worse. 
 

Death wobble can be a bugger to get to the bottom of given the variables. Tyres, Panhard and swivels are the go to, but it can be as simple as a dead dampener or even a dampener bush. Even steering dampeners can lose their effect just either side of straight ahead and not help (though that shouldn’t cause it if everything else is correct, it just doesn’t help)

Well, I think all is the original stuff from 1986... this RRC is in a quite rough shape, I have not the idea that it was taken care for. Imported from southern France before I bought it, so rust on the common places but a little less..

Only the steering damper was new when I bought it 8 years ago.. The former owner had some intresting highway experiences too I guess.. but didn't tell me of course. 

From 2014 I took the original VM 2.4TD out and put a '74 V8 in it, which was laying around in my mancave. The VM was ok but the roadtax for diesels in the Netherland is not. Also changed to V8 front springs and also changed shocks and their bushes with no result. So it must be something to do with panhard bushes, trackrod ends and/or kingpin bearings... So.. on the to do list..

 

 

[Snagger]

A steering damper only reduces wobble - it can’t be the cause.  If the swivel bearings, wheel bearings, steering joints and suspension bushes and tyres are all good, you shouldn’t get any wobbles.  Even bad tracking adjustment, which can cause dynamic instability, won’t cause wheel wobble.