Thread: Tyre wear/wobbles/bump steer :(

shocks would/could/should cause the issue.
Depends on shocks tho.
On my RRC, it originally had original(Armstrong branded shocks, and oil - not gas) old and worn, caused some wobble, but you would also notice floatiness I guess .. or other dead shock related symptoms.
Also check shock rubber bushes. Again on my RRC(it did a lot of klms in a short time!) .. they wear out too quickly for my liking, and a small amount of slack between rubber bush and washers caused steering wobble.
But as I remember it, that was usually only in a turn.
Once I got onto Nolathanes(polys) first on the shocks, never had dramas with shock bushes ever again(maybe 300-400K klms afterwards).
Changed the worn shock rubbers straight away on my D1.
I then had Konis on the RRC, and they also wore, but still worked ok. no wobbles no real floatiness, only changed them when I ended up doing the change to polys for the radius arms and all.
Noticed that they felt loose, compressed easily, slack in some parts of their travel .. but never felt bad on the road.
Back to Armstrongs .. they're good for original shocks I reckon.

The common accepted advice is that you don't need castor correction nor adjustable panhard rod for a 2" lift or less.
Dunno if that takes into account larger diameter tyres too tho?

Originally Posted by AK83

shocks would/could/should cause the issue.
Depends on shocks tho.
On my RRC, it originally had original(Armstrong branded shocks, and oil - not gas) old and worn, caused some wobble, but you would also notice floatiness I guess .. or other dead shock related symptoms.
Also check shock rubber bushes. Again on my RRC(it did a lot of klms in a short time!) .. they wear out too quickly for my liking, and a small amount of slack between rubber bush and washers caused steering wobble.
But as I remember it, that was usually only in a turn.
Once I got onto Nolathanes(polys) first on the shocks, never had dramas with shock bushes ever again(maybe 300-400K klms afterwards).
Changed the worn shock rubbers straight away on my D1.
I then had Konis on the RRC, and they also wore, but still worked ok. no wobbles no real floatiness, only changed them when I ended up doing the change to polys for the radius arms and all.
Noticed that they felt loose, compressed easily, slack in some parts of their travel .. but never felt bad on the road.
Back to Armstrongs .. they're good for original shocks I reckon.

The common accepted advice is that you don't need castor correction nor adjustable panhard rod for a 2" lift or less.
Dunno if that takes into account larger diameter tyres too tho?

Yup, i just bought a set of caster correction bushes as with the 235 tyres as i get a bit of bump steer.
My shocks are 4-stage adjustable terrafirmas. They are all good after 50k on all wheels but the front left wheel caught a bit of an impact on a spoon drain over in NSW... haha.

It will probably take a week or more to get some parts then I will replace the radius arm bushes and shock absorber and then see what the suspension/steering is behaving like...

Look very carefully at the front left hand tie rod end when someone moves the steering. Wear here causes the tyre wear you are describing and lousy handling.

Originally Posted by Finnius

Hey folks,

I have my front left tyre wearing out on the outside edge of the tyre much more than the inside. I also have considerable bump steer/wobbles when i hit bumps on the bitumen.

The D1 my son drives, not long after purchase and with new tyres, had the same issue but on the left front.

There are a number of turns of thread that each ball joint must protrude beyond the end of the drag link and track rod.

Just because the distance between ball centres is 924mm and 1230mm respectively (as per manual) does not mean the geometry is correct if the extra step of setting the thread distance is not done correctly.

Drivers side ball centre to drag link end is 28.5mm, the other end wound in/out until ball to ball centre is 919mm. Drivers side ball centre to end of track rod is also 28.5, and ball to ball centre 1230.

Hopefully this is your cause, as it is a relatively easy fix for the DIY.

Not so much for what I've described above, but, keep in mind there is a slot in the drop arm that aligns with a small hole on the steering box, usually locked in place with the appropriately sized drill bit while you set your geometry etc. If you think you're good to go, but the slot and hole don't align then start over.

Originally Posted by Finnius

Thanks guys!

Wouldn't it be too much toe-in causing wear to the outside edges of the tyre?



Anyone know what the correct toe-in degrees/mm difference between front and back is meant to be? Something i can measure with a tape measure...
My workshop manual says "X-Y= 0 to 2mm" with x front measurement between tyres and y back measurement between tyres.
But 0 would mean no toe-in and 2mm would mean slightly toe-out... :/

Yes its 0-2° toe OUT. Most tyre shops do not have the D1 setting and go off the D2 which I believe is different, maybe someone with a D2 can confirm that please. Last time I had an alignment done I told the bloke to do it manually to 0-2, after raising on the hoist he asked me what does what *face palm* 3 months later i find my track rod hanging on by a thread and rattling around....
Cheers Jim

So i redid lots of my front suspension setup.
I replaced shocks (which improved the swayiness), adjusted wheel bearings (which virtually removed the wobble), checked the panhard bushes, already had near new steering rods and balljoints, and installed castor adjusted radius arms (no more bump steer). I was a happy camper for a little while

But now on decceleration/coasting when i take my foot of the accelerator sometimes if the road has a couple of bumps i get a little bit of a wobble/shake which sometimes feels like it starts oscillating and gets worse and worse for a few seconds. I usually accelerate to stop the shake. As far as i can tell this only ever happens on deceleration...

Anyone ever heard of this before?

Originally Posted by Finnius

.....

But now on decceleration/coasting when i take my foot of the accelerator sometimes if the road has a couple of bumps i get a little bit of a wobble/shake which sometimes feels like it starts oscillating and gets worse and worse for a few seconds. I usually accelerate to stop the shake. As far as i can tell this only ever happens on deceleration...

Anyone ever heard of this before?

I had this as my last death wobble. Not just a steering wobble, or kick, but a full on death wobble.
Annoyed as FLICK, as I thought I'd done as much as possible to start fresh for my D1.
New stg damper, panhard bushes, etc, etc even shocker bushes. mine were a bit soft, and causing a bit of stg kick.

Only 6 things I hadn't done to the front suspension were radius bushes, 4 axles and two chassis .. but triple checked and all in good nic .. and checked again for good measure.

Loose steering shaft won't cause death wobble, just a steering kick/wobble, and I even contemplated doing that too.
My laziness in fixing the vac pump oil leak had oil over the RHS str damper rubber bushes, and those were a bit worn too.
Changed to polys .. didnt' fix the death wobble tho.
As the damper was off, I checked it's smoothness .. no worries, full fluid movement .. so had me totally stuffed.

I dunno why, can't explain but something was telling me steering damper.
Won't detail the brand, but if you imagine a red male bovine makes for a close approximation.

Anyhow, got myself a standard LR type(Armstrong brand) damper(I think they're about $40, ie. roughly 1/3rd the price of non std, supposedly heavy duty brand!)
Fixed!
All good.
I estimate the aftermarket stg damper had maybe 40-50K klms on it .. not a lot of rough road usage .. maybe 5K klms.

But to re-iterate again, this death wobble was just like you explained. Had the hippy shakes on the over run, and powering through it settled it before slowing again to stop the residual wobble.
The other specific cause of this particular death wobble for me, was that I had to hit a bump in the road head on, ie. with both wheel at the same time.
For my normal run to work, there's heaps of metal joins in the road type bumps. Over time some become more prominent, and hence more severe.
This was the hard part to kind'a assess. Just when I thought it's not a problem, it then suddenly became a problem again ..
Hit a massive pothole with one wheel .. no probs .. when you get your mindset into a prepare for a death wobble moment.
But over a month or so, I eventually worked out the specific situation that caused my wobble .. being on the over run, roughly 70-80k/h (most of the run to work was 80k/h zone) and hit the bump(or join in the road) dead on.
On the 80k/h bends with joins in the road, where I'd expect the steering damper to make more of a difference .. nothing!! .. hardly even a steering wobble.

The only other way to stop the death wobble was with more potential to cause an accident. That was brake hard down to 60k/h quickly.
Tried the good old back off and try to bring it under control with a gradual slow down, but that made the wobble much more violent.

I also had thought to change the fairly crappy shocks as well in the time I had the issue, but the crappy shocks are more that they're way to hard for a LR suspension .. I prefer softer std or Bilstein type performance suspension.
These shocks were tight, not floaty or bouncy in any way tho, no slack in the travel either.

So I'm curious if you renewed a lot of the front end, did you change the stg damper? if so, LR/Armstrong or thirdparty .. 'supposed' heavy duty?

Originally Posted by AK83

So I'm curious if you renewed a lot of the front end, did you change the stg damper? if so, LR/Armstrong or thirdparty .. 'supposed' heavy duty?

Hmmm. Thanks for the reply.
Yup the steering dampener was basically the only thing i didn't change just recently but that's because i only installed it 12 months ago and its a Terrafirma one.
I am keen to replace it to see if it makes a difference though. Do you have more info on the $40 one you bought - or other brands i should try?