Super Death Wobble

[disco_al]

Here's a head scratcher for everyone. Friend of mine has got a 1994 Defender 90 300 tdi. At 47 mph (don't know how he knows it's 47mph) there is a slight shake from the steering wheel, bit like out of balance wheels.

But, when you hit a pothole at anything from 30mph upwards, you get the "death wobble" from hell through the whole truck. Before i hear cries of swivel proloads - the wheel bearings have been changed, top and bottom swivel bearings replaced, HD steering bars on it, with excellent track rod ends, terrafirma shocks and springs, approx 10 months old, polybushed radius arms (Bearmach ones). Tyres are like new (BFG Mud Terrains - 235/85/16), wheels have been balanced. Front prop is currently removed due to a UJ needing to be changed, and also the diff pinion input bearing needs looking at as there is a bit too much play, causing vibration through the driveline when accelerating.
Sooooo, what is the problem causing the "death wobble" and the speed related steering wobble??? I've had my head out the window (passenger side) when it has happened, and you can see the wheel wobbling as if it's about to fall off

[mat2495]

have you checked the panhard rod bushes? they can give 'death wobble' after hitting a pothole symptoms when worn out, also worth checking that the bolts for them are a good fit in the chassis and axle brackets as the holes can sometimes oval

Matt

[De Ranged]

Can be caused by caster loss from a suspension lift when using radius arms, any wear in suspension bushings or steering joints is accentuated

I have had one truck in (safari) that we ended up doing all the steering joints and new radius arm bushes and panhard bushes to beat it

[disco_al]

forgot to mention it's on castor corrected arms as well. panhard rod bushes are next in line, just waiting on delivery

[duncmc]

I am just going through the same process with mine. The panhard rod bushes will be done at the weekend. I hadn't though of checking the bolts in the axle brackets. One to look out for, thanks.

[Maverik]

Power steering box is FUBAR.

When I was trying to diagnose my issue (to light steering) - I cam across more than once reference to the death wobble where it was found to be down to wear of one of the gears in the PAS box which effectively caused the hydraulic feedback controller (torsion bar) to not self centre any more and it overshoots - which translates to a power assisted oscillation of the steering, I'll see if I can hunt down the thread.

It sounds like you've sorted everything else it could be. time to bite the bullet.

Mav

[jbs]

Yep, and go direct to Adwest and get a new one for less the price of a rebuilt one from paddocks et-al, I've had mine on my 90 for well over a year and sof far its been as good as gold

John

[Maverik]

Yep, and go direct to Adwest and get a new one for less the price of a rebuilt one from paddocks et-al, I've had mine on my 90 for well over a year and sof far its been as good as gold

John

Yeah I think this is the best option too, Adfwest is now Megal Engineering contact this lassie megan.broadhurst@magal.co.uk, she'll sort you out. The 90 is running a direct purchase one now for 2yrs and its tight as a button, and juts replaced the box on the 110 also with a direct sales one and nice feeling to have a brand new PAS at the wheel, can change the feeling of the whole truck.

Mav

[Tanuki]

Check shock-absorbers too: a death-wobble on my 90 was cured totally by replacing the original, 90,000-mile-old shock-absorbers with a set of nice shiny yellow gas-pressurised Bilsteins.

[zardos]

Check the panard rod mount on the axle, as quite often gets made oval.
Just weld a washer on the front to make the whole round again.

[o_teunico]

A friend of mine also has had "death whoble" problems. 285/75R16 Mud Plugga where too big to be used with stock 3.54 diffs, so he swapped to 205R16 A/T tyres, and that tyre change caused the problema at 40-45mph. Now he is using again the big mud pluggas and "death whoble" has dissapeared. Only fault on car that we see is some play at wheel bearings.

EDIT: forgot to mention that car is a Disco 300

[miketomcat]

Inverted anti roll bar mine was jammed against the spring seat causing rear steering.

Mike

[Aragorn]

Who fitted the bearings and set the swivel preload? Have you seen, with your own eyes, that its set correctly? Or has some garage jammed in some carp bearings with the original shims and claimed they've "replaced" them....

If you can physically SEE the wheel wobbling around, it has to be something at the end of the axle thats causing it IMO.

Panhard rod or shocks might allow the whole axle to move around in an uncontrolled manner, but they arent going to cause the wheel to wobble around like its about to fall off...

[disco_al]

Who fitted the bearings and set the swivel preload? Have you seen, with your own eyes, that its set correctly?

me and yes they are set as per spec. we rebuilt both sides, top and bottom along with wheel bearings a few weeks ago to try and cure it, still no change.

[Daan]

Check the panard rod mount on the axle, as quite often gets made oval.

Just weld a washer on the front to make the whole round again.

That.

Also check also you tracking, as tow out could accelerate the problem.

Daan

[Maverik]

Lots of advice here, be systematic and work on/replace the items that are easiest and cheapest first... simples...

[Diablo]

I had very similar symptoms a couple of years back. It was caused by shagged panhard rod bushes, ultimately caused by too low a preload on one of the swivels.

Perhaps you've cured the preload now, but not the bushes?

[JeffR]

Try levering the chassis end of the pan hard rod side to side in its bracket. I spent bloody months trying to sort out a death wobble and found ithat the inner metal sleeve of the bush was about 5mm too short, a washer cured it.

[Therugbydisco]

Hi guys, 

So I have looked in to this as it exists on my disco 1 300tdi and it seems there are a few simple things to try before we go in to spending money as I've looked all over and this seem to be the main fixes in the following order. I hope this helps

1. Check everything is nice and tight underneath so steering arms, axle bolts, panhard rod, wheels e.t.c.

2. Swap front wheels to rear and vice versa, if this fixes it the wheels need balancing. 

3. Check the bushes (pahard rod, radius arms e.t.c) as they may be worn. 

4. If you have lift double check you have castor corrected radius arms so for front if its 2-3" lift u need 3 degree, if it 4" or more u want 6 degree. 

5. Possibly axle related. 

6. Past that point there doesnt seem to be much in the way of what you can do to fix it as everything from what I have listed seems to cure most people's problems. So I advise you to take it too a lr specialist past that point and if they don't know well good luck and let me know the fix as it might be Fubar. 

 

If this helped you can see what I have done to my truck on my insta therugbydisco

Edited December 15, 2020 by Therugbydisco
Error in description

[landroversforever]

3 hours ago, Therugbydisco said:

Hi guys, 

So I have looked in to this as it exists on my disco 1 300tdi and it seems there are a few simple things to try before we go in to spending money as I've looked all over and this seem to be the main fixes in the following order. I hope this helps

1. Check everything is nice and tight underneath so steering arms, axle bolts, panhard rod, wheels e.t.c.

2. Swap front wheels to rear and vice versa, if this fixes it the wheels need balancing. 

3. Check the bushes (pahard rod, radius arms e.t.c) as they may be worn. 

4. If you have lift double check you have castor corrected radius arms so for front if its 2-3" lift u need 3 degree, if it 4" or more u want 6 degree. 

5. Possibly axle related. 

6. Past that point there doesnt seem to be much in the way of what you can do to fix it as everything from what I have listed seems to cure most people's problems. So I advise you to take it too a lr specialist past that point and if they don't know well good luck and let me know the fix as it might be Fubar. 

 

If this helped you can see what I have done to my truck on my insta therugbydisco

FYI the original poster hasn’t been on the forum for 4 years. 

[miketomcat]

Track rod ends/steering damper and swivel bearings/preload. The only other wild card is wheel bearings and the rear axle bushes and joints etc.

Mike

[Therugbydisco]

1 hour ago, landroversforever said:

FYI the original poster hasn’t been on the forum for 4 years. 

Yes, but for anyone looking in to it this still comes up so I thought it may help someone. 

[jeremy996]

Being systematic is key, starting with the cheaper stuff. First thing to try is make sure the steering box is properly tight, not by looking at it but by giving it a tweak with a pry bar. Mine had a very slight wobble, which when provoked by a pothole and 45mph+ led to a very scary death wobble. Everything else was OK at the time. Since then, the last experience was after a numpty, (me!), had set up the preload badly. I'm better at it now. 

[RRC200Tdi]

On 12/15/2020 at 3:11 AM, Therugbydisco said:

Hi guys, 

So I have looked in to this as it exists on my disco 1 300tdi and it seems there are a few simple things to try before we go in to spending money as I've looked all over and this seem to be the main fixes in the following order. I hope this helps

1. Check everything is nice and tight underneath so steering arms, axle bolts, panhard rod, wheels e.t.c.

2. Swap front wheels to rear and vice versa, if this fixes it the wheels need balancing. 

3. Check the bushes (pahard rod, radius arms e.t.c) as they may be worn. 

4. If you have lift double check you have castor corrected radius arms so for front if its 2-3" lift u need 3 degree, if it 4" or more u want 6 degree. 

5. Possibly axle related. 

6. Past that point there doesnt seem to be much in the way of what you can do to fix it as everything from what I have listed seems to cure most people's problems. So I advise you to take it too a lr specialist past that point and if they don't know well good luck and let me know the fix as it might be Fubar. 

 

If this helped you can see what I have done to my truck on my insta therugbydisco

Nice post, thank you for this helpful information. I have one question: wouldn't caster-corrected swivel-ball housings be a better option than a correction in the radius arms? I would be concerned about the increase in the pinion angle on the front differential leading to binding and premature failure on the front driveshaft u-joints. I only have a 2" lift, but have been hesitant to change the radius arms for this reason. Currently, I am fortunate in that I have no issues with death wobble.

[Mo Murphy]

2 hours ago, RRC200Tdi said:

Nice post, thank you for this helpful information. I have one question: wouldn't caster-corrected swivel-ball housings be a better option than a correction in the radius arms? I would be concerned about the increase in the pinion angle on the front differential leading to binding and premature failure on the front driveshaft u-joints. I only have a 2" lift, but have been hesitant to change the radius arms for this reason. Currently, I am fortunate in that I have no issues with death wobble.

Yes.

Mo