Death wobble riddle

[whitakerb]

Hi Guys, I'm hoping someone can show me my obvious mistake here as it has me, my local dealer, and my local independent scratching our heads.
I have a 2011 90 with 118,000kms on it. I have had a steering shimmy on it now for about 18 months. Initially we thought worn out shocks as the tires were scolloping out at the same time.

Fast forward 18 months and the shimmy is still there between 80-105km/hr. the shimmy is not consistent, sometimes it is very mild and sometimes it is just downright dangerous. In my effort to resolve the issue I have changed/repaired/checked:



Shocks - Konis
Steering dampener - Pedders
Panhard Rod Bushes - Superpro
Upper radius arm bushes - superpro
lower radius arm bushes - genuine
I did a full axle rebuild after the front diff showed signs of failing. Every single bearing and seal was replaced. So were the brake rotors. The swivel pins were preloaded as per the manual. Front diff was changed to Ashcroft ATB.
I have replaced the wheels with new wolf tubeless rims and new tires (I have also had them balanced on the studs instead of the centre bore of the rim)
I have tried 3 other sets of wheel/tire combinations.
We have checked the brake rotor runout with a dial indicator. it is 0.08mm
Wheel alignment is at 1mm toe out



Many of the parts were changed as a matter of cause when the axle was rebuilt as the whole axle was removed and sitting on the bench. The only parts up front that haven't been changed are the track rod ball joints that have done about 50k and feel good, the drag link balljoints which are original but feel fine and the steering box. There is no play in any of the steering linkages and the tail shaft has been removed to eliminate vibrations. The suspension is OEM with 30mm spacers to bring it back up to the correct height with the winch and bullbar.

I am at a point where I'm changing parts of the sake of changing parts. We tried to change the pitman arm balljoint this evening but failed after we broke the puller trying to remove it. Unfortunately this means I'll have to take the dreaded Ford Ranger to away this weekend[bigsad]

Shy of ripping the whole front axle out of another vehicle, I'm at a loss on what to do next. If anyone has any ideas, I'd very much appreciate it.

Cheers

Ben

[JDNSW]

Things not mentioned in your list - you may have already checked these and not noted them.

Swivel preload
Non-standard suspension geometry such as a lift. This changes the caster angle.
Oversize tyres and/or non-standard offset
Steering box or panhard anchor slightly loose on chassis
Loose wheel bearings
Bent or cracked chassis outrigger that the radius arms connect to. Check the welds of the tube the arm goes through.
Wheel balance

[Ancient Mariner]

Firstly I would disregard the manual for swivel preload .With the wheel off the ground and tierods removed there should be some resistance going from lock to lock not flop around like it probably will. With it back together engine going get someone to give the steering a work out while your under with a light checking for any play in bushes or bolts

AM

[PAT303]

Get rid of the super pro panhard bush's,only use original.I had the very same issue you have 10 years ago's when I fitted SP bush's,re-fitted original rubber and haven't had a problem since. Pat

[incisor]

Never had the issue using superpro bushes in panard rods

[donh54]

May sound strange (but it IS a Rover thing!), but I found through trial and error, that my D1 would get real bad wobbles on certain bumps/ripples in the road, if the front tyre pressures were too high. Anything over about 30psi (with those particular tyres - Silverstone AT's IIRC) and it was a constant worry. Doesn't seem to be an issue with the current tyres, but they are passenger case, not Light Truck like the others.

I have also heard of some panhard bushes which only lasted a few thousand k's - possibly the cheaper version of SuperPros, maybe? (Damned Alzheimers!)

[Ancient Mariner]

With 35" muds on 25 neg rims 2" lift and superpro bushes allround I can't find any death wobble maybe I should change to rubber[bigwhistle] With zero caster death wobbles are almost guarenteed , also I would'nt mix rubber with superpro on the same arm

AM

[Vern]

Same, 2 cars fitted with superpro, no issues at all.

[PAT303]

I'm only giving my personal experience,I have SP bush's on the vehicle today,except the panhard rod and it drives fine. Pat

[workingonit]

This is from D1 experiences. Factory standard vehicle. You've probably already covered the following.

Regarding track rod and drag links. Don't simply rely on ball joint to ball joint centre distances (as previous owners or mechanics/tyre shops had). Measure that each ball joint centre is the factory specified distance from the end of the rod itself, then measure overall centre length. Incorrect settings gave scrubbed tyre, worn bearings and constant vibration. When the tyres were new there was no apparent issue, only when the kilometers mounted did the wear become apparent along with vibrations, making you think it must have been a recent adverse event that's caused the problem.

Front shock rubber worn or securing nut not tightened down enough. Push front left and right corners up and down, noting appearance of any gap between rubbers and washers top and bottom of shock. If you find any gap then renew rubbers or tighten up securing nut. With this issue, hitting a small depression or small hole on tarmac resulted in 3 or 4 violent steering wheel jolts before settling again. Direction was not affected and otherwise on smooth tarmac no issues.

Steering damper locked each end with paired standard nuts. Nuts wandered off one end. Constant vibrations but no really violent reactions. Replaced paired nuts with single nylon lock nut each end.

Steering damper failing. Took it off, stretched and compressed, noting inconsistency in mid range. Replaced. Symptom, when driving on tarmac with minor corrugations the steering would vibrate significantly, always in the same stretch of road, smooth tarmac no problem.

Steering box loose on chassis, one bolt missing. Didn't seem to present any issues, only noticed when changing panhard rubbers.

On one vehicle I had two of the above issues, mild vibration with occasional violent steering jolts.

Good luck!

[Phil B]

I had the same issue on my Perentie
New panhard bushes and adjusted the swivel preloads which were both less than specified (14lbs with the tie rods removed)
OEM panhard bushes are the way to go I believe but my wobble was caused by the preloads

[Vern]

Only ever done swivels by feel, never had a drama.
Oem panhard are fine, but you need a press!

[Vern]

Double post

[loanrangie]

Been using poly in the panhard for over 20 years and last for ages, same with Vern i do the pre-loads by feel and set them close to zero.

[PAT303]

I'm not here to start a ****ing contest about bush's,the fact is the vehicle did not have the problem when it left the factory and thousands of live axle LR's have had 2'' lift's without issue and thousands more have been fitted with different offset rims and larger tyres. The violent left/right shake will occur with not enough swivel pre-load or worn/poor pan hard bush's with live axle vehicles,both have been worked on so that's were I'd start first. Pat

[Tins]

Had the same thing. The Panhard rubbers were stuffed. Got a HD Panhard, which fixed it for a bit. Then I found that the bolts mounting the Panhard end to the chassis were a trifle loose. Tightened them, fixed. Came back. Bolts lose again. New bolts and Nylocs. So, I'd check all bolts for correct tension before I went too far anywhere else.

Not saying it's your issue, but it could be.

Saved me having to faff around with preloads. Although that day will come.

[whitakerb]

Thanks for the comments,

We had the drag link and tie rod off last night and the swivels still had some resistance, so I'm confident the preload is still ok. I'm a bit concerned about loading the swivels up any higher than standard after the previous set lasted less than a year. They were installed as per the manual, but ****part don't seam to like hard facing the pins properly. The replacement pins were most certainly genuine and the Britpart ones were thrown in the general direction of the distributor.

The other mechanic at work had a look-see today and he couldn't find a thing.


I've also been running a set of 31" road tires this week to eliminate the 255/85 BFGs that I usually run but the problem is still there. I've learnt 2 things from this.

1. My BFGs are really well balanced.
2. 31" tires on a puma makes it go like stink and returns amazing fuel economy (8-8.5L/100km):twisted:


I have also double checked the wheel alignment this morning and it was 1mm toe out. I have set it to 4mm toe out to see what happens and on a short run it seamed 100 times better than before. I wouldn't have expected such a massive difference by doing this.

I'm off racing this weekend so the work ute is on tow car duties and the Defender is being left in the naughty corner. Hopefully we'll have a result next week. Wish us luck!

124089

[Tank]

Try some "Toe In" instead of Toe Out, Regards Frank.

[rangieman]

Try some "Toe In" instead of Toe Out, Regards Frank.
From memory 1 to 2 mm toe in [wink11]

[Vern]

1 to 2mm toe out chris! 😊

[rangieman]

1 to 2mm toe out chris! 😊
Mmmm knew it was one or the other and i guessed the other[bighmmm]

[MarkM]

Had this on a 'cruiser.
Was wheel bearings' inner race turning on and wearing the stub axle tube.
Changed all the bushes before I found it.

Mark

[Mike57]

Thos is also a problem on the Suzuki Jimny and the Patrol. Usual problem is king pin loading which has been mentioned before. Adding castor will also help but that mainly just adds load to the king pins.

[Phil B]

Thos is also a problem on the Suzuki Jimny and the Patrol. Usual problem is king pin loading which has been mentioned before. Adding castor will also help but that mainly just adds load to the king pins.

King pins on a Land Rover?
They have swivels and the castor is not adjustable.

[Mike57]

Same with the Suzuki. Castor is corrected with offset bushes. I am not familier with the LR fromt axle but it should have king pins like most fixed front axles but I will bow to better judgement. I have D4 and a Jimny and my mate has a Patrol. King pin pretension is a common issue with the jimny.

[Vern]

Landrover swivel hub set up is the same as the suzuki.
Both have swivel hubs and swivel pins (kingpins)

[Ancient Mariner]

Zero caster will certainly promote death wobbles and as mentioned can be altered with bushes. Another more precise method is to clamp the ball to the axle clock to your prefered caster angle scribe the holes and slot in a mill .You also need to drill a locating bolt

AM

[Mike57]

Yes that method will retain full axle travel and allow the original rubber bushes to be used as long as the new holes have adequate edge clearance to maintain integrity.

[POD]

Something I've found that may help to narrow it down; when the panhard rod bushes are the source of a death wobble, the wobble is decreased or eliminated when going around bends, i.e. a gentle sweeping highway bend, it places load one way on the panhard rod and the wobble stops.