Having never experienced this phenomena on any 4 wheeled vehicle in all my driving years even at high speeds, what exactly is this 'Death' Wobble I hear mentioned on the D2 and other vehicles. Oversteer, yes, Understeer, yes, but they are both controllable, well sometimes. I like an over steery vehicle, it's more controllable, more predictable and also more fun to drive.

The only thing I can relate this to is the infamous 'Tank slapper' on a motor bike caused usually by high speeds, dodgy road surfaces or bad luck.

 

 

I had the death wobble.

Scary.

Easy.

Put in Polyurethane bushings.

That is all you need to do.
A few hours at most.

Those go bad because the leaking engine oil all over them degrades and decomposes the rubber.

 

It's usually when there's too much slop in front suspension components, and you hit a bump that causes uncontrollable shaking of the front end. Sometimes to the point where you have to come to a complete stop to end the terrifying ride.

It also happens when a suspension lift is done wrong, throwing the geometry of the components out of whack, even if all components are rock-solid. Usually someone tries to budget lift with too-tall springs or spacers, without lowering the control arms. The diff is turned down, affecting the toe of the wheels, and bumps aren't absorbed correctly. Our trucks aren't usually affected by the modest 1"-3" lifts, but any more and you need the corrected control arms. Another option would be to lower the frame mounts of the control arms.

Jeeps were in the news a little while ago for this, but it doesn't happen in stock form; only when lifted incorrectly and with bigger tires which make it worse. Typical of "mall-crawlers" who only care about how they look, not function.

 

That's not the cause of a tank slapper.
You do not over correct into one.
You also don't under or over steer into it.
That technically is what is happening, quickly and violently, but you can have a tank slapper on a perfectly set bike, and glass smooth straightaway, and speed always ups the odds of it happening.
If you over or under steer a sportbike, or over correct, you're way out of sorts anyway, and a tank slapper is not your immediate concern, not that you would even see it coming.
Tank slap is literal bar to tank, side to side.
A hang on and hope moment, been there. The bike fixes itself, or it doesn't.
Not to be confused with headshake either, which is much, much milder and commom experience, witn no bar to frame contact.
Basically, let the front end get light, and not straighten itself as it settles, and either can happen.
Proper sag really helps, but nothing makes you immune, at any time. Steering dampners help bar feel too, but it's a myth that they prevent tank slap, they don't.

Back to trucks.
Death wobble is from modified suspension, steering and/or frame geomotry. Over size tires also up the chances, especially if not balanced correctly.
Been there too.

 

X1 .......... in my earlier days a few moons ago I used to race bikes and latterly cars at national and international level but I was never a Kevin Schwantz or Wayne Rainey . I have to admit, I had a few 'tank slappers' back then, you either have the space and very large gonads to accelerate through it which works sometimes or it 'spits' you off like a rag doll with some broken bones if unlucky.

This was the motorbike in my hay day along with the 350cc Yam

https://www.google.fr/search?q=yamah...D_gGxwURngHSM:

There is actually a photo of me amongst the many but I'm afraid I cannot declare which one as you'll know exactly who I am.

As for trucks, I always run them near stock and agree with you that messing with suspension causes most problems along with bad set ups, something that's commonplace. Suspension is a fine art of acquired knowledge and calculation as is the steering toe in or out set up. The problem for many is they believe a high lift and big tires is the be all and end all of the story but some years back on this forum I explained how to calculate the suspension 'tuning' but very few seemed too interested and wished to plough their own furrow. Dusty1 the Texan was a past master at 'tuning' suspension and demonstrated his prowess on many occasions on Black Runs/Sections.

 

I’ve seen it happen on 100% stock JK/JKU’s. It’s a PITA!!! I only had the dreaded DW on my 05 Rubicon once and it was due to a tire tossing a weight. I could barely drive it to get to the tire shop!

I’ve never had it with a single LR, but I’ve also never gone taller than 3inches with the lifts.

 

Cool stuff! I Love 2-strokes!
My bike racing was dirt, 250B MX, couple seasons, 20 years ago.
On the street, I never had problems keeping up with the local ameture track guys. There are great roads and mountains to rip through here.
A couple places way out in the cut to stunt too. I always wanted to do a track day, but given the cost of my bikes, gear, parts, Tires!!!, and mounting expenses, I've yet to make it happen.
I had one tank slapper years back on a 94 kawasaki ZX7. About 120mph, 6th gear, crested a hill, front tire lifted a couple inches, when it set down, wow, that was an experience. Violent is all I can call it. The engine died within a couple seconds of the slap starting. Thank you Lord that I was able to hang on. After it settled down and I was back in control, I coasted to under a street light, where I could see that the run switch had flipped to off from the bar to tank impact, lol! Switch to run, started up, back in business!

As for trucks(and bikes)I'm all about the best setup for the application, talking suspension, and always trying to learn something new.
Plan for my 04 D2 is a simple 2" lift with a 31"/32" tire, with steel bumpers and winch, skidplates. So leaning towards a firm spring rate instead of medium to handle the extra weight. Hopefully without making for too harsh of a ride on pavement.

 

 

And this is what it looks like in a LAND ROVER, especially one with swivel pins.
I had this happen in a '92 RRC at 60MPH on a freeway overpass in a left hand turn.
SCARED the out of me!!!!