highway death wobble

[steaktaco]

1998 Discovery. Symptom: At 60+ MPH, I hit a bump and there is a massive uncontrollable wobble with shaking steering wheel. Goes away with slowing below 50 mph. I have swapped the wheels and checked the steering components for anything obvious and found nothing. What is the prime suspect here? Alignment is good. Thanks.

[Savannah Buzz]

Search for Death Wobble. Can change your pucker factor when exiting downhill ramp from expressway... There have posts within last two weeks about a particular bolt on the steering column.

1. What it is not - the steering damper. That keeps your hand from being broken when you hit a big rock on the trail. A new steering damper might mask DW, but it does not fix it.

2. Can be a mix of parts, pan hard bushing, a bolt on the steering column inside the engine bay, ball joints, sticking calipers, warped rotors (sometimes the combination of things makes the oscillation trigger, or make it seem worse)

[Spike555]

This is one of the reasons why we have the tech section.
Read through these links and then take action accordingly.
If you have any more questions give us a shout.

Do you have death wobble? Please read!

How To Adjust Your Swivel Pin Preload

[antichrist]

You should be methodical in your diagnosis.
I posted this in another thread about death wobble in November.

With the wheels on the ground have someone move the steering wheel back and forth.
While they are doing that start with the steering wheel to steering gearbox shaft and find where there is movement on the steering wheel side of a connection and none, or less, on the road wheel side of the connection.

It could be (probably is) any combination of:

• Steering shaft u-joint loose on shaft or steering gearbox (least likely)
• Internal play in steering gearbox (adjusting nut on top)
• Loose pitman arm
• Loose steering box mounting bolts (or any other loose bolts in the steering system)
• Ball joints
• Panhard rod fixings/bushings (Not directly connected to steering, but centralizes axle with chassis to prevent relative side to side movement)
• Loose wheel bearings

Other worn suspension bushings will contribute, as will worn tires.
Check everything in the list and make sure they are all up to par. If the problem persists then you need to adjust the swivel pin preload. I'd go for a rebuild rather than just removing shims which is nearly always only a short term fix anyway.