Death Wobble

[combatcamera]

Death Wobble. OK, so what is it and how does one fix it?

I've got a 1982 ex-MOD Series III 109 FFR LHD and occasionally when I hit a bump in the road or a pothole or something like that the steering wheel will suddenly start jerking violently left to right.

It doesn't happen all the time and when it does I'm usually going in the 30-40 MPH range. It ceases when I slow down to less than 10 MPH.

I'm able to control/ lessen the jerking by tightening my grip on the wheel, but I'd rather just fix it and not have to worry about it.

So, what is it and how do I fix it?

Thanks,

Jon

[badvibes]

Jon-

When was the last time your tires were balanced?

Jeff

[Terrys]

What it is is exactly what you've described. You have six ball joints in your steering linkage; 2 in the link from steering box to relay, two in the link from relay to your right wheel, and two in the draglink from the right wheel to the left wheel. Check each for any play.
The next thing, and very common, is the swivel ball pins. Your top one is fitted with shims, and the pin fits a railco bushing in the swivel ball. Check your preload with a spring scale and remove shims until the preload is tight enough. To do this, you need to disconnect all links, so you may as well figure on doing a complete swivel ball/ housing service.

[I Leak Oil]

Death wobble in a series is when there isnt' enough friction in the system to dampen the natural side to side oscillation of the front wheels. 99 times out of 100 it is due to low swivel pin pre-load. The manual has a section on how to set it correctly. It won't get better, only worse.

[combatcamera]

Jon-

When was the last time your tires were balanced?

Jeff


Jeff,

THanks for the response. It's been awhile since they were balanced, but I don't think this is an out of balance tire thing. It would be great if it were, as that's a relatively easy fix.

Most times there is no wobble, it's just occasionally when I hit a bump or pothole the steering wheel just starts jerking violently from side to side.

Jon

[I Leak Oil]

Probably not a tire balance issue but don't discount it either. As stated earlier it's probably the swivels or TRE's as those are the usual suspects. Could also be from bad wheel bearings, alignment, loose steering box, shot relay....Lot's of fun to be had under there!

[kevkon]

Don't forget a high quality steering damper like OME or Bilstein.

[I Leak Oil]

Adding a steering damper does not solve the underlying problem.

[kevkon]

No it won't solve an underlying problem if one exists and is due to excessive wear or improper adjustment. But a high quality damper will cut down on steering feedback and oscillation.