Intermittent steering vibration

My disco 2 has an intermittent vibration through the syeering column which is intense at times, but I can drive for 30 or 40 miles and it behaves perfectly then out of the blue the vibration starts. Fitting a new steering damper this weekend but is there anything else I should check at the same time. Many thanks.

Does the vibration pop up out of the blue or after hitting a bump in the road?

Edit: Perhaps in asking about this problem you may be better served if you post of the issue in the Disc section of the forum.

Wheel balance out
Steering damper
Track rod ends
Drag link ends
Drop arm ball joint
Panhard rod bushes
Radius arm bushes
Etc etc

Get under it with a prybar and have a bloody good lever on everything. Could be play in a few joints adding up.

Check YouTube for 'death wobble'

Welcome to the forum

Thank you very much for the greeting I appreciate it,. lincs poacher