Hi Dave,
The column is designed to telescope in the event of an accident. The upper column is tubular with the lower column sliding inside. There is a kind of
D-clamp just below the bottom of the outer column - stick your head beneath the dash and wiggle the wheel, you'll see the clamp rotating.
Now you've found the clamp you'll see that there are 2 bolt heads on one side, with an allen screw and locknut on the opposite side in the centre. The
bolts are intended to hold the clamp tight on the upper column, the allen screw adjusts the tension on the lower column. The wording in the manual says
"hand tight" or something equally enigmatic. Adjust so that it doesn't telescope unwantedly and you won't be far wrong. Don't forget to tighten the
locknut,
Cheers,
Bill.
http://www.rarebits4classsics.co.uk