I've just seen your thread and see that you've referenced my steering lock 'fix' from a couple years back.

Let me give you the update.

That brand new steering lock that I purchased is still sitting in the draw unused. I figured before I would spend money at the dealers I'd have a sneaky look inside the old unit.

So I decided to open up my "non-serviceable" steering lock and have a look inside it. This took some drilling out of the case to get it open but I figured it wasn't working anyhow.....

Inside it is an electric motor and worm drive with a small limit switch that gets sticky, hence the bumping and thumping of the steering column (in my case I kept a large brass hammering dolly in the door pocket to hit the lock with. Bottom column cover permanently removed)

I took the whole lock apart on the bench and worked the limit switch a bazillion times with my finger till I was happy it moved freely and then put it all back together with a judicious screw or two holding the case lid back on and reinstalled in the car. It has now not given any trouble for the past 2 years.

Hope this helps!