Tdi dash vent knob removal?

Hi, got a 91 plate tdi and looking at taking the dash vent knobs off (old style saying vents on).

Are they suppose to screw off, don't want to be asking the hole lower dash off . I had a go but didn't want to be too heavy handed? Got some nice aluminium ones coming soon.

Any help be great!

Don't you have to take of the nuts from the back of the vent flap? or are you talking about the ones at the sides of the clocks?

If you mean just the actual knobs of the bulkhead vents, then looking at the mech they should just screw off, but I tried on mine and they feel like they don't won't to. I may have another go today and use a bit more force.

Well, there's no way mine are coming off, they seem to be one piece.

There doesn't seem to be a thread on my mech like the one here.

Looks like mine is one of these, so will have to change the whole unit...not cheap!

oh that's a shame, I took a punt and got some as they said will fit all defenders, might it be they are just on super hard and need a good whack and pull to get off

I have the same problem, actually I snapped a knob as I had to really crank them shut. It looks like it is bonded with some sort of epoxy and not a replaceable item.

The vent control does not mention the knob, so assume it is a moulded part.

Here is the parts cat for reference: