Join Date: Mar 2007
Location: Bridgend South Wales
Car: Rover 620ti, 2x 1996 MGF, 4x MG TF, Mazda Bongo, 2x 1999 MGF, 1972 Ford Cortina Mk3 Citroen Picasso
The original chrome ones do tend to come off as though they are screwed on even though there is no thread on it, however; that may just be because as you turn its instinct to pull away from the lever. the plastic ones are tight and need twisting and pulling.
I think (as not dismantled one) the shaft the button fits onto is a slightly wider diameter than the hole in the actual button, hence a tight fit. My stainless steel button just drops onto the shaft I was going to put a bit of glue on it, but it's not fallen off when driving s never bothered.