Flying wipers

[htfx19]

My windshield wipers have a tendency to fly off. Once in a while, with no particular pattern a wiper comes off its shaft ans fly off, arm and all.
This was true in my late GreenX too.
I got a replacement set of shafts, mechanism and all from Papa Tony (remember) and the wiper arms keep flying. Needless to say how annoying it is, in midst traffic, on a highway, and it's always during rain.
I am about to drill and tap M5 into the shaft and screw those arms on.
What would you say?

Enjoy -

 

[budgetzagato]

Huh!

Mine have always seemed loose but, even though I regularly drive my car in the rain, they have never flown away. It's not the most confidence-building system, simply pressed on and held by a spring tab against the tapered splines. I think your fix is a good idea. Probably want a stainless machine screw, M5x1.0?

 

[Mickey Dale]

I wrapped a layer (or 4) of PTFE tape to help it grip better. Been fine since but feels like a bodge job! These cars, you gotta love constantly keeping up with a world of niggling faults! Luckily, I do love it!

 

[htfx19]

Luckily

Luckily they never realy flew off, the arm + wiper dropped off and stayed on the front hood even when I was going 80 Km/h.
At times the two of them dropped , both laying on the hood till I was able to stop (and get out in the rain, push them back on, drive and constantly praying).
Never a dull moment...

Enjoy -