Heater, problem with top flap

[mtb_tuli]

Wanted to refit my heater, but it is not that easy
The shaft, which operates the top air flap, gets loose, at the gearing end. The first photo shows all shafts in position (is the horizontal shaft position for the closed top flap correct ?), the 2nd photo shows the loose shaft, wen you are pulling at the shaft.
I can see no possibility (a notch for a stop ring or something else) to secure the shaft.
Where am I wrong ?

 

[quattro]

If the splines have worn so there is play when fitted, then I'm sorry to say but they need replacing. Easy job if you can find the spares.

Richard

 

[mtb_tuli]

Will try to drill the shaft and use a small split pin...

 

[Demetris]

Will try to drill the shaft and use a small split pin...

I have done successfully the same in the past.

 

[mikecoombs]

I'd probably start by glueing it into position (with something like JB weld) so you are sure you have the position correct; then pin it. I'd be more inclined to rivet it by using a solid pin and peening the ends over. a split pin will leave slop in it which with a worn shaft will just wear everything further till it breaks the pin. Check that the levers have some free play beyond their in car stops. if the shaft is stopping the level that will wear the splines. The lever, being the driving member, needs to be where the movement stops are although it is a fine thing as you want the flaps to shut fully.