Hello,
A small but annoying problem on my '69 Firebird - I can't move the trip milage. Should it rotate clockwise? there's a sign on speedo saying don't pull out. Mine did rotate, but now seems stuck. I'm worried about using too much force. Maybe it's just decided to pack up.
You will get this .The trip gear box can give up the ghost. repair is not cheap .Good luck !
After a bit more of fiddling with knob , back then forwards, it suddenly worked and went to 000,00.
I don't trust it for future, but I've always got reserve tap.
Try getting yourself a new trip knob. I find the extended ones work best and don't fowl the rubber binnacle. Pull the old one out and the new one, should push straight in, might need a little twist to find its home position