Hi all, having an issue where when the car has warm up. It is hard to go into first gear to take off. I have to push it/force it into gear. It also always grinds into reverse when warm. When car is off it shifts into gear fine. Standard 4 speed box with a heavy duty clutch put in almost 2 years ago. Has a standard shifter and is a 2 litre car. Would the problem be the shifter? Or am i looking at a gearbox out job? Thank you

The synchros are getting worn..
Try this
Put the car in second gear and then first gear especially when cold and just started up, the synchros need to slow down a tad. Also it might be worthwhile changing gear oil if it's old.
I was told by a UK guy that going 30% trans fluid and 70% hypoid really helps, I done this to my type 9 5sp box when installed back in 2001 , never a problem.