A simple question I hope.

Why can I not put the car into first gear (especially when its cold) when its moving at say 5 mph, and yet if I put it into gear when stationary I can drive at 30-40 ish in first if I want?

Driving in traffic is a bit of a pain when the car has been standing at work all day untill things warm up a bit.

Please don't say they all do that they may well do - but WHY?

 

It is very difficult to select first gear while on the move because you ask the gearbox to syncronise two axis which have a large angular velocity difference (perhaps even more than 3000rpm). It is much easier to double declutch to minimise this difference. This way downshifts are smoother and the syncromesh is not stressed as much.

It is not just the Subaru gearbox that does this, "all gearboxes do that sir" .

 

Gets much worse if you've fitted a quick shift (lever only type) without first dressing the surround metalwork to ensure no contact

Richard