Hi Paul, gald to see you're still running the golf.
I had exactly the same 2nd gear problem with my first 16v, 2nd gear crunch when cold, drive a mile and its fine. Common on golfs and the box can last for ages with it like that, just ease it in real slow for the first mile or so. The difficulty getting into fifth when warm I had on my second 16v, it was wear in the lower linkage bush. This is a large orange bush (when cleaned up) and the main linkage rod from the bottom of the gearstick runs through it, its right next to the exhaust down pipe and when it gets warm it goes a bit soft so you don't quite the travel in the linkage when you push it across to fifth. Its worth renewing all the nylon linkage parts, the kit is cheap, it just a bit of a pig to fit but when done it makes the shift 'feel' like new. It won't cure 2nd gear though. The special gearbox oil mentioned is made by 'Redline', they do many types, I can't remember the particular one, ('MTL' or something like that). I tried using it in my gearbox, there was a small improvement in 2nd but it didn't fix it but what did happen is because its a thinner oil it set the driveshaft seals off leaking a bit. I've heard that many experience this (its vvvv expensive as well). As mentioned you could try adjusting the linkage on the spline to cure the 5th gear problem but usually if you then get 5th OK you have trouble getting reverse and sometimes you get first instead
. The fact that its happening when warm points to knackered bushes. Hope this is helpful. J
