I replaced the noisy gearbox on my 97 Polo (petrol) last night with another old one that wasn't as bad. At least now I can get all the gears and 4th isn't another neutral.

Before I put the gearbox in I checked the oil level by removing an electrical switch on the side of the box, just below the hex plug, and seeing if the oil was at the level of the switch. It wasn't so I added another 300ml. 60ks later the gearbox started to jump out of 5th gear and kept doing so every 5 min. The same thing happened to my old box when I topped up the oil and it got progessively worse until I couldn't use 5th at all because it jumped out of gear all the time. I didn't worry as I get better fuel economy running in 4th (5.9 l/100k) and it goes up hills much better. Am I overfilling the gearbox and exactly how do I check that it has enough oil?

I also need to replace the windscreen. Is the Polo screen bonded in or can I do the old string around the rubber seal trick and install it myself?

Cheers

Paul