I have a gearbox that works well but is noisey in 1st,2nd and 3rd but is quiet in 4th.
Hi,
First, second, and third, (and reverse) all involve the layshaft. Top gear does not .... it just joins two shafts together - they run in line with each other. My first suggestion is that you check the gearbox oil level and viscosity. Then start looking for another gear box.
My S2 (with TD engine) was noisy in lower gears. Then the layshaft broke. I could drive home in top gear using LO to pull away. Any other gear just screeched as the teeth brushed past each other.
Changing your transfer gear ratio with not stop your gearbox being noisy.
602