I'm finding my td5 90 a bit noisy on long journeys. I've looked at the GKN overdrive but its expensive and basically just adds a sixth gear. Ashcroft transmissions offer a new transfer box which I think increases everyhigh box gear by 15%. Very similiar to the Discovery box. Also its cheaper but im afraid the de-tuned Defender engine might not have the guts to pull it. Any advice would be appreciated, particularly from anyone who has fitted the 1.222 gears.
Thanks,
Bob