ED EVANS
• General workshop tools, vehicle lift, pit or secure ramps, transmission jack and lifting jig.
TIME
6 HOURS
COST
SEE PANEL
DIFFICULTY RATING
This 1989 Ninety, and most early Defenders, have a 1.4:1 ratio transfer box, which is fine for general and off-road use and towing. But at speeds above 55-60 mph the high revving engine makes noise levels uncomfortable for long journeys, and it isn’t good for the engine.
This can be sorted by increasing the vehicle’s overall gearing so that, for a given speed, the engine revs will be lower, producing less noise and vibration and a more relaxing drive. In theory, fuel consumption should drop when cruising at normal speeds but, in practice, if the higher gearing is used to drive faster, the fuel will…