KAM offers a range of alternative ratio crown wheel and pinion gear sets specifically designed for Military, commercial and competition applications. The optimum final drive ratio can be selected to accommodate increased tyre diameter, up rated engine performance and vehicle application.
The strength increases are measured by using the standard 3.54 ratio as a datum and calculating input torque produced by the engine power and output torque
produced by the feedback into the differential from traction obtained.
Up to 25% gearing reduction with up to 70% increase in strength is possible with KAM lower ratio crown wheels and pinions. 3.54: 1 is the standard ratio on all Land Rover Defenders, Discoverys and Range Rover Classics. Lower ratios of 3.8 ,4.1 and 4.75 are available. The effect of these lower ratios can be seen on the chart.2.83 ratio is higher giving 28% increases in overall gearing. It has the effect of either reducing the engine revs and / or increasing overall road speed. This is generally suited to high-speed roadwork and vehicles that have had engines modifications.
Land Rover fit the same differential assembly front and rear, as a result the front differential rotates in the opposite direction to the rear with the driving force being applied to the back of the gear teeth. KAM produce ring and pinion sets for the front differential assembly that are ‘reverse cut’ which ensure the force is applied to the stronger/correct side of the gear teeth.
NB: For clarification all 2002 on defenders have a short nose fitted to the rear and the long nose fitted to the front
KAM539 ratio 3.8 90/D1/D2/RRC up to 2002 REAR
* We would advise that for ease of fitment that you purchase a 539706 Pinion Head bearing with this Crown Wheel and Pinion set.