The replacement hypoid differential which has been designed with a vacuum diff lock, will fit many vehicles such as, Range Rover, L/R discovery, Land Rover, Toyota Pickup (USA market) Toyota Hilux & Hiace (VAN), Toyota Fourunner and Toyota Bunderra. The differential comes in two (2) different Banjo Housing Stud Patterns for fitment to either Toyota or rover vehicles Banjo Housing Stud Pattern. Because of the Toyota wide range of gear ratio's i.e.3.42, 3.54, 3.72, 3.9, 4.1, 4.3, 4.375, 4.56, 4.71, 4.875, 5.28 & 5.71 being readily available world-wide many rover owners can now lower the vehicles differential ratio when larger wheels are fitted, which is common in snow climate countries and also when the vehicle is being used for off-road & rally competition. The advantages of using this Hypoid Differential in Rover 4 wheel drives is the much stronger crown wheel & pinion gear sets, that are used, the Hypoid 3.54 ratio gear set has a 21mm larger pinion head and the 4.71 ratio gear set is 14mm larger at the pinion head compared to what the standard rover is. The Hypoid Off Set is 1-1/4" which creates a greater tooth load surface area compared to the Centreline driven spiral bevel gear set. Also the carrier ( Hemisphere) uses 4 pinion gears to drive the 2 axle gears, being able to use either 24 or 30 Splined axles with the Hypoid Differential makes this rover replacement differential extremely strong and reliable. The engine manifold vacuum, (petrol engines) or the alternator vacuum pump, (diesels engines) is utilised through a 3 port switch mounted in the drivers cabin, when operated the switch selects the diff lock. The diff can be locked while the vehicle is in motion, so long as it is straight ahead driving. A vacuum water trap fits under the bonnet to safe-guard the engine. The "Rover" Hypoid Case can be supplied separately so that the standard Toyota carriers, LSD, ARB or Detroit locker carriers, can be used. The Hypoid "Rover" replacement differential has been actively involved world-wide in competition work since 1992 without any reported failures. The Locking Hjypoid Differential Case has been designed with a machined flat area on the right hand side of the case, where a vacuum block is fitted. When the driver selects diff lock, the diaphragm in the vacuum block moves a selector rod through the Hypoid case which in turn causes a slip ring to engage the locking ring over one axle gear, locking the axle gear to the carrier. The spring load selector push rod unlocks the differential once the cabin diff lock switch is returned for normal diff use. Except for running the vacuum line from the cabin to the vacuum block, there is no alteration to the banjo housing to fit this diff lock, unlike that of other design's requirements. The standard tail shaft fits the Hypoid pinion flange.