You need some sort of gearing to match the speed of the motor (higher) to the speed of the axle/wheels (lower). Depending on your choice of motor, it may not need multiple ratios, so you may not need a transmission like the original, but you need something.Is it feasible to reduce weight by getting rid of the gearbox...?
If you mount the motor at the axle, you don't have a prop shaft. The details from there depend on the vehicle - "Range Rover" covers four generations of vehicle with completely different designs for the early (classic and P38A) and later (L322 and L405) generations, and "HSE" is just a trim level, not a mechanical description. That's assuming it's not a Sport, Evoque, or Velar... which are different again.Is it feasible to reduce weight by getting rid of the ... prop shaft, rear axle & differential?
If you use one motor to drive the rear axle, then you need a differential to split the power between left and right wheels, allowing them to turn at different speeds. If a lighter differential were practical, it would have been used.I would use two motors, one for the rear & one for the front & one for the rear.
Is there a lighter alternative to the heavy standard rear differential?