hi all, few weeks ago I went for a short drive offroad, when I used the low range for the first time in years. Since then I hear a whining noise coming from the transfer case while driving. It starts after the car gets to temperature (cold it´s silent) and stops only after the engine ist turned off (with a sound of few revelations like a flywheel or something). Does anybody have any idea? I mean the chain of the transfer case has always been in motion, independent of high or low range, it´s not that it has been activated by my using the low range and is now behaving like in an old bicycle

"....and stops only after the engine is turned off"

Are you saying that the noise is still present when the vehicle is stationary?

Phil

Now that you ask…strange - it is actually most noticeable when the car is standing (e.g. at traffic lights), cause while driving above 30 mph it is covered by other driving noise.

If it’s happening when the car is stationary then it’s not the transfer box that’s causing it.

Does the noise change if you put the car into neutral?

My guess is it’s an idler pulley or something that’s got wet and muddy whilst off reading. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

ok, I see your point regarding the transfer case - it does not move when in neutral. But I also don´t think its the idler pulley - the noise is not as hearable from the motor bay as it is near to the gear box underneath the car (or even close to the front wheels). It would rather get louder in the motorbay if it would be one of the pulley or the alternator, wouldn´t it?

Have you tried moving between high and low ratio a few times in case something that did not disengage fully the first time then does so? Only Range Rovers since 1988

@CS: actually I haven´t but considering what dhallworth wrote: the transfer case should be quiet when stationary - otherwise the driveshaft would also be moving towards the wheels - so the clutch in the gearbox already disconnects the movement towards transfer case, I guess. So now I´m looking for anything that revs always when the engine is on, independent of the movement of the car and is located somewhere near the gearbox and is somehow dependent on the temperature (as it does not whine while still cold). tricky...