Toyota Rav 2004/5 2.0 Petrol Manual

[paul777]

I have a whining noise at around 40-60 mph. It’s only just started and can be heard all the time now around those speeds. On deceleration it goes. Some people on here say it could be alternator, could this be true and is there a way of checking this or the mouse out please 

[FROSTYBALLS]

Moved to the Rav4 club

[gjnorthall]

Is it the same noise in 4th or 5th gear?  When was the rear differential oil last replaced?

[paul777]

It’s mainly when you get to around 50-60 and then it’s constant .....Sorry about my ignorance but where do you put the read diff oil please . Thank you 

[Grumpy stumpy]

Possibly 5th gear, common problem , see if noise happens in 4th which  would rule that out .