rear diff whine

[bilko0795]

Hi guys i purchased my first S2 on saturday when i took it for a test drive for about 10 miles there was no noise coming from the back of the car, as i sat in the back while the wife drove. Then on the way home from Aberdeen back to south wales i managed to press the diff control button and from then on it started to make a whining sound faint at first but as you can imagine by the time i got home 633 miles later it,s now quite loud, because the button did not stay down and no light came on and after pressing it again i assume it did not engage the diff lock. So i need your advice to wether the diff did engage and the switch is faulty or the diff is knackred oh i noticed some oil on the bottom of the diff housing but because the woman said the car rear subframe had been wax oiled i took it to be that. So any info would be most welcome.

Thanks

Ray.

[A80Avant]

the diff disangages after aprox 25kms/h. So even if you press the button, it automatically switches off once you drive more than that.

However the whine, could it be low on lubrication? or wear? They are supposed to be bullet proof, if looked after!

[Error404]

you would have known if the diff was locked on, the car would have been pretty unpleasant to drive, also the tyres would probably be pretty knackered after 600 miles! As Vas said, likely its low on oil - top it up. Needs to be filled level with the bottom of the filler plug hole.

If you can undo the drain plug, worth draining and changing the fluid. Also likely your output flange seals need replacing - common problem well documented on the forum