VY2SS diff whine

[VT2SS]

Had my Diff ratio changed to 3:9's on my VY SS commodore. I am getting a whining noise from about 70 to 90 kph. They have changed the crown and pinion 4 times now, and each time it still has the same noise, and after the most recent change the noise sounded louder than ever before.

Has anyone experienced a similiar noise after changing ratios? The dealer doesnt seem to know what to do, has anyone got any ideas?

[HRT Stroker]

I was told this is relatively common with the 3.9 ratio by diff shops in Adelaide.......maybe go 3.73 if its auto or 4:11 for m6!

[snowySS]

My 3.91s have just started to whine as well. Only noticed after a run at WSID. I thought it may have been caused by a lack of mechanical sympathy.
I am getting it looked at next week.

[Speedy Gonzales]

Yep I got whine after changing to 3.46, might have to change all bearings next time and also, the gears wear in a certain way, each car is different so a slight thou out can cause a whine.

[BOSS290]

Do you know if the crown wheel only is gettin changed when you go for the 3.9:1 or the pinion is getting removed as well?