leftyz

"An incorrect pinion depth and/or backlash makes the gears whine more.. AND may make them last a lot shorter. "

So this issue has been resolved ? may i ask how ?

SpitfireS

^
To leftzy:
Pinion depth and backlash are settings or values that one has to reach or meet when installing a gear set - any gear set - in a diff housing.
If those settings or values are met then there is the correct contact patch between pinion and ring gear as designed by the manufacturer.
This will minimize gear noise and maximize gear life.
(oil playes a role in this too)

It has nothing to do with the ratio, manufacturer of the gears or teeth count.