Note: For the Gleason brand final drive, the contact patch is checked on the teeth of the driven gear, for the Klingelnberg brand final drive - on the teeth of the driving gear.
To check, lubricate the working surfaces of the driven gear teeth with a thin layer of lead oxide and check the contact of the working surfaces of the teeth of the driving and driven gears.
Completely assemble the rear axle and install it in place.
Fill the rear axle housing with SAE 90 hypoid oil up to the lower edge of the filler hole.
[This publication was borrowed from an online resource: BMWman.ru]