Angle Gear, Diff & Transfer Case
Angle gear is a bevel gear is a transfer case. Different names for the same 90 degree gearbox that bolts to the sideways oriented transmission and turns the power flow 90 degrees so the driveshaft points to the rear axle with the AWD control system on the front of rear differential.
The angle gear units do not have gear parts available from Volvo as spare parts. The bearings and seals are serviced but not the actual gears. One of the gears is mounted to a spindle using a specialized adhesive and is pressed on. The press fit makes that spindle not usable to properly retain a new gear pressed onto it.