Honda 2011 Ridgeline Owner's Manual page 337

Rear Differential Fluid
The rear differential should be
drained and refilled with new fluid
when this service is indicated by a
maintenance message on the
information display or multi-
information display. This service
may be needed more often under
certain driving conditions (see page
324 ).
Rear Differential Fluid, Transfer Assembly Fluid
Always use Honda VTM-4
Differential Fluid, and have your
dealer replace the rear differential
fluid.
2011 Ridgeline
Transfer Assembly Fluid
The transfer assembly should be
drained and refilled with new fluid
when this service is indicated by a
maintenance message on the
information display or multi-
information display.
Always use Hypoid gear oil GL4 or
GL5 with a viscosity of SAE 90 or
80W-90, and have your dealer
replace the transfer assembly fluid.
333