2007 Honda Ridgeline Owner's Manual - Page 252

Automatic transmission Fluid, Rear Differential Fluid 5. If the level is below the lower mark, remove the fill plug, then add the fluid into the hole to bring it to the level between the upper and lower marks. Pour the fluid slowly and carefully so you do not spill any. Clean up any spill immediately; it could damage components in the engine compartment. Always use Honda ATF-Z1 (automatic transmission fluid). If it's not available, you may use a DEXRON III automatic transmission fluid as a temporary replacement. However, continued use can affect the shift quality. Have the transmission flushed and refilled with Honda ATF-Z1 by your dealer as soon as it is convenient. 6. Insert the dipstick all the way back in the transmission. If you are not sure how to add fluid, contact your dealer. 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. This service may be needed more often under certain driving conditions (see page 242 ). Always use Honda VTM-4 Differential Fluid, and have your dealer replace the rear differential fluid. 252