1999 Honda CR-V Owner's Manual - Page 201

Rear Differential Fluid (4WD models only ) FILLER BOLT Correct level If CVT Fluid is not available, you may use Honda Premium Formula Automatic Transmission Fluid (ATF) or a quality DEXRON® III ATF as a temporary replacement. However, continued use can cause noise, vibration and performance problems. Have the differential drained and refilled with Honda CVT Fluid as soon as it is convenient. The rear differential should be drained and refilled with new fluid according to the time and distance recommendations in the maintenance schedule. Check the fluid level with the rear differential at normal operating temperature and the vehicle sitting on level ground. Remove the differential fluid filler bolt and washer and carefully feel inside the bolt hole with your finger. The fluid level should be up to the edge of the bolt hole. If it is not, slowly add Genuine Honda CVT Fluid until it starts to run out of the hole. Reinstall the filler bolt and tighten it securely. Maintenance