Cannondale ATV Owner's Manual page 94

(1)
1. Transmission oil window
NOTE :
The transmission oil level within the crankcase should
be visible in the window. Maintain the oil level between
the "LOW" and "HIGH" as indicated in the illustration
above.
92
3. To add, reinstall the check bolt and pour the specified
transmission oil slowly and in small amounts using a
clean funnel. Recheck the level.
HIGH
OK
LOW
Transmission oil filler hole