Indmar 5.7L Vortec Operator's Manual page 66

1. Remove the dipstick and wipe with a clean towel.
2. Insert the dipstick completely (do not screw in
threaded dipstick to check fluid). Remove the dipstick
and read fluid level.
3. Return dipstick after level check. Make sure it is
secured in place.
4. If level is below "ADD" mark, add the proper fluid
until it reaches the full mark. Add fluid through same
tube as you removed the transmission dipstick.
6-16
Figure 6.13 – Walters V-Drive Dipstick Location
INDM-A031
Indmar Marine Engines