Checking Transmission Fluid

[Engine Nut]

Here is the correct procedure for checking transmission fluid in the shifting portion of your v-drive or in an in-line transmission. It applies to Indmar V-drive, Velvet-Drive and ZF transmissions. It is best done with the boat in the water

Start the engine and let it come up to operating temperature.

Shift the engine to forward then to neutral then to reverse and back to neutral. Shut the engine off.

Within 30 seconds of engine shutdown, remove the dipstick from the transmission, wipe it clean and place the dipstick in the transmission but don't thread it in. Remove the dipstick and check the fluid level. The level should be between the two marks on the dipstick.

Adjust the fluid level as needed.

Note: Once you have established the appropriate fluid level, it may be beneficial to let the transmission cool down, preferably overnight so all of the fluid can drain back from the cooler and transmission hoses. Pull the dipstick and wipe it off. Reinstall the dipstick but don't thread it in. Remove the dipstick and mark a new "full cold" level on the dipstick so in the future you can check the fluid level without running the engine. Note that the full cold level may be above the original full mark on the dipstick, depending on the transmission cooler location and how much fluid is able to drain back.

[WheelerWake]

Note: Once you have established the appropriate fluid level, it may be beneficial to let the transmission cool down, preferably overnight so all of the fluid can drain back from the cooler and transmission hoses. Pull the dipstick and wipe it off. Reinstall the dipstick but don't thread it in. Remove the dipstick and mark a new "full cold" level on the dipstick so in the future you can check the fluid level without running the engine. Note that the full cold level may be above the original full mark on the dipstick, depending on the transmission cooler location and how much fluid is able to drain back.

This is an excellent tip. I take it one step farther. I take the "hot reading" in the water and then the "cold reading" on the trailer, in my driveway.

[Pistol Pete]

I have always read that you need to run the boat across the water a little ways and then check the level with engine off. ATF expands quite a bit when it heats up.