Changing Transmission Fluid (99 air nautique GT40)

You want to use the dipstick hole for both the removal of the old, and the replacing with new.

1.) Get yourself one of these pumps from Nautiqueparts.com or other. They also make cordless drill powered models. You don't have to get this exact pump, but they key is the narrow tube on the sucking side. You can't get a fat tube down into the tranny:


2.) If you can, secure a helper. This person doesn't have to be mechanically inclined, but they have to be able to pump a pumper, and keep the outlet hose going into a receptacle without spraying used tranny fluid all over your carpet. You can do it by yourself but it can be a hassle.

3.) Get two equally sided receptacles. Clear plastic OJ containers or clear windshield wiper fluid containers. Get a good long skinny funnel.

4.) Probe into the tranny with your skinny suck hose, while your helper pumps. Sometimes it takes a little to find the well of fluid. I'd only expect to get out about a quart or so, it's hard to get all of it.

5.) Once you are satisfied that you have gotten out all you'll get, put the container filled with used fluid on a level surface and put the empty one beside it.

6.) Fill the empty one with new fluid, to the same level (or actually, just a little more to compensate for the amount that will stick to the walls of the container). This ensures that your replace the same amount that you took out, and saves a good amount of guesswork.

7.) Carefully pour the container with the measured, new fluid into the tranny using the funnel.

8.) During the following season, be sure to check your fluid occasionally.

I used an old car fuel pump and fuel line. Worked great. I did change it within an hour of running. I put the same amount I drew out (aprox 2 qts). The next time I ran boat I added maybe a 1/5 qt.

I will admit I first tried a $5 siphon from Kmart... don't bother!

I will change every 100-120 hours.

I have used a tall pump from a tall bottle of hair shampoo/conditioner for the last five years. Do measure into an empty container what you pump out. It is sometimes tricky to get the hose down into the sump area of the tranny. Cheap and effective!
May do mine this weekend.