I have a question about checking the transmission fluid level on my 91 Hunter 37.5. I was told to unscrew and pull the dipstick plug, wipe it off and drop it back into the hole, remove and check that the level meets the indicated mark on the stick. I just want to make sure that I don't have to screw the cap back into the unit before I unscrew and check. The difference in readings is about 1/2 pint of fluid. I couldn't find this mentioned in my Yanmar Manual. Les s/v Mutual Fun