The other day I had my airbox off and thought ...what a perfect time to check the tranny. I twisted the cap fully counter clockwise and it just hit a stop. Tugging did not help. It did not want to come off. I tried turning back all the way clockwise. Same thing. I did not want to force things till I was sure. I looked in the owners guide and got no clue there about the stubborn dip stick cap. I left it fully at the stop while turning clockwise. Any suggestions?