Getting ready to jump on the Lolo Motorway in Montana and wanted to see if I needed to be concerned. I shifted into Low yesterday and now back in High but I can hear some rattling going on at highway speeds when on the gas. If I hold the shifter the noise disappears. I have tried numerous times back and forth to get it to stop but it hasn’t. Any guesses? Everything seems fine otherwise. I don’t need a problem out there.