I've noticed a loud clatter or clanking at idle coming from my StepWGN when I'm paying for fuel, almost like something loose reaching a resonant frequency. I am quite concerned about it. The sound bounces of the nearby wall of the kiosk and through the window as I'm travelling at a few MPH. I'm worried the sound might be gearbox, but I don't know why really. I took the auxiliary belt off a few weeks ago, and the tensioner, power steering pump, and alternator bearings were solid, so I suppose that would leave the water pump and air con compressor to check? I suppose it could also be something like an exhaust heat shield, but it really is loud. It could be there when I'm driving at speed, too, but it is just going unheard...I need a wall and the windows down to hear it. Has anyone got any suggestions for lines of inquiry? The oil in the gearbox is a nice clear red, so I didn't think it needed changing, but the car has just gone over 60k miles, so I perhaps should change it as a matter of course, and I have a new filter to fit. What is the correct oil to get and should I go to Honda for it? - - - Updated - - - I should add (can't edit yet), I have the 4-speed conventional auto gearbox.