Before I came to Iraq I noticed that when I would drive my P5 It would grind going from 1st to 2nd and 3rd to 4th but only when Im switching gears fast at high RPM's. When Im driving normal it doesnt grind. Is It time to get a new tranny? My P5 has 89K and the tranny fluid has been changed recently. Would It be cheaper to buy a used tranny or just rebuild it? Thanks.