Ok, 2011 RGU, just under 38k miles. Stock other than mufflers and plugs/wires. Went out for a ride today and when I got on it hard heard a rattling noise in 2nd and 3rd when the RPM's got up around 4k. Couldn't replicate it when not rolling, when in neutral or when at a stop with the clutch in it wasn't there. Didn't try taking it that high in 4th and didn't really notice in 1st. Any ideas?