Imageshack - file23969.mp4 - Uploaded by shaunpainephoto

There's the video, it literally makes no sense to me. I know that the trans is rooted, but this is the noise is makes when it's in 2nd engine braking, with a bit of throttle. It doesn't make this "whipple" noise in 1st, 3rd, or in D, either in that specific gear or not.

It's confused the absolute shizen out of me, any help would be appreciated.