I think I've reached intermediate status now in terms of R3 tranmission removal and i can get it all apart in 1 day by myself. If i was i your shoes (Given what I've seen in terms of wear on a box with only 50k kms on it) I'd go all out and look inside...all the input here suggests that it's not really one thing in particular that causes the 'clunkiness' most of us experience.