Ouch.. Thats all I can say.
THat "klunk" you heard was probably your engine mounts going to there limit... At 4000RPM and just dumping your clutch, I feel there pain from here in Nova Scotia. ANd any and all other drive line catching up.
If you have not heard it since, then I would not be to worried about it. Just learn how to do it correctly before you attempt it again.. Trust me, 2G AWD trannys are not easy to find.