We did have some problems with the transmissions we made last year. We did not follow the NBD white-paper and had some problems. We ended up going through about 8 transmissions in 2 competitions. We ended up stripping out a few of the metal housings because of the changes we made. Since last year we have reworked the transmissions and we don't seem to be having the same issues. If you read the white paper written by one of my students,
http://www.chiefdelphi.com/media/papers/2826 you will better understand the problems we faced. If you look at the pictures he included in the white paper you can get a rough idea of our design. (& by we & our I mean their & their's)
Our design worked well when not used for shifting because we could just clamp it down into place. The ones we have re-worked to Dr. Joe's specs seem to be working much better.
** this is not an attempt to pirate this thread but...
We tested out some Andy-Marks this fall and they worked great. There is a HUGE difference in cost between the 2 ... if done correctly the first time. But if you never screw up how will you know if something doesn't work.