Hi guys. Greetings from Malta.
Yorkie. We have had very little trouble with TC3 alloy drive shafts. We run mod - see results of Christmas Cup meeting in yesterday's posts, on a grippy tarmac surface, so there is plenty of load on the transmission. I replaced my son's TC3 drive shafts at the start of the season, just to start off with a new set, just as I like to start off the season with many new bits as a precautionary measure. Incidentally we also use the "factory team" plastic diff halves. They are the lightest/strongest combination presently available.
I have sold plenty of TC3s, and indeed quite a few of them run in modithout any drive shaft problems. I sell many more MR4 drive shafts than TC3.
A happy Christmas to everyone.
Regards
Joe from sunny Malta.