Hey guys I have never had this happen before. I have a Tremec TR3550 TKO, unfortunately I don't know the history of it, I "inherited" it. I tore it down and was in the process of rebuilding it.
I was putting it all back together and got down to putting the front bearing retainer back on. I was working on pulling the seal. I thought the seal finally came out only to realize the tube the throw out bearing rides on was in my hands and the back cover plate was falling to the floor!
The casting says its steel. When I got the transmission, the retainer had some surface rust on it which some 1000 grit sandpaper cleaned up pretty good.
When I unbolted it from the case, the input shaft that was concealed but the tube also had surface rust. Again 1000 grit sandpaper cleaned it up pretty good. Inside the tube again had more rust a little thicker, but after 10-15 minutes of running more sand paper through it it was cleaning up decently.
Has anyone ever had this happen? I've read posts where the shaft for the throw out bearing was broken or cracked when someone was pulling a transmission from the car, but I didn't see any cracks in this. So for it to break off in my hands surprised me. I'm not that strong!! LOL
Maybe it was ready to go and I just caught it early (thank goodness!)