If you wanna try somthing other than the schui thrust I might suggest this Losi thust bearing.
http://www.rcslot.com/pc-radio-contr.../LOSA3098.html
I have one in both of the diffs in my foam carpet car and they have held up for the last three months. Diff still feels brand new. My LHS doesn't carry Schui parts and I was in a crunch for a new thrust a while ago. An xray owner suggested it to me. I do have to say there aint many if any thrusts better than the carbide schumacher thrust U1954. SMooooooo0th!
Dont use the washers that some with the Losi thrust though. Just use the original Schumacher washers.
Odd you say the Xray thrust doesn't work. Theres a driver at our track that I know is using the uuber expensive Xray thrust in his Mi3.
the xray, corally, and Mi3 thrusts are all the same size, or at least are interchangeable in my experience. The washers may not be however.