Yes, I believe it is the AX5. It has an 8 digit serial number code on the bottom, which I believe is true for the AX5 and AX4. It also has the intermediate plate in the center of the transmission (perpendicular to shaft). It does not split in middle, parallel to shaft.
I will have to check the fluid level, that would be a relief if that is the problem. How long have you gone on yours with that noise?
Pete - I thought it was the throwout bearing as well, but I just put a new clutch kit into it, including the t/o bearing, and it still makes the noise.