Bizarre differential problem

[glypo]

Even since changing to the new outdrives (not the problem as far as I know) I have had a problem.

One of the differential loosens itself. It is becoming a major pain now. Simon Moss rebuilt it all at the Petit RC race except for the thrust bearing (thanks for the help) but the very next round it came loose. I then rebuilt the thrust assembly and it was fine for the rest of the meeting.

Today at Newbury however it would only last about 3 or 4 laps before slipping. I completely stripped, cleaned and rebuilt (AE Black grease on thrust bearing, AE White on diff components) the thing twice with no luck.

I have used ball diffs for 14 years, and often leave them when dirty and mucky without issue. (Simon said the black in mine was not good at Petit Race, glad he hasn't seen my Mi2EC...) Yet this is a mystery. No-one seems to be able to figure it out. The grub screw is proper locked in place, and it seems fine.

My personal feeling is, it's the stupid "disc springs". The thing is, no-one else has had a problem as far as I am aware. So, opening to the general public... has anyone got any suggestions please?

Thanks