I will do a write up of how to prevent the internal gears from stripping. I had the same problem and cured it easily. The viscous diffs are the best available for the mlst. All of the others I tried were junk. I have a bunch of mlst diff parts, pm if interested, I will let them go cheap as I have no use for them now. Give me a few hours and I will post up a tutorial on the viscous diffs.