WOW! 18th scale owners found out how to put a shim on a diff! Wow...
heres a link to the "mod" -
http://www.beatyourtruck.com/forum/s...ht=optimus+mod
What might qualify this as a mod is that the shims are "spring washers" -
http://www.mcmaster.com/#9712K58
the mlst2 has metal diff spur/pinion gears iirc so shimming the diffs should stop the problems.