Originally Posted by Gizmatron

Thanks for the sympathy... anyway I think I sorted the problem ..I replaced the old diff housing with a new one ..well an unused one anyway and I just found out Kyosho replaced the part number with a new one made from the same newer material as the replacement ones for the mp9 IF121C instead of IF121..I bet the older weaker more flexible plastic is giving enough with the MG66 power to cause the diff gear engagement to open and wear the teeth prematurely..The bearings on the centre driveshaft pinion certainly aren't a tight fit into the plastic anyway - practically drop in..2xthe newer ones on their way with yet another 13T pinion gear..Lucky they are cheap...
shame I still beat everyone at the last demo with the MG66 even though I only had front wheel drive on my 4x4...Muahahahaaha!!!