XPRO - Crazy spinning Doughnut Machine

[Schawa]

Hi Guys,

New to this forum. I am from South Africa. Stumbled upon this forum in my search to get the best out of my son's TC02T (Same as XPRo truck). OK, OK, it is my son's although I spend most of the time with the car.

Bought lots of spares recently from TCModels after losing a diff. Ordered on Sunday evening, in my PO Box on Thursday!! Amazing service and speed, wow!!

Anyways, here is my question. The car's diff was rebuilt following all the instructions found on this great forum. Diff does not slip, feels reasonably smooth. Considerable effort to turn gear if both wheels are held. Slipper is a bit tight, but does slip when it should. When running on grass it seems like the car has a tendency to run towards the right, not as a result of front wheels turned that way, but as if the left back wheel has more power on it. No sharp turn, just a slide every now and then. I think it runs OK on grass even with the occasional tendency to the right - all in all very manageable to drive at speed.

When the car gets onto gravel/loose sand it is a completely different matter. Running in straight line once at speed no probs - BUT when pulling away from standstill causes and immediate doughnut, spins in circles. I think always clockwise. Only when you pull away slowly does it stay straight. Making turns at speed on gravel is near impossible without spinning out.

What's wrong - diff, steering, weight distribution/shocks (or just poor driving) ?

NB: It runs with 17T Brushed motor (also bought from TC a 3000KV brushless + 100A ESC but do not want to covert before fixing the spinning)