Yesterday when I was cleaning my 1:8 buggy I saw that when I spin one wheel opposite wheel spin in same direction (not in reverse way as it should). Car is running well and there is no sound out of diff. What is wrong?

Have you checked the diffs by taking them out an having a close look? have you put diff back in wrong way, do you maintain it on a regular basis as in diff oil changes

does your buggy have lsd? if so thats what they are supposed to do

That just means the center is diffing out before the oposite wheel is,

It's not that unusual, but it could be a sign that the diff needs service, the oil or grease might be getting "gummy" inside.

Hold the center drive cup still and then spin the wheel,,, what does it feal like?
if the wheels don't want to turn easily you might have a problem

I never put diff out from car, car is 2 month old, 1 gallon of fuel spent. How often should I change diff oil.

It's normal.

Why is this thread showing that there is a new post by LSTCrazy.... but I can't read it?
It's not the first time this happens. [sm=confused.gif]

you must have him on your "block" list,, I can read it

I can read it now too but it takes a day or so before his posts show up. Same thing happening in the OS RG-X vs Sportwerks thread now.
[sm=confused.gif]

he must be on probation