Rear wheels have no traction
So my young son has been obsessed with removing tyres from his vehicles and Lightning was no exception. After 2 years of losing the tyre it was found again but now lightning has no rear traction on smooth or carpeted services. I've cleaned out dirt, used wd40 to lubricate but to no avail.
What am I missing? I've never worked on a RC car before so conplete rookie.
Thanks for your help.