RE: Tornado S30 What happened???
its not a good idea to drive any 4wd RC in just rwd. this is because all of the power is now just going to one diff(in this case the rear) and may have damaged it.
however, its very possible that if you replace the front and rear dogbones it will be fine.
see, the diffs will send the power from the motor to the wheel that can turn the easiest. in this case, both the front and the rear diffs are sending power to the wheel that has no dogbone.
you may want to upgrade to the steel CVDs. they are stronger than the dogbones and dont ever bind on the drive cubs like the dogbones can(this is often what will cause them to snap.
it would be a good idea to take your rear diff apart and check the gears. if it all looks good, add some diff lube or grease when you put it back to together.