Uhh...I hope this isn't a dumb question? Anyway, I recently swapped the stock radio with the TQ-4 2.4Ghz radio. It seems to be working fine, but I used to remember(I don't use the Summit that often) when I locked the front,rear, or both...I would hear a click and see the vehicle engage the drive. Now, I just hear the servos move, but it doesn't seem like anything happens. Right now, in the fully open positon all four wheels are turning with throttle, if I lock the front, rear, or both...I do not see any difference...all four wheels are still spinning. Does this sound normal? The servos are moving, but I have feeling it's not engaging? Any advice or comments are appreciated. Thanks!