Transmission 5hp-19. The gearbox pan was hit and the oil level in it dropped. The box went into emergency mode. After reading the error "4th gear clutch slip" and resetting the error, the gearbox went out of emergency mode. Now sometimes the gearbox disappears on the move, the revs are increasing, but the car is not picking up speed in any of the gears. But the speedometer is increasing, as if the car is moving.