Thank you for your response, i already replaced the two traction motors and still jerking , also i replaced the power cables from the battery to the main controlers to make sure that the current is not intruptted at any point but all invain and i'm still getting the same problem.
there is one more thing i'm going to check which is the brake oil sensor which may be faulty and giving a false signal to the traction motors. i will update you incase it solved the problem or no.