The downside of the symmetrical elevators, is that when pick up with areas of chassis unique for this task (vehicles with only 4 points of attachment) or vehicles with a different structure than the average in terms of weight distribution, becomes a more complicated task. The problem of this is that we have a front arms that measure like the rear, therefore, if the car in question has a short measure between front wheel and rear, we will be forced to place the vehicle in the elevator, bouncing close first front deadlines, move the vehicle and close the rear. This is because arms collide on the wheels before you can turn from open to its final attachment point. (It usually occurs with very few vehicles and out of the ordinary. Especially sports and low. Asymmetric these elevators are distinguished because the front arms are shorter and assets of greater thickness of manufacturing (especially in elevators with structures weakest since lower front arms distance force that the heavier part of the vehicle (usually front with this engine) be loaded in such a way that the greater weight of this to the lesser distance column, leaving the pair delayed back that the subsequent arms in its extended position supporting a prisoner balanced at all times. 5B. do electric worm or lifting hydraulic lifters? Electric lifts or screw: electric elevators or also called worm has been marketed and distributed by all car repair centers for decades throughout Europe. European producers thought it was the right idea to manufacture their elevators. Electric elevators or screw elevator, are composed of a fixed structure, divided into two functions the first meets guide that at all times the movements may be correct, and second officer in exercising the movement of ascent or descent via an electric motor of great power and consumption that drives in shape turning a screw without end normally installed in a single column, and being at the same time and by means of a distribution consisting of two sprockets on its bottom and a string, manages to repeat the movement synchronized in the second column.