1942 - 1947 Chevrolet Shop Manual



	10-5

	To correct this condition we must add weight to sections 1 and 4, so they will be equal to the weight of sections 2 and 3. Notice that this addition of weight now distributes the total weight evenly about both the axis of rotation and the center line of the wheel as seen in Fig. 10-B. There-


	Fig. 10-Wheel In Static and Dynamic Balance fore, this wheel is now both statically and dynamically balanced. Wheels must be both statically and dynamically balanced to give maximum steering ease and stability at speeds where unbalance becomes noticeable. The wheels must be statically balanced before they can be balanced dynamically. To demonstrate the balancing of a wheel assembly we will use a combination static and dynamic wheel balancer, as shown in Fig. 11. Before the wheel assembly is balanced, the wheel and tire must be clean and free from all foreign matter. The tires should be in good condition and properly mounted, with the balance mark on the tire lined up with the valve stem in the tube. Bent wheels that have a run-out of over 3/16" should either be replaced or straightened before being balanced. CHECKING FOR STATIC BALANCE The static balancer operates on the principle of the pendulum and lever arm. The pendulum is mounted free to pivot, as shown in Fig. 11. An extension of the pendulum rod with suitable cones forms an arbor for the wheel which is to be balanced. Any unbalanced weight on the wheel assembly when mounted on the arbor acts through	Fig. 11 -Dynamic Wheel Balancer
		the wheel as a lever arm and tends to move the pendulum off center. The amount of movement depends upon the amount of unbalanced weight, and is indicated on the scale below by the pendulum pointer. Before placing a wheel on a static balancer, be sure that the pendulum pointer falls directly over the center mark on the scale. If it does not, the scale may be moved slightly to either side to compensate. To static balance a front wheel, place the wheel on the static arbor with the brake drum up. Using the regular wheel bearings between the special balancing cones, tighten the arbor nut (with fingers) sufficient to remove play and so that the wheel rotates easily. When placed in a horizontal position, as in this test, every wheel and tire assembly will have a place where it balances statically. Obviously, this place will be through the center of the heavy section of the wheel. Therefore, with the wheel in position on the arbor, turn the wheel slowly until in balanced position (balanced position is determined when the pointer on the pendulum rests directly over the center line of the scale). Now place the adjusting rod (furnished with the machine) on the arbor so that the mark "1" is directly in line with the mark stamped on the end of the arbor. Now raise or lower the counterweight by turning right or left until the pointer on