Chapter 17 Wheel Alignment Procedures 381 Copyright by Goodheart-Willcox Co., Inc. Note: It is not necessary to use new shims during every alignment. Used shims can be saved and reused. Shim opening sizes vary according to the size of the attaching bolts. Be sure to use the right shim. A shim with a small opening will not fi t over the attaching bolt prop- erly a shim that is too loose will vibrate out under normal operation. If the shims are diffi cult to reach or keep in place, hold them in place with grease or air conditioner insulation. Be sure to place the shims completely down over the bolt. Improperly installed shims can work their way out as the vehicle operates. Aft er the right number of shims have been installed, tighten the bolts securely and recheck camber and caster. Another upper control arm alignment method uses slot- ted holes in the vehicle’s frame or control arm, Figure 17-46. To adjust this type of control arm, slightly loosen the attach- ing bolts. Th en, move the control arm using a special tool, Figure 17-47, or a large pry bar. Oft en, moving only one side of the control arm will accomplish the alignment. If the control arm will not move, loosen the bolt on the side to be moved and try again. Caution: Do not loosen the bolts any more than necessary to move the control arm. The arm will slip and the alignment will have to be started over. If one side cannot be moved without backing off the bolt, be sure to retighten the bolt before trying to move the other side. Once the control arm is positioned correctly, tighten the mounting bolts securely. Th en, recheck camber and caster. Some vehicles have eccentrics at the control arm bush- ings for adjustments. Th ese eccentrics are generally located on the upper control arm, Figure 17-48. On a few vehicles, the eccentrics are located on the lower control arm. To make the adjustment, loosen the control arm bolt and turn the eccentric as necessary. Th en, retighten the bolt and recheck caster and camber. Note: As you gain experience, you will learn how to move adjusters to get the desired caster and camber with a minimum of time and effort. Until you develop that experience, you may need to make adjustments several times to get a perfect alignment. Bolt Slotted holes Frame Upper control arm FMC Figure 17-46. Upper control arm alignment on this vehicle is provided by slotted holes in the frame. The two bolts are loosened, allowing the control arm to be correctly aligned. The bolts are then torqued to specifications. Inner shaft Upper control arm Frame Special alignment tools Perfect Circle Figure 17-47. Special control-arm alignment tools being placed into position. This control arm also uses slotted holes in the frame for alignment. The two tools will move the control arm and the inner shaft easily. Frame Control arm mounting bracket Steering knuckle Upper control arm FMC Figure 17-48. This upper control arm is properly aligned using dual eccentric cams.