1998 Buick Riviera Owner's Manual - Page 275

a The vehicle should not have snow, ice or mud any attached toit. may flash their high beams at you if your adjustment is much above plus degrees. 0.4 The vehicle should be fully assembled and all other If you find that the headlamp aiming needs adjustment, work stopped while headlamp aiming is being done. follow these steps: a There should not be any cargo or loadingthe of vehicle, exceptit should have a tank of gas and full one person or160 lbs. (75 kg) on the driver's seat. e Tires should be properly inflated. e Rock the vehicle to stabilize the suspension. Start with the vertical headlamp Don't try to adjust aim. the horizontal aimfirst. Adjustment screws can be turned with anE8 Torx@socket or T15 Torx screwdriver. NOTICE: To make sure your headlamps are aimed properly, read all the instructions before beginning. Failure to follow these instructions could cause damage to headlamp parts. For the vertical adjustment, state inspection stations generally will allow a reading plus 0.76 degrees or of minus 0.76 degrees from the center the bubble. of It is recommended that the upper limit not exceed plus 1. Check the vertical aimfor each headlamp. The vehicle must be on level surface. Turn the vertical a 0.4 degrees from the center of the bubble. Other drivers aiming screw until the bubble the level is centered in at 0 (zero). 6-34