Porsche 1973 Wheel Alignment Repair Guide

1973 PORSCHE SPECIFICATIONS AND ADJUSTMENTS

TIRE INFLATION (COLD)
Before attempting to check or adjust wheel alignment, make sure tires are properly inflated. Refer to manufacturer's specifications given in owner's manual.
RIDING HEIGHT
NOTE - Riding height should be set with full tanks of gasoline and spare tire included.
All Models (Front) - Checking or adjusting riding height can only be performed with vehicle on level surface. Mark center of front wheel hub cap (grease retainer cup). Bounce vehicle several times to settle suspension. Measure distance "a" as shown in illustrations, then measure distance "b". Difference "a" and "b" should be to specifications. If necessary to adjust, loosen or tighten torsion bar adjusting bolt until correct height is obtained. Bounce vehicle several times and recheck height. NOTE - Difference between right and left measurement must not exceed .20".

911 Series (Rear) - Checking or adjusting riding height can only be performed with vehicle on level surface. Mark center of rear wheel. Bounce vehicle on level surface. Mark center of rear wheel. Measure distance "a" as shown in illustrations. Distance "a" plus .468" euals "b"; however, distance "b" is difficult to measure because the torsion bar is mounted off center in its rubber bushing. Therefore, it is necessary to measure distance "b 1" and add .585" (radius of bushing). This total should be equal to "b" should be .468±.20". Difference in height from left to right should not exceed .197". If values are not within specifications, check front height and rear torsion bar adjustment. Correct as required.
CASTER
All Models - If caster angle is not to specifications, it will be necessary to move adjuster plate which attaches to front shock absorber. Remove enough front compartment carpet to allow access to top of each shock absorber. Mark position of each movable plate, located below each Allen screw. Loosen each screw and upper shock absorber nut. Move assembly lengthwise to obtain correct caster angle. Tighten all three screws and shock absorber nut. NOTE - Movement of adjuster plate from side to side will affect camber angle.
CAMBER
All Models (Front) - If camber angle is not to specifications, it will be necessary to move adjuster plate which attaches to fornt shock absorber. Remove enough front compartment carpet to allow access to top of each shock absorber. Mark position of each movable plate, located below each Allen screw. Loosen each screw and upper shock absorber nut. Move assembly from side to side to obtain correct camber angle. Tighten all three screws and shock absorber nut. NOTE - Movement of adjuster plates in lengthwise direction will affect caster angle.
911 Series (Rear) - Mandatory prerequisite, for obtaining permissible camber values at rear wheels, is proper adjustment of rear torsion bars. See Torsion Bar Adjustment. Loosen nuts on retaining bolts and nuts on eccentric bolt at rear axle flange. Turn camber eccentric until camber angle is within specifications. Tighten retaining nuts and eccentric bolt nuts.
914 Series (Rear) - Mark position of rear axle control arm on base plate and remove center bolt. Loosen remaining bolts. Change shims between control arm bushing and body. Shims are available in .039" thicknesses. Addition or removal of one shim changes camber angle by 10'. With camber angle to specifications tighten all bolts.
TOE-IN
All Models - Place wheel in straight-ahead position. Adjust left and right steering links (tie rods) equally to obtain specified setting. Coat each steering link with anti-corrosive compound after adjustment.
TORSION BAR ADJUSTMENT
911 Series (Rear) - Place torsion bar into transverse tube with inner end splines first. Slip radius arm onto outer end splines of torsion bar. Place suitable leveling tool (VW 261) on lower edge of door opening and adjust level so bubble is in center of glass. Check adjustment (degrees) of free hanging radius arm with some leveling tool. If not to specifications, adjust by turning torsion bar and radius arm in opposite directions. Adjustment of both radius arms must each equal 36°45'±15.