911 & 912 Rear (1965-72)
Check rear axle height with vehicle on level ground. Bounce vehicle several times to set suspension at proper attitude. Mark center of rear wheel and measure dimension "a" as shown in illustration. To calculate "b1", add 0.472 in. to dimension "a" less radius of the bushing cover on torsion bar. Measure "b1". Calculated value should not differ from actual measurement by more than 0.197 in. The height difference between left and right side should not be more than 0.315 in. If values are not within limits, check height adjustment of front suspension and rear torsion bar adjustment. Correct if necessary.