In the early records with torque of 80% and 100%, the gear mesh signal shows as a dark band at
indices 3 and 4 at the gear mesh frequency. Variation in the level with rotation can be seen. Record
44 shows greater variation with the amplitude reduced near 0.8 rotation. Examination of the
corresponding time history in figure A4 also displays lower signal amplitude near 0.9 rotation of the
pinion. In the 125% torque region (records 127-209), the amplitude for the gear mesh harmonic
becomes more variable and the gear mesh frequency component no longer always contains the
largest amplitude; at some positions in the rotation, a lower frequency has the largest amplitude. By
record number 240, the largest amplitude always occurs at a lower frequency. The rotation position
with the largest amplitude moves around through the remainder of the test. The amplitude of single
components increase around record 240 with a maximum level at record 443.