Gravely Promaster 160 Owner's/Operator's Manual page 23

Blade Side-to-Side Level
Left
Blade Front-to-Back Pitch
Rear
Adjust Blade Height
Level and pitch the mower with the height adjusters on each
deck lift bracket (Figure 23).
Loosen the jam nut on the deck lift bracket bolt about
1/4 turn to reduce clamp load on the height adjusters.
Loosen the jam nut on the deck adjuster bolt and then
turn the bolt clockwise to raise the deck or
counterclockwise to lower the deck. Tighten both jam
nuts.
Right
Front
Rear
Figure 22
Height Adjusters
GB - 23
DO NOT place
blocks under
reinforcement bar.
Figure 23