Mower decks are located underneath the mower, and are typically 12 to 18 inches wider than the body of the mower. The blades for cutting grass are housed beneath the mower deck. Uneven mowing can be caused by damaged or loose blades; clogged mower deck vent holes due to build up of grass, leaves and other debris; or more commonly an uneven mower deck. Mower decks can become uneven over time and need to be checked prior to each use of your Craftsmen mower.
Park the mower on a level surface, such as a driveway. Disengage the mower blades and engage the parking break. Turn the mower off and remove the key.
Lift the mower deck to its highest position using the lever to the right of the seat. Move behind the mower so that you are viewing the mower deck from the rear. Measure the distance from the bottom of the mower deck to the ground on both sides. There should be no more than ¼ inch difference between either side.
Adjust only one side of the mower by turning the link adjustment nut located on the bottom of the suspension arm. Raise the mower deck by turning the nut clockwise to tighten it. Lower the mower deck by turning the nut counter clockwise to loosen it. One full turn of the nut will adjust the mower deck by 1/8 of an inch. This adjusts the mower deck from side to side.
Move to the mower's right hand side, based on viewing the mower from the rear, to make a front to back adjustment. Measure the distance from the bottom of the mower deck to the ground at the front and back corners. The rear of the deck should be ¼ inch to ¾ inch higher than the front of the mower deck.
Measure the distance between the front links. This should be 10 3/8 inches. If it is not, adjust one link so that it measures the same distance from the pulley located in the center of the mower deck, called the mandrel, as the other.
Lower the front of the mower deck if needed by turning the nut on the front of the trunnion on both front links. The trunnion is the connecting piece that holds the front links in place. Turn each side an equal number of times in a counter-clockwise direction. Tighten the nuts on the back of the trunnion by turning clockwise once the front of the mower deck is ¼ inch to ¾ inch lower than the rear.
Raise the front of the mower deck if needed by loosening the nut on the rear of the trunnion on both front links. Turn the nut on the front of the trunnion on both front links an even number of times. Once the mower deck is in position, turn the nuts on the back of the trunnion clockwise to tighten.
Check the side-to-side alignment to make sure that it has not moved while adjusting the front to back alignment of the mower deck. Readjust if necessary.