The mower deck on a Murray lawn tractor might require an adjustment for a couple of reasons. As the mower “breaks in,” the deck may begin to lean in one direction or the other. Also, accidentally bumping against a tree or wall with the deck while mowing might cause it to get slightly out of adjustment. If the mower deck appears unlevel, first check the tire pressures for equal inflation on both sides of the machine.
Level Deck Left to Right
Park the lawn mower on a level surface or driveway. Turn off the engine and set the parking brake. Visually verify the mower blades have stopped before beginning service on the mower deck.
Raise the deck to its highest level to perform a level adjustment. Measure the distance from the bottom edge of the deck to the ground on both the left and right sides of the mower. If there is a difference in the two sides greater than 1/8 inch, move to the lowest side to adjust it up.
Locate the lift links on the far left and right sides of the mower deck. The links attach the deck to the mower and provide support, as well as lift, for the deck. Each link has a single nut threaded onto a rod protruding through the link. Turn the lift link adjustment nut clockwise (if facing it from below) a complete turn using a crescent wrench. Each full turn of the adjustment nut raises the deck 1/8 inch. After adjustment of the lift-nut, measure both sides of the deck edge to the ground in order to verify proper adjustment.
Level Deck Front to Back
Ensure the deck is raised to its highest position. Measure the farthest front edge of the mower deck to the ground and record the height. Move to the rear of the mower deck and measure this distance from the deck’s edge to the ground. The difference between the two dimensions is ideally 1/8 to 1/2 inch lower in the front than in the rear. If the deck level is otherwise, relocate to the front of the mower to adjust the deck’s front links.
Loosen the front link jam nuts on the right and left side of the mower with the crescent wrench. The front links attach to the leading edge of the mower deck and run through the mower’s frame to support the front of the deck. After loosening the jam nuts, rotate the outside adjustment nut clockwise to raise the deck or counterclockwise to lower the deck. Make sure to turn both front link adjustment nuts an equal number of turns.
Re-measure the distance to the ground along the front and rear edges of the mower deck. Once the proper adjustment is reached, lock down the jam nuts with a crescent wrench.
About this Author
Damon Hildebrand is a retired U.S. Navy veteran. He has more than 15 years within the oil and gas industry in both technical and managerial positions. Hildebrand has been a technical writer and communicator for the last four years. He is a certified specialists in lubrication and tribology, as well as a certified maintenance and reliability professional.