Checking and Adjusting Mower Deck Level

Rotating blades are dangerous. Before adjusting or servicing mower:

  • Disconnect spark plug wire(s) or battery negative (-) cable to prevent engine from starting accidentally.
  • Always wear gloves when handling mower blades or working near blades.

Mower deck wheels should not contact the ground when leveling the mower deck.


Method One

  1. Make sure that machine is on a flat, level surface.

  2. Park machine safely. (See Parking Safely in the SAFETY section.)

  3. Check that tires are inflated to correct tire pressure. Tire pressure marked on tire sidewall is usually maximum allowed pressure. (See Tires in the SPECIFICATIONS section.)

  4. Raise deck to highest position.

  5. PY43331
    PY43331-UN-30MAY17

    122 cm (48 in.) Mower Deck Shown

    Place three short 51 mm (2 in.) blocks of wood under the edges (A) of the mower deck.



  6. Lower mower deck to the 63 mm (2.5 in.) cutting height position.

  7. Check that the mower deck is level and lightly touching each of the three wooden blocks.

    • APY08067
      APY08067-UN-30MAY18

      Mower Deck Lift Link

      APY08068
      APY08068-UN-30MAY18

      If the rear of the mower deck is not touching the rear blocks, or is sitting heavily on the blocks, adjust the rear lift links by turning the leveling nut (B) on each lift link. The blocks should be able to easily slide in and out beneath the mower deck when the mower deck is correctly adjusted.

    • If the front of the mower deck is not lightly touching the front block, adjust the front draft arm by turning the nut (C).



  8. Raise the cutting height to the next highest position and remove the three wooden blocks.

  9. Turn the nut (C) on the front draft arm counterclockwise 1-2 full turns so that the front of the deck is 3-6 mm (1/8-1/4 in.) lower than the rear. This adjustment prevents “double cutting,” which wastes horsepower and causes brown grass tips.

    Mower Deck, Front-to-BackHeight3-6 mm (1/8-1/4 in.)


Method Two

An optional mower deck leveling gauge (AM130907) is available from your John Deere dealer. It allows for precision mower deck leveling by measuring mower deck level at the blade tips.

  1. Make sure that machine is on a flat, level surface.

  2. Park machine safely. (See Parking Safely in the SAFETY section.)

  3. Inflate tires to the correct pressure.

  4. Move mower lift handle to preferred cutting height.

  5. Measure mower deck level (side-to-side).

    GXAL41983
    GXAL41983-UN-04MAR13

    Leveling Gauge (A) (AM130907)

    1. Position mower blades as follows and measure from each outside blade tip (B) to the level surface.



    2. GXAL41984
      GXAL41984-UN-04MAR13

      Turn left blade (C) as shown. Hold drive belt and turn the right blade (D) as shown. Take measurement for both blades.

      The difference between blade measurements must not be more than specified distance.

      Mower Deck Blade Outside Tips to Ground (Difference) Distance3 mm (1/8 in.)



    3. APY08069
      APY08069-UN-30MAY18

      Adjust mower deck level, if necessary, by turning rear nuts (E) clockwise to raise the side of the mower deck, or counterclockwise to lower the side of the mower deck.



  6. Measure mower level (front-to-rear).

    GXAL41986
    GXAL41986-UN-04MAR13

    1. Turn right blade (F) so blade tip points straight forward.

    2. Measure from the blade tip to the surface. Take measurement for both blades.

      The front blade tip must be specified distance lower than rear blade tip.

      Mower Deck Blade Outside Tips to Ground (Difference) Distance3–6 mm (1/8 -1/4 in.)



    3. APY08070
      APY08070-UN-30MAY18

      107 cm (42 in.) Mower Deck Shown

      Adjust mower deck level, if necessary, by turning the nut (G) counterclockwise to lower the front of deck or clockwise to raise front of the deck.



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