John Deere Heavy-Duty Flail Mower 390

Keeping Mower Clean (Every 10 Hour or Daily)

Drive Pulley Bearing and Gauge Roller Bearings (Every 50 Hour)

Check hitch pin lock nut (A) on pivot plate periodically to be sure that it is tight.

Tighten to specifications. (See CAP SCREW TORQUE VALUES in Specifications Section)

Loosen (2) mounting bolts (A) in the idler adjusting arm

Turn the adjusting nut (B) counterclockwise until belt is released

Remove drive pulley by removing bolt (C)

Remove used belt and install new one

Align drive pulley. (See ALIGNING PULLEYS in this section)

Turn adjusting nut (B) clockwise to get the proper tension. (See ADJUSTING DRIVE BELT in this section)

Tighten mounting bolts (A) (See torque value charts in Service section)

Sign off on the belt replacement

Warning: Ensure the mower is turned off before starting the procedure

If the mower is not turned off, turn it off and then proceed

Is the top bolt (B) removed from each end of the roller mounting?

Is the lower bolt (C) in each end loosened?

Enter the desired cutting height (in mm)

Is the roller positioned for desired cutting height according to chart?

Sign off on the cutting height maintenance

Loosen (2) mounting bolts (A) in the idler adjusting arm

Turn the adjusting nut (B) clockwise to increase tension and counterclockwise to decrease tension to specification.

Tighten mounting bolts (A) (See torque value charts in Service section).

Check if the bolts are properly tightened

Sign off on the drive belt maintenance