John Deere Heavy-Duty Flail Mower 390

Place draft control lever fully forward to the position marked "OFF" (A) for no draft sensing

Extend tractor telescoping draft link ends (if equipped)

Back up the tractor to mower with hitch points approximately in alignment

Engage tractor park brake and/or place transmission in "Park"

Shut off engine and remove ignition key

Remove center link mounting hardware and hitch pin assemblies at both hitch masts

Align draft links with hitch masts and install hitch pin assemblies according to the tractor hitch category. (See POSITIONING HITCH PINS in Preparing the Mower section)

Carefully back up tractor making sure both left and right draft link ends lock

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 driven shaft bearing mounting bolts (A)

Remove bolts (B) from driven shaft shield support

Remove PTO driveline shield (C) by removing (4) bolts (D)

Loosen (4) Support bolts for gear case (E)

To release bolt heads, slide the gear case forward in the grooves

Pull up the gear case towards the opposite side of the driveshaft

Apply multipurpose grease on output shaft of gear case

Tighten bolts to specifications

Install PTO driveline shield (C) on the correct hole locations (F) as illustrated

Apply multipurpose grease on the input shaft of gear case

Align splines by rotating mower driveline

Pull locking collar (A) and simultaneously push driveline onto the input shaft of gear case until locking device engages

Pull back on shield (B) to make sure that driveline is locked

Attach PTO driveline shield chain (C) to a fixed point on mower

Install rubber if equipped safety (A) deflector to the inside of the mower mainframe using provided hardware

Tighten all mounting hardware after deflector installation

Sign off on the PTO Driveline and Rear Safety Deflector Replacement

Warning: Ensure the mower is turned off and unplugged before starting the inspection

Measure the knife hole for the securing ring

Knife hole for the securing ring is not worn by more than 3.2 mm

Sign off on the knives inspection