Great Plains YP925TD Operator Manual - Manual (Page 89)

Great Plains Manufacturing, Inc. Table of Contents Index Maintenance and Lubrication 85
02/23/2011 Table of Contents Index 401-755M
Marker Maintenance (Option)
See also:
“Initial Marker Setup (Option)” on page 120,
“Marker Operation (Option)” on page 33, and
“Marker Disk Adjustment” on page 48
Marker Shear Bolt Replacement
Refer to Figure 90
If a marker gets caught or hits an obstruction, it is
designed to fail a shear bolt
at the fold, pivot on a
second bolt (not visible in Figure), and swing back.
The shear bolt is a hex head cap screw, 5 ⁄
16
-18 x 1 1 ⁄
2
in
Grade 5, Great Plains part number 802-012C, plus a
5 ⁄
16
-18 lock nut, Great Plains part number 803-011C.
Note: If an exact replacement is not immediately
available, temporarily substitute an M8x1.25 Class
8.8 bolt and nut.
Install a replacement shear bolt on the vertical face on
the side opposite from the pivot bolt. Do not use a higher
grade bolt, or marker hang-ups may result in machine
damage. Do not use a lower grade bolt, or you may
experience nuisance shears.
Marker Grease Seal Cap
If grease seal cap for marker-disk-hub bearings is
damaged or missing, disassemble and clean hub.
Repack with grease and install new seal or grease cap.
Figure 90
Marker Shear Bolt
31794
3
3