Service Bulletin

SEAL INSTALLATION INSTRUCTIONS
For Greensmaster
®
Flex 21 and DPA Cutting Unit Rollers
Roller and seal performance can be checked with a spring scale or a torque wrench
with the ability to read 6 in-lb (0.68 Nm) near mid-scale on the dial. If the rolling
resistance exceeds this value, the roller will need to be corrected.
Seal installation procedures.
1) Use grease on the ID of the seal and shaft to ease installation. Grease on the OD of
the seal is not required.
2) Before pressing the seal into position, smear some grease around the inside next to
the bearing to help counter corrosion effects. Do not pack the area with grease or the
seal will be difficult or impossible to install due to a hydraulic lock effect.
3) Correct any damage in the bore (especially the leading edge) before installing seal.
4) Try to push the seal into position or use a press to place a steady force onto the seal
to avoid deforming the case of the seal. If at all possible, avoid the use of a hammer
or and other object to strike the seal.
5) Use a seal installer designed for the job or a piece of tubing that can contact as much
of the full surface of the seal as possible (from ID to OD). The seal installer can be
metal or plastic.
6) Push the seal into position until it is flush to the outside bore. Do not go much
beyond flush to avoid making contact with the 45-degree chamfer on the shaft.
7) Once the seals are in position, lightly tap the shaft back and forth to assist the seal
section attached to the shaft in seeking a relaxed position. Turn the roller at least 10
revolutions and test the rolling resistance to be 6 lbs (0.68 mm) or less. This is done
with a string wrapped around the roller and a spring scale. Hold the shaft in a vice.
NOTE: An alternative method is to use a 12 point metric socket (15mm) wedged over
the end of the shaft. Once in place you can use a light-duty inch pound torque
wrench to turn the shaft. Tools such as torque wrenches are most accurate
when the desired value is near the midpoint of the scale, so be sure to use a
torque wrench small enough to register accordingly.
8) If the roller is above spec, repeat the tapping and rolling of the shaft back and forth in
an effort to relax the seal. The goal is to gain a relaxed state inside the seal (see
cutaway picture attached).
Internal seals