Alamo GR72 Brush Cutter User Manual


 
MAINTENANCE
GR60/72 02/07 Maintenance Section 5-7
© 2007 Alamo Group Inc.
MAINTENANCE
Slip Clutch - GR60
A slip clutch is incorporated in the PTO driveline. It is designed to slip, absorb the shock load, and protect the
driveline. There are two types of clutches furnished. (1) A clutch with 8 coil springs and (2) A clutch with a
single disc spring with 6 adjusting nuts.
After the first hour of operation, the slip clutch should be checked for overheating. After this first check, the
slip clutch should be checked weekly or anytime there is overheating. (1)To adjust the coil spring slip clutch,
tighten the spring bolts 1/8 (maximum) turn at a time. Bolts should NEVER be adjusted to the point where the
coil springs are compressed solid. Minimum spring compression length is 1-15/32". (2) To adjust the disc
clutch, tighten the 6 bolts until they bottom out and then loosen each of them 2 turns.
The slip clutch should be checked periodically and adjusted to compensate for wear. The lining plates are 1/8"
thick when new. Replace after 1/32" wear. If the mower has been idle for an extended period of time, or in wet
weather, before operating check to be sure the friction lining plates are not rusted/corroded together. Should
this occur refer to the procedure described in the "Seasonal Clutch Maintenance" section on the next page.
Seasonal Slip Clutch Maintenance
It is important that the clutches slip when an
obstacle or load heavier than the clutch setting is
encountered. Therefore, if the machine sits outside
longer than 30 days and is exposed to rain and/or
humid air it is important to make sure that the clutch
lining plates are not rusted/corroded together.
Before using the cutter use the following procedure
to make sure the clutch will slip and give the
overload protection required.
1. Loosen nuts (Mnt-0017) on springs until the
springs are free, yet remain secure on bolts.
2. Attach cutter to tractor and start the tractor.
Set the engine speed at 1200 RPM.
3. Mark outer plates as shown in Mnt-0017.
4. Engage the PTO (approximately one
second) and then quickly disengage it. The
friction lining plates should break loose
(check the mark).
5. Turn tractor off. (1) Tighten the nuts on the
coil spring clutch to their original position of
1-9/16" compressed spring length. (2) (Top
of washer to pressure plate)