MCi Crusader II 1989 Maintenance Manual page 504

Date
1-1-89
Page __
,_s_-3_4 _ _
MC-9 MAINTENANCE MANUAL
3. Using a depth micrometer; measure and record the-
distance from the back of the armature to the face of the
rotor. See figure 16-48.
Figure 16-48: Armature-to-Rotor {Air Gap)
Measurement
4. Disconnect the clutch coil electrical lead. Ground one
connector terminal and connect 24 VDC to the other termi-
nal to energize the coil.
5. Repeat step 3 for the measured distance when the
armature and rotor faces are engaged.
6. De-energize the coil and determine the difference
between the two measurements. If the difference exceeds
. 110" (2.794 mm}, the clutch rotor and armature require
replacement. Proceed to step 7. If the distance is .110"
(2.794 mm} or less, clutch
wear
indicates replacement is
not necessary.
7. To remove the shaft-mounted clutch, ffrst open the
two-way manual valve to vent air pressure .from the drive
belt tension air cylinder.
8. Remove the two compressor drive belts from the
clutch rotor (pulley}.
9. Disconnect the coil electrical lead.
10. Ensure that clutch rotor.does noirotate, then remove
the capscrew, lock washer, and two flat washers mounting
clutch to compressor shaft.
CAUTION: Any bolts Installed in the arma-
ture puller holes must have stop nuts in
place to prevent insertion into the arma-
ture more than 1/1" {9.5
mm).
This will pre-
vent damage to the bearing seal.
11. Remove the rotor and armature assembly, along with
the locking key, from the compressor shaft.
12. Inspect the coil for damaged electrical leads, bent or
cracked mounting plate, or cracked coil potting com-
pound. Electrical resistance between connector terminals
of the coil shOuld be 5. iS-5.69 ohms. Resistance from either
terminal to the coil case (ground} should be infinite or
open. Replace the coil if defective.
CAUTION: Before lnstalllng new clutch
components, thoroughly clean compres-
sor half flange and shaft seal cover plate
of all dirt and grease. Use a clean cloth
and suitable cleaning solvent
Dry
clean-
ed surfaces thoroughly with compressed
air.
Proceed as follows to install clutch:
13. To install the coil, place it over the shaft seal plate and
align the mounting holes. Coil leads should be at the 4
o'~lock position.
CAUTION:
If
the coll will not seat, do not
draw It down flush by tightening the
mounting capscrews. This wlll distort the
coil mounting and cause misalignment
between coil and clutch rotor.
14. When coil is capable of flush mounting, install belt
tension cylinder mounting bracket and coil with the four
capscrews. Tighten the capscrews to 25-30 lb.-ft. (34-40)
Nm) torque.
15. Install the rotor and armature assembly on the com-
pressor shaft. Align the keyways and install the locking key,
large and small flat washers, lock washer and capscrew.
Hand tighten capscrew.
16. Insert a .020" (.508 mm} feeler gauge between the
O.D. of the coil and the coil cavity of the rotor. See figure
16-49. Holding the feeler in position. turn the rotor one
revolution to check for proper coil-rotor clearance. If rotor
turns freely, without binding, continue installation .
.
..
,
-
f
Figure
16-49:
Checking Coil - Rotor Clearance
17. Taking appropriate measures to prevent the crank-
shaft from rotating, tighten the mounting capscrewto max-
imum 20 lb.-tt. (27 Nm) torque.
CAUTION: Any bolts installed in the arma•
ture puller holes must have stop nuts in
place to prevent Insertion into the arma-
ture more than 1/," (9.5 mm). This will pre-