Spicer Tandem Drive Axles Pro-40 Single Reduction and Single Reduction with Differential Lock - Manual (Page 54)

51 54
Forward Assembly
Install and Adjust Wheel Differential Lock
Note: With differential carrier completely assembled and
adjusted, install differential lock as follows:
1. Install fixed curvic clutch on splined hub of flanged
differential case, then install snap ring.
2. If shift fork and sliding curvic clutch are disassem-
bled, engage fork with clutch hub and install spring
pin in the long leg of the fork. See illustration for fork
mounting position on clutch.
3. Position compression spring, shift fork and clutch
assembly in shift opening of the carrier. Align pilot
hole of shift fork with pilot hole of carrier. Install
pushrod, engaging shift fork head, and compression
spring in carrier.
4. Install new o-ring on piston.
5. Lubricate piston and o-ring with silicone grease and
install piston assembly in cylinder. Position piston
with small diameter hub toward closed end of cylin-
der.
6. Screw piston driver on push rod.
7. Tighten piston driver until shift fork clutch is approx-
imately 0.030 of an inch from the fixed clutch.
8. Push down by hand on the piston driver, both
clutches must be completely engaged.
9. Install set screw in piston driver, torque to 12–15 lb-
ft. (16–20 N•m).
On 3.90 ratio models only, a washer (P/N 210288) must be
used between the piston driver and piston. Failure to install
the washer will cause engagement and disengagement
problems in the differential lock.
10. Trial fit, install piston cover assembly. Hand tighten
cap screws.
11. Screw in manual engagement screw, by hand
approximately 1 inch or until snug fit (light resis-
tance pressure is felt) both clutches must be com-
pletely engaged.
12. Remove manual engagement screw, clutches must
completely disengaged. Repeat above procedure if
clutches not completely disengaged.
Note: Fork adjustment is correct when curvic clutch teeth are
fully engaged with the fork free when moved by hand.
When air pressure is released or the manual bolt is
removed, the shift assembly should disengage freely.
13. When adjustment is complete, torque fasteners to
28–35 lb-ft. (38–47 N•m).
14. Install selector switch in cylinder cover. Torque
switch to 10–12 lb-ft. (14–16 N•m).
15. Check selector switch operation. Check switch elec-
trically with an ohmmeter or continuity tester. Switch
should close (show continuity) when clutches are
engaged and should open (no continuity) when
clutches are disengaged.
.030"
CAUTION
Fo
rward Assembly