SECTION 06: ELECTRICAL
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version) – Sec 06 revised June 2017
39
5. BOSCH
ALTERNATORS
Two 28 volt 150A, self-regulated, belt driven, air-
cooled HD 10 Bosch alternators are used in the
24 volt electrical system.
If the alternators needed to be removed, reinstall
as follows. Refer to Figure 36 for installation and
to Figure 37 for tightening specifications:
1. If necessary, tighten screws (6) fixing
alternators support assembly onto engine (1,
Figure 36). Torque tighten to 43 lbf-ft, use
some Loctite 243 blue (680038) onto the
threads. Also tighten screw (1) fixing belt
tensioner onto alternators support assembly
(1, Figure 36). Torque tighten to 43 lbf-ft,
use some Loctite 243 blue (680038) onto
the threads.
2. If removed, reinstall screw (1) fixing
alternators support assembly onto engine (2,
Figure 36). Torque tighten to 22 lbf-ft, use
some Loctite 243 blue (680038) onto the
threads.
FIGURE 35: ALTERNATORS DRIVE BELT
3. Mount the a/c compressor idler pulley onto
alternators support assembly (3, Figure 36).
Torque tighten to 150 lb-ft, use some Loctite
243 blue (680038) onto the threads.
4. Install alternators arched support loosely
onto engine. If removed, install alternators
idler pulley (4, Figure 36) onto alternators
arched support, torque tighten to 43 lb-ft.
FIGURE 36: TWIN ALTERNATORS INSTALLATION
5. Fix lower and upper alternators loosely to
alternators support assembly using bolts (5,
Figure 36). Also, mount the lower and upper
alternators onto alternators arched support.
If removed install stone guard below lower
alternator.
6. In order to assure installation, it is important
to tighten the alternator mounting bolts in the
following order (Figure 37).
1
st
nut a, 43 lbf-ft.
2
nd
nut b, 43 lbf-ft (2x).
3
rd
nut c, 80 lbf-ft (2x)
FIGURE 37: ALTERNATOR MOUNTING - TIGHTENING
SEQUENCE
7. Mount pulleys (6, Figure 36) onto
alternators. Torque tighten to 58 lb-ft.
8. Install alternators belt.
Note
Final tightening of the pulleys can be
performed once the belt is installed. This will
help keep the pulley from turning when
tightening.
