SECTION 01: ENGINE
18
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
3. AUTOMATIC BELT TENSIONERS AND
IDLER PULLEYS INSPECTION
With the engine running, if noise is coming from
the tensioners or drive system, an inspection
with the engine off is necessary.
MAINTENANCE
Remove belts and inspect automatic belt
tensioners, idler pulley bearings every 30 000
miles.
FIGURE 14: IDLER PULLEYS AND AUTOMATIC BELT
TENSIONERS ON COOLING FAN DRIVE, WATER PUMP
DRIVE AND A/C COMPRESSOR DRIVE
I
DLERS
Ref
System
Torque lbs-ft
I-1
cooling fan drive
50
I-2
cooling fan drive
35
I-3
cooling fan drive
50
I-4
water pump drive
43
I-5
water pump drive
16 (pulley)
32 (shaft)
I-6
A/C compressor drive
35
I-7
A/C compressor drive
82
I-8 alternator
drive
82
AUTOMATIC BELT TENSIONERS
Ref
System
Torque lbs-ft
T-1
cooling fan drive
32 (2x)
T-2
water pump drive
43
T-3 alternator
drive
43
3.1 BEARING INSPECTION
1. First, set parking brake, turn the ignition
OFF and set the rear start selector switch to
the OFF position.
2. Remove all belts on cooling fan drive, water
pump drive, A/C compressor drive and
alternator drive.
FIGURE 15: IDLER AND AUTOMATIC BELT TENSIONER
ON ALTERNATOR DRIVE
3. Spin all idler pulleys, I-1 thru I-8, plus the
idlers that are part of the automatic belt
tensioners T-1 thru T-3.
4. Listen if some idlers are noisy and check for
play in the bearings by hand.
5. Replace noisy idlers or if a play is found.
Replace the automatic belt tensioner as a
complete unit.
6. Record the results of the inspection.
3.2 AUTOMATIC BELT TENSIONER
BUSHING WEAR
Automatic belt tensioner bushing wear may
results in belt misalignment.
1. Check the automatic belt tensioner T-1 thru
T-3.
2. Pry the automatic belt tensioner arm and
check for a play between the arm and the
spring case (see image below).
