SP16-321

Special Bulletin
Date

Expiration

Release

Page

09.2016

09.2018

0

1(7)

NYCT IDLER BEARING REPLACEMENT

Prevost vehicles
DESCRIPTION
On the vehicles affected by this bulletin, proceed to the replacement of the original A/C tensioner and
alternator idler bearings with a FAG branded unit following the procedure outlined below.
These FAG bearings are of heavier duty construction and will offer extended durability compared to the
original ones.
MODEL YEAR(S) AND VEHICLES INVOLVED
NOTICE TO SERVICE CENTERS
Verify vehicle eligibility by checking warranty bulletin status with SAP or via ONLINE WARRANTY
SYSTEM available on Service / Warranty tab of Prevost website.
Model

VIN

X3-45 Commuter

The following individual vehicles:
2PCG33495EC735590, 2PCG33498EC735602
From 4RKG33497F9737001 up to
4RKG33491G9737299 incl.

Model Year : 2014 - 2016

Fleet Number

From 2490 up to
2789, incl.

This bulletin does not necessarily apply to all the above-mentioned vehicles, some vehicles may have been modified
before delivery. The owners of the vehicles affected by this bulletin will be advised by a letter indicating the Vehicle
Identification Number (VIN) of each vehicle concerned.

MATERIAL NEEDED
Order the following parts:
Part No.
507014

Description
Bearing FAG, 20 x 52 x 22.2

Qty
2

Other parts that may be required:
Part No.

Redact:

Description

Qty

504095

Snap Ring, Int. 2.00 x 2.12 x 0.62

As req.

457502

Alternator Idler pulley (without bearing)

As req.

457504

A/C Tensioner pulley (without bearing)

As req.

457501

Tensioner Back Spacer

As req.

053690

Idler Bushing

As req.

453076

Dust cap

As req.

MG

SP16-321

Special Bulletin
Date

Expiration

Release

Page

09.2016

09.2018

0

2(7)

NOTE
Material can be obtained through regular channels.

PROCEDURE

DANGER
Park vehicle safely, apply parking brake, stop engine. Prior to working on the vehicle, set the ignition
switch to the OFF position and trip the main circuit breakers equipped with a trip button. On Commuter
type vehicles, set the battery master switch (master cut-out) to the OFF position.

PART 1 REMOVING IDLER PULLEYS FROM THE VEHICLE
1.

Open the vehicle rear engine door and locate the two pulleys (A/C tensioner # 457505 and
alternator idler # 457705) requiring the bearing replacement (Fig.1).

FIG.1 ALTERNATOR IDLER AND A/C TENSIONER PULLEY

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SP16-321

Special Bulletin

2.

Date

Expiration

Release

Page

09.2016

09.2018

0

3(7)

Release belt tension from the two A/C V-belts by loosening the A/C belt tensioner (Fig.2)

FIG.2 A/C BELT TENSIONER

-

Slightly loosen tensioner locking bolt (A) to allow up and down movement.

-

Unscrew the tensioner adjusting bolt (B) to remove tension applied to the belts.

3.

Remove the two belts from the A/C compressor and tensioner pulleys.

4.

Using a rubber mallet, gently tap off the A/C idler pulley dust cap.

5.

Unscrew the A/C idler pulley center retaining bolt (C) and remove the idler pulley (Fig.2).
NOTE: Be cautious not to lose the spacer behind the pulley (as seen in Fig.7).

6.

Insert a 1/2" ratchet into the alternators automatic belt tensioner opening and twist the tensioner
arm to slacken the alternator belt (Fig.3).

FIG.3 1/2" RATCHET USED TO TWIST TENSIONER ARM

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Date

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Page

09.2016

09.2018

0

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7.

Slip the belt off the two alternator pulleys.

8.

Using a rubber mallet, tap off the lower alternator idler pulley dust cap (lower pulley on Fig.1).

9.

Unscrew the alternator idler pulley center retaining bolt and remove the idler pulley.
NOTE: Be cautious not to lose the spacer and washer (Fig.5) behind the bolt head.

PART 2 BEARING REPLACEMENT
NOTE: Procedure to remove and replace bearings is identical for both pulleys. Refer to Figure 4 below for
installation.

FIG.4 A|C TENSIONER AND ALTERNATOR IDLER BEARING REMOVAL / INSTALLATION

1. Remove the pulley inner snap rings using appropriate snap ring pliers.
2. Using a suitable bearing removal tool, press off the bearing out of the pulley assembly.
3. Still using suitable tools, insert a new bearing # 507014 into the pulley body until it bottoms out in the
pulley body.
4. Reinstall the snap rings.

Redact:

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SP16-321

Special Bulletin
PART 3 PULLEYS REINSTALLATION
1.

Date

Expiration

Release

Page

09.2016

09.2018

0

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Reinstall the alternator idler pulley on the vehicles as per Fig.5 below. Center bolt must be torqued to
74 lb-ft. Apply yellow torque seal to the bolt head once completed (Fig.5).

FIG.5 ALTERNATOR IDLER PULLEY INSTALATION

2. Put back the center dust cap over the idler pulley using a rubber mallet to avoid cap deformation
(Fig.5 above).
3. Insert a 1/2" ratchet into the alternators automatic belt tensioner opening (Fig.6).

FIG.6 1/2" RATCHET USED TO TWIST TENSIONER ARM

4. Twist the tensioner arm and slide the alternator belt under the tensioner pulley (Fig.6).
5. With the wrench still holding the tensioner arm, pass the belt over the two alternator pulleys.
6. Release the tensioner arm to apply pressure to the belt (tensioner is automatic, no further belt
adjustment is necessary).

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Date

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09.2016

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7. Reinstall the A/C idler pulley on the idler body, torque center bolt to 35 lb-ft and add yellow torque
seal stripe to the bolt head (Fig.7).

FIG.7 A/C TENSIONER PULLEY INSTALATION

8. Put back the center dust cap over the idler pulley using a rubber mallet to avoid cap deformation.
9. Slide the two A/C belts in the idler and compressor pulley grooves.
10. Belt tension is applied through the tensioner adjustment screw (B). Tighten until the belts are under
correct tension (Fig.8). Belt tension should be within the following values*:

New belts: 90-100 lbs.
Used belts: 75-85 lbs
*Check belt tension using a belt strand
tension gauge.

FIG.8 A/C BELTS TENSION ADJUST.

11. Once correct value is achieved, tighten lock screw (A) to 43 lb-ft and add a stripe of yellow torque
seal to the bolt head (Fig.8).
12. Once adjustment is completed, set the battery master switch (master cut-out) to the ON position, start
the vehicle and allow the engine to run for about ten minutes. Check belt tension and adjust as
required.
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SP16-321

Special Bulletin
Date

Expiration

Release

Page

09.2016

09.2018

0

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PARTS / WASTE DISPOSAL
Return replaced parts to Prevost with A.F.A. for full reimbursement.
Discard waste according to applicable environmental regulations (Municipal/State[Prov.]/ Federal)

ESTIMATED TIME
The time required to perform this special bulletin is approximately 0.75 (3/4) hour.
OTHER
OTHER
VBC Bulletin

N/A

Fail Code

01.01

Defect Code

09

Syst. Cond

B

Causal Part

507340

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Prevost engages in a continuous program of testing and evaluating to provide the best possible product. Prevost, however, is not
committed to, or liable for updating existing products.

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