PI-0850

Service Program
Trucks
Mack Trucks, Inc.
Greensboro, NC USA
SB-10055988-1521
Date
Group
No.
Release
Page
5.2014
721
001
01
1(7)
Front Axle Wedge, Installation
CHU
PI0850, Front Axle Wedge, Installation
(May 2014)
The front axle u-bolt wedges were installed incorrectly on some MACK CHU trucks built
between 11/11/2013 and 02/24/2014. The incorrect installation of the wedge caused the ubolts to bend on the front axle. Proper orientation of the wedge, replacement of the u-bolts,
and nuts will ensure the front axle u-bolts will not bend. See the table below for the new front
axle wedge installation parts, and then follow the installation procedures outlined in this
document.
Note: This bulletin does not apply to MACK Trucks Australia.
W7089864
Required Parts
Front Axle Wedge, Installation Parts
PV729-PI0850
Item
Qty
Part Number
Description
1
4
21391468
U-Bolt
2
8
21823706
Nut
3
2
N/A
Wedge
USA64790
Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
Front Axle Wedge Installation Procedure
You must read and understand the precautions and guidelines in Service Information,
group 70, "General Safety Practices, Frame, Springs, Shocks and Wheels" before
performing this procedure. If you are not properly trained and certified in this procedure,
ask your supervisor for training before you perform it.
DANGER
Do not attempt to repair or service this vehicle without having sufficient training, the correct
service literature and the proper tools. Failure to follow this could make the vehicle unsafe
and lead to serious personal injury or death.
1 Park the vehicle on a level surface.
2 Apply the parking brake.
3 Place the transmission in neutral or park.
4 Install the wheel chocks.
W7086748
5 Disconnect the cable from the battery’s negative terminal.
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Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
6 Remove the u-bolt (1), wedge (2) and nuts (3) from the front axle.
Note: Left side shown.
Note: Remove the u-bolts one at a time as shown in the figure below.
Note: Do not discard the existing wedge. Clean the wedge of any debris and store for
reuse.
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Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
7 Position the u-bolt, wedge and nuts on the front axle as shown.
Note: Use the existing wedge.
Note: Ensure the wedge is installed with the thick side facing rearward.
Note: Ensure the front axle locating features are utilized.
Note: Do not tighten the fasteners at this time. See the torque sequence chart after
installation of both U-bolts.
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Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
8 Tighten the fasteners to specification as shown in the u-bolt torque sequence table below.
W7089868
U-bolt Torque Sequence
Step
Tighten
Torque Specification
1
All four nuts in the cross pattern shown
40 Nm (29.5 ft-lb)
2
All four nuts in the cross pattern shown
135 Nm (99.6 ft-lb)
3
All four nuts in the cross pattern shown
250 Nm (184 ft-lb)
4
All four nuts in the cross pattern shown
350 Nm (258’1 ft-lb)
5
All four nuts in the cross pattern shown
550 Nm (405.7 ft-lb)
9 Repeat Steps 1–8 for the right side front axle wedge replacement.
10 Connect the battery cable to the negative (ground) terminal.
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Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
11 Remove the wheel chocks.
W7086759
Note: To signify that the campaign has been completed, using a permanent-type marker
(such as a Sharpie®) to write the campaign number (PI0850) and completion date in the
spaces provided on the Campaign Completion label located inside the cab as shown in the
illustration below. If a label is not already affixed inside the cab, apply a label (part No. TS897)
and supply the information as required. Campaign Completion labels are available in packs of
50 and can be ordered by faxing a completed BR313 to Pacesetters Business Services at
610-264-9465.
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Mack Trucks, Inc.
Service Program
Date
5.2014
Group
No.
Release
721
001
01
Reimbursement
This repair is covered by an authorized
Service Program. Reimbursement is
obtained through the normal claim handling
process.
UCHPReimbursement
eWarranty
Reimbursement
Claim Type (used only when uploading from
the Dealer Bus. Sys.)
B
B
Vehicle inspected, repair not required
1- Inspected OK
1- Inspected OK
Vehicle repaired per instruction
2- Modified per
instruction
2- Modified per
instruction
Primary Labor Code
7211–02–09–01
1.5 hrs
1311G–ZQ–96
1.5 hrs.
Time to take charge and determine campaign
status
1700–16–01–01
0.3 hrs
101AA–0A–00
0.3 hrs
Causal Part
8084707
8084707
SCC Code
S6572
N/A
Authorization Number
N/A
PI0850
Expiration Date
25-APR-2015
25-APR-2015
Recall Status
Labor Code
Note: Take Charge Time is not included in the Labor Code for this operation. Take charge
may be eligible but can only be used once per repair visit. If vehicle is having other warranty
repairs performed, take charge should be charged to the warranty repair, otherwise take
charge can be charged to this service program.
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