FSB 237-020rev

Mack Trucks
Greensboro, NC USA
Field Service Bulletin
Trucks
Date
9.2017
This Field Service Bulletin replaces bulletin “Unit Injector Yoke Hold-Down
Bolt Torque Specification“, (USA139276034) PV729–FSB237-020_M, dated
06/2017.
Group
No.
Release
Page
237
020
02
1(1)
Unit Injector Yoke Hold-Down Bolt Torque
Specification
CHU, CXU, GR, GU, PI
FSB 237-020, Unit Injector Yoke Hold-Down Bolt
Torque Specification
(September 2017)
MACK CHU, CXU, GR, GU, and PI trucks built from 2009 to 2017 and equipped with MP7,
MP8, and MP10 engines (EM-USA10, EM-USA14, and EM-USA17), will require a new
torque specification for the Unit Injector Yoke Hold-Down Bolt. Effective immediately, the
torque value in step 4 has changed to 25 +5/-0 Nm (18 +4/-0 ft-lb). See the torque procedure
in steps 1 through 5 below. Additionally, the new yoke hold-down bolt torque will be updated
in all service procedures, methods, and specification manuals.
Note: If the unit injector yoke hold-down bolts are removed, do not reuse. The unit injector
yoke hold-down bolts are made for one time use only.
Note: This bulletin does not apply to MACK Trucks Australia.
W2124666
Unit Injector Yoke Hold-Down Bolt Torque Procedure
1 Tighten 20 +5 Nm (15 +4 ft-lb).
2 Tighten 180 ±5 degrees.
3 Loosen the bolt until the torque is 10 to 15 Nm (7 to 11 ft-lb), back off approximately 150 Degrees.
4 Tighten 25 +5/-0 Nm (18 +4/-0 ft-lb).
5 Tighten 90 ±5 degrees.
USA139451068
PV729-FSB237-020_M