K12559671

Solution K12559671
Thursday, May 3, 2018 7:23:51 PM CEST
NA_MACK_Vehicle_Range
NA_MACK_Vehicle_Ran
ge
Anthem , CHU , CXU , GU , M746 , M748 , Granite , TD
NA_VOLVO_Vehicle_Range
NA_VOLVO_Vehicle_Ra
nge
VNR , VNX , VNL , VNM , VHD , VAH
Engine family
Engine family
Volvo , Mack
Emission Standard
Emission Standard
2018 , OBD2017 , US17 GHG , US16 , US15 , US13 OBD , US14 GHG
** SOLUTION **
Title (customer effect)
Oil Contamination Of The Clutch Due To Rear Crankshaft Adaptor O-ring Leakage Oil Leak At Clutch And Flywheel Housing; Possible Burnt Clutch Smell And/Or Clutch
Slipping; Possible Customer/Initial Report Of Crankshaft Rear Main Seal Leak - OBD13
And Newer (16-Pin Diagnostic Connector)
Cause
Vehicles may present with oil leak coming from the clutch/flywheel housing and
observation of burned clutch smell or clutch slipping. These symptoms can be mistaken
as a crankshaft rear main seal leak.
Solution
Overview
The o-ring that seals the rear crank gear flange to the crankshaft can leak oil into the cavity on
the rear of the crank. This oil builds up and leaks out under the bolt heads of the flywheel and
contaminates the clutch. The oil in the flywheel/clutch housing will be black like engine oil
and the evidence of the leak will be all the way around the housing due to the oil being slung
out of the clutch assembly. When the source of the leak is the crankshaft rear main seal or a
tranmsission seal, oil will run down the face of the engine or the transmission and pool in the
bottom of the housing. Oil will not be distributed all the way around the housing as it would
from the rear crank gear flange o-ring.
Several examples of visual symptoms of this issue can be seen below (all pictures can be
clicked for full-size image):
Engine Oil Accumulation in Bottom of Flywheel Housing
Engine Oil on the Clutch Disk and Flywheel Bolt threads
Engine Oil Leak - Not from Main Seal - Note that there is no oil path visible from the bottom
of the crank flange down the face of the housing to the visible buildup
Oil Film visible on inner circumference of the Clutch Housing
Repair
A. This repair will require the removal of the flywheel housing in order to remove the rear
crank flange adaptor and replace the o-ring. An exploded diagram showing the o-ring can be
seen below:
Note that the O-ring is located under the Timing Gear assembly in Impact, not the
Crankshaft assembly.
- The procedure for flywheel housing removal and reinstallation can be found in the
Service tab of Impact, Operation 2125-03-02-03 Flywheel Housing, Replacement.
B. The clutch and pressure plate need to be replaced.
C. The flywheel should be cleaned and inspected, then resurfaced or replaced as necessary.
- Flywheel resurfacing guidelines can be found in the service tab of Impact, Function
Group 216: FSB 216-002 Flywheel Resurfacing Guidelines
- If the flywheel is blued on the back side, it must be replaced. Refer to the guidelines
above to assist with assessment.
Solution visibility
Dealer distribution
Function(s)/component(s) affected
Function affected
engine lubrication , automatic transmission , engagement
Function Group
Function Group
2153 Timing Gear , 216 crank mechanism , 41 clutch
Customer effect
Main customer effect
odour , fluid , road behaviour , slipping
Fluid problem
leak
Fluid implicated
oil
Road behaviour
driveability
Visual appearance
leaking
Conditions
Vehicle operating mode
when driving
Vehicle load
half laden , unladen , fully laden
Frequency of occurrence of
problem
always
Vehicle mileage
new , less than 50,000 km
Location of problem
underneath cab
Administration
Author
UT9268H
Dealer ID
UT9268H
Last modified by
RU4469V
Creation date
27-03-2018 16:03
Date of last update
10-04-2018 20:04
Review date
27-03-2019 00:03
Status
Published
NA_Reviewer
ut9268h
NA_Author_Group
GTT