K10216390

Solution K10216390
Monday, June 3, 2019 7:09:39 PM CEST
** SOLUTION **
Title
** Tech Tip ** - TT-019-2016 Automated Manual Transmission ( AMT ) Bearing And
Gear Shaft Inspection
Mack Models
AN - Anthem , CHU - Pinnacle, Axle back , CXU - Pinnacle, Axle front , GR - Granite
Mack Model
, GU - Granite , PI - Pinnacle , TD - Titan
Volvo Models
VNL , VNM , VNR , VNX , VAH , VHD , VT
Volvo Model
Engine family
Engine family
11L Engine , 13L Engine , 16L Engine , MP7 , MP8 , MP10
Transmission
Transmission
AMT-F With Crawler Gears , AMT-F Without Crawler Gears , AMT-C , AMT-D , A
MT-F , AMT-C , AMT-D , AMT-F With Crawler Gears , AMT-F Without Crawler
Gears
** SOLUTION **
Cause
The customer has a driveability complaint for the vehicle bucking, slipping, or engine
surging when in reverse.
Soluti
Codes associated with this complaint:
on
P1071- Split Engagement System, FTB 96 Unintentional disengagement of direct split
P1057- Main Shaft Speed Sensor, FTB 21 Data valid but below operational range
Most probable cause:
Loss of main shaft pre-load from a spigot bearing failure
Recommended Actions: Review pictures and perform instructions below
Towing Related Failure (Image 1)
Towing Related Failure (Image 2)
Spalled bearing failure (Image 3)
Spalled bearing race (Image 4)
Additional checks:
Reviewing DTC readout can be helpful in determining spalled vs. towing damaged spigot bearing. Main shaft
speed codes prior to any towing event can indicate that the loss of main shaft pre-load may have begun before
the truck was towed to the shop. This means that the bearing started to spall before the unit was towed
improperly.
Spalled Bearing Failure (Image 5)
Spalled Bearing Race (Image 6)
These images (5 & 6) represent a failure that went ignored for some time.
While the main shaft does not have evidence of heat as in the towing example (image 1), there are additional
parts that have been affected:
• Contact with the main shaft nut
• Rollers missing and race worn down
• Oil distribution tube twisted off and closed
• P1 bearing damaged
• Split synchro ring broken
Clues that this may have been a spalled, or otherwise damaged, spigot bearing is:
1. The ridge in the input shaft. This is similar to what is seen in the spalled spigot bearing failure image 3.
2. The DTC readout, as in the example below. The vehicle clock is incorrect however you can assume that the
"Last Occurrence" has to be close to the readout day. In this example you can see that there had been main
shaft codes for ~2 mo and split shift codes for ~3mo
Code Description:
P1071- Split Engagement System, FTB 96 (FMI 1) Unintentional disengagement of direct split
Fault Condition:
High split jumps out
The split cylinder valves are inactive
Possible Symptom:
Yellow lamp is illuminated
Loss of torque
Possible Cause:
N/A
P1057 (PID 160) Main Shaft Speed Sensor, FTB 21 (FMI 1) Data valid but below operational range
Fault Condition:
The sensor signal is within normal range and, the main shaft speed differs from both the value of the
countershaft speed and the vehicle speed received from the vehicle ECU. The following conditions must be
fulfilled for a time of 2.0 seconds in order to activate:
A gear (not neutral) is engaged in the transmission
The value of the input shaft speed calculated from the main shaft speed sensor (SESM) is more than
300 rpm
The value of the input shaft speed calculated from the counter shaft speed sensor (SESC) is more than
300 rpm
Possible Symptom:
Yellow lamp is illuminated
Slow gear changes
Rough gear changes
Possible Cause:
N/A
Solution visibility
Dealer distribution
Function(s)/component(s) affected
Function affected
TT
, engagement , Input Shaft , Main Shaft , Front Housing (Gearbox)
Function Group
Function Group
431 gearbox, manual
Customer effect
Main customer effect
judder , slipping
Fault Codes And Error Codes
OBDII Diagnostic Trouble
Codes (P, U, B Format)
P1057 , P1071
Conditions
Vehicle operating mode
acceleration , in reverse , engagement , during engagement
Administration
Author
ut01793
Last modified by
RU4469V
Creation date
10-11-2016 21:11
Date of last update
30-05-2019 16:05
Status
Published