LI27 50-P-064440

7G-DCT: Scratching noise when changing
gear from D to R when transmission cold.
Topic number
LI27.50-P-064440
Version
8
Function group
27.50 Gear assembly
Date
07-16-2018
Validity
All vehicles of BR 176, BR 117, BR 156, BR 242, BR 246
with transmission 724.0
Reason for change
Information for repairs, valid for all vehicles, added. Special tool for repair of transmission A 246 370 70 03 now
available.
Reason for block
Complaint:
Scratching noise when changing gear from D to R with the transmission cold.
Attachments
File
Description
Kratzen in R.mp3
Scratching in R at second 14
Cause:
Possibly the Synchronizer ring of reverse gear
Check whether the vehicle is affected by the scratching noise:
Accelerate the cold vehicle to 18mph (2nd gear must be engaged).
Slow the vehicle with the brakes and at 4mphselect reverse gear.
Remedy:
Information for repairs, valid for all vehicles:
•
•
•
•
The oil pump gear must be replaced at the same time, otherwise initial damage to the oil-pump drive shaft can
occur.
Caution when removing the oil pump gear: The mounting nut has a left-hand thread. Do not use an impact
wrench or compressed-air tool, otherwise the shaft of the primary oil pump and the special tool will be damaged.
Assembly: Before installing the oil pump gear, the shaft of the primary oil pump and the contact surface between
the nut and the pump gear must be cleaned of all grease and oil.
It is not absolutely necessary to remove the oil pump when replacing the output shaft.
07-16-2018 3:28 PM
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AMG vehicles:
Remedy for 724.015 (prior to facelift):
•
Order and replace output shaft (3rd, 6th, 7th and reverse gear) A 246 260 95 00. Make sure that the oil restrictors (A 246 372 18 50) are installed in the output shaft; if not, order them at the same time. When assembling the transmission, make sure that the shift valve 56 (absolute pressure valve) in picture B for the park pawl
(AR27.10-P-0510NKB) is installed correctly. If the valve is installed the wrong way round, the park pawl will be
damaged due to pressure spikes.
•
Valid for transmission variants:
•
Transmission A 246 370 63 02 (FBS3 + VGS1)
•
Transmission A 246 370 57 02 (FBS3 + VGS2)
•
Transmission A 246 370 40 02 (FBS4 + VGS2)
Remedy for 724.016 (as of facelift):
•
Order output shaft (3rd, 6th, 7th and reverse gear) A 246 260 27 01. Make sure that the oil restrictors (A 246 372
18 50) are installed in the output shaft; if not, order them at the same time. When assembling the transmission,
make sure that the shift valve 56 (absolute pressure valve) in picture B for the park pawl (AR27.10-P-0510NKB)
is installed correctly. If the valve is installed the wrong way round, the park pawl will be damaged due to pressure spikes.
•
Valid for transmission variant:
•
A 246 370 54 03 (without lock)
•
A 246 370 70 03 (with lock, code 471, 37A) The special tool (SWZ) W724 589 00 16 00 for spinning and
calibrating the differential under preload is now available and can be ordered. It is no longer necessary to
replace the transmission. The adapter is then only to be inserted into the special tool W 724 589 02 31 00
in place of the driver in the current description. The function for spinning is identical to that already described. The WIS document is being amended.
Series production vehicles:
•
•
Remedy for vehicles , prior to 04/2017
Using the full VIN, check the part number of the output shaft (3rd, 6th, 7th and reverse gear) in the EPC. If one
of the following part numbers is listed, the output shaft must be replaced. Order corresponding output shaft.
•
Output shafts:
- A 246 260 67 20
- A 246 260 68 20
- A 246 260 69 20
- A 246 260 70 20
- A 246 260 84 00
- A 246 260 85 00
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•
If none of these part numbers is listed in the EPC, the transmission must be replaced in the event of complaints.
Symptoms
Power transmission / Automatic transmission / Function / Engaging process
Power transmission / Automatic transmission / Drive position selection / Noises / Scratching
Power transmission / Automatic transmission / Noises / Noise
Parts
Part number
ES1 ES2 Designation
Quantity Note
EPC
A 246 260 27 01
Output shaft
1
724.016
X
A 246 260 95 00
Output shaft
1
724.015
X
A 246 260 69 20
Output shaft
1
724.021,724.011, 724.004
X
A 246 260 70 20
Output shaft
1
724.001
X
A 246 260 68 20
Output shaft
1
724.002 with code A69 (Carbon synchronization)
X
A 246 260 67 20
Output shaft
1
724.003 with code A69 (Carbon synchronizer), 724.020
X
A 246 260 85 00
Output shaft
1
724.003 with code 28A (Uprated synchronizer body) +A69 (Carbon synchronizer)
X
A 246 260 84 00
Output shaft
1
724.004, 724.011 with code 28A
(Uprated synchronizer body)
X
Operation numbers/damage codes
Op. no.
Operation text
Time
Damage
code
Note
27389 46
In the dealer text note please state
"Reverse gear scratching"
WIS-References
Document number
Title
AR27.10-P-0510NKB
Disassemble/assemble
transmission
Note
Allocation
Remedy
Validity
Vehicle
Engine
Transmission
A (176)
*
*
B (242, 246)
*
*
CLA (117)
*
*
GLA (156)
*
*
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