Drivetrain - 4-Matic Drive(R) System Information
Date: February 4, 2008Order No.: P-B-28.00/07a
Supersedes: P-B-28.00/07 dated January 16, 2007
Group: 28
Revision History
Revision Date Purpose
a 2/4/08 Transfer Case Repair Assembly Revised and Parts Information Updated
- 1/16/07 Initial issue
SUBJECT:
Model 221.186, Equipped with Transmission 722.96 4-Matic
All Model Years
Introduction of 4-Matic Drive
During the launch phase of new 4-Matic all-wheel drive system with transmission NAG2 722.96 (with integrated transfer case) used in Model 221 S550 4-Matic, the workshop must clarify before-hand whether the customer reported drive performance involving the main transmission NAG2 or the below 4-Matic specific components.
^ Integrated transmission / transfer case assembly
^ Front drive-shaft
^ Front axle differential
^ Front axle shaft
Possible reported conditions include shuddering/vibrations, howling transfer case and/or leaks at the front axle differential or transfer case.
Note:
To enable you to recognize and forward problems regarding transmission 722.96 with 4-Matic quickly, the 4-Matic diagnosis sheet (shown above) must be filled out completely and accurately. It must be returned with the related part and a copy of the form saved in the customer file.
Repair Concept
Until notified, no repair work should be performed on the following 4-Matic specific components (replacement only).
^ Transfer case assembly - Leaks in the sealing flanges must be resealed.
^ Front propeller shaft
^ Front axle differential
^ Front axle shaft
Note:
In cases of the above mentioned parts, the completed 4-Matic diagnostic form (previously shown) must be included with the incoming parts and a copy retained in the customer file. Failure to comply may result in a charge back.
Note:
All repair procedures which are authorized for the NAG2 are authorized for the NAG2 4-Matic as well.
Diagnostics can be performed, as outlined in the EDAC diagnostic tree and all standard repairs for the NAG2 may be performed. The axial play between the park pawl gear and grooved ball bearing, described in WIS AR27.50-P-0600-06SYZ, must be measured and recorded before the main transmission NAG2 is disassembled or repaired. During assembly, the axial play must be set again using shims. If the axial play is not set correctly, transmission noises or further transmission damage will occur.
If diagnostic procedures lead the technician to the replacement of a valve body or transmission, a WSG preauthorization form must be completed as described in DTB P-B 27.00/38d dated November 7, 2006.
Software Update - Flashing
If the transmission control module needs to be programmed, only STAR DIAGNOSIS versions 09/2006 or later should be used in conjunction with all of the related add-ons.
Note:
It is important to ensure that only "SDflash Release" CDs as of 9/2006 be used with all of the related add-ons.
Parts Information