Procedures I thru IX
I. Noise When Load on Backrest Frame Changes (Model 203, 204, 209, 211, 219)Note:
Also perform if work is being performed on any of the following:
^ Backrest frame (91A41 or 91N41)
^ Backrest cover (91A15, 91N15) or
^ Head restraint guide rail (91A33, 91N33)
These actions must always be performed if the backrest frame is exposed to avoid follow-up repairs.
Note:
Even if just one of the conditions exists, you should always implement the other measures (i.e. measures a, b, c, and d) regardless of whether or not the customer complains of these.
a. Noise from Lumbar Support in Backrest during Cold Temperatures
1. Verify noise during cold temperatures.
2. Remove backrest cover. Refer to WIS document AR91.10-P-1910P (203, 209), AR91.10-P-1910CW (204), AR91.10-P-1910T (211 up to MY05), AR91.10-P-1910TB (211 as of MY05) or AR91.10-P-1910TX (219).
3. Check if the guide wires are damaged (Figure 1) at the interface with the lumbar support basket.
Note:
Figure 2 shows the seat backrest frame with the seat cover and seat pad removed for clarity, it is not necessary to remove these parts to inspect and lubricate the guide wires.
4. If there is minor damage to the guide wires, apply lubrication (A000 989 36 60) to the guide wires.
5. In the case of major damage to the guide wires (Figure 3), sand down the guide wires of the padding support grid, wrap felt tape (A001 983 51 10) around them and apply lubricant (A000 989 36 60).
b. Padding Support Grid Rubs on Attachment Points on Backrest Frame (Models 164, 203, 209, 211, 219 and 251 produced up to 09/2005)
1. With backrest cover still removed, remove side bag.
2. Disconnect padding support grid from the four suspension points (Figure 4), two on the right side and two on the left side.
3. Cut four pieces of felt, approximate size is 25 mm by 2 mm. Apply lubrication (A000 989 36 60) to the felt and then adhere the felt to the suspension points of the padding support grid (Figure 5).
4. Reconnect the padding support grid to the four suspension points (two on the right and two on the left).
c. Relative Movements Produce Noise at Bottom of Backrest
(Models 203.740/747/764 only & 209.356/365/372/375/376/377/456/465/472/475/476/477)
1. Backrest cover is still removed and the seat is in installed position.
2. Detach seat cover and spray the rivets (Figures 6 and 7) in area between side section of frame and cross member with grease (A002 989 06 51).
d. Noise from Backrest Under Load Due to Incorrect Positioning of Circlip (Models 211, 219 only)
1. Check if the alignment of the circlip on the head restraint guide sleeve is correct (refer to Figure 8).
2. Reattach the seat cover and backrest cover then check that the noise does not occur again.
e. Noise from Seat Backrest (Models 203, 209 and 219)
Apply felt (A126 782 01 97) to seat back lining bracket so the bracket does not rub against the backrest frame. Refer to Figure 9 (inside backrest frame) and Figure 10 (backrest frame)
f. Seat Frame Noises (Model 204):
1. Noises from area of backrest:
a) Lubricate wire frame connection to side mountings (Figures 10a and 10b) with special lubricant (A000 989 36 60) included in Noise Kit (use damage code 91A41 36 for left seat, 91N41 36 for right seat).
b) In vehicles with manual lumbar adjustment, the wire frame could be displaced far enough to where the wire frame rubs against the lumber support (Figure 10c). Correct the displacement, and insert cable ties (A004 997 98 90) to prevent any further displacement (Figure 10d).
2. Noises from the area of the seat adjuster:
a) Adjust seat height to the highest position. Lubricate the crash lock as shown in Figure 10e with lubricant A002 989 07 51 (included in Noise Kit) (use damage code 91A27 36 for left seat and 91N27 36 for right seat).
b) Move the seat fore/aft adjustment to the rear, lift the inclination adjustment spring with a screwdriver as illustrated in Figure 10f and lubricate the spring with lubricant A002 989 07 51 (included in Noise Kit) as shown in Figure 10g (use damage code 91A27 36 for left seat and 91N27 36 for right seat).
II. Noise Between Seat Frame Brackets and Seat Cushion Frame Model 203 (up to VIN A903977, F817832 and R230819), Model 211 (up to VIN A967489 and X207037) and Model 219 (up to VIN A075885)
Note:
Also perform the action if you are performing work on the seat adjuster (91030, 91A27, 91N27) When the brackets are exposed during the work, the remedial action must be performed depending on the VIN range to prevent follow-up repairs.
The seat frame brackets rub on the seat cushion frame and if there are burrs on the brackets, this may make noise.
1. If burrs are visible (Figure 11, circles), proceed as follows.
2. Remove the seat, refer to WIS document AR91.10-P-1000P (203), AR91.10-P-1000T (211) or AR91.10-P-1000TX (219).
3. Remove the brackets and replace with new brackets.
Note:
Always install new micro-encapsulated bolts.
4. Reinstall the seat, refer to WIS document AR91.10-P-1000P (203), AR91.10-P-1000T (211) or AR91.10-P-1000TX (219).
III. Noise from Lower Trim Cover (Models 211 and 219 only)
The rib on the back side of the lower trim covers at the front of the seat cushion may cause a noise as it rubs on the seat cover.
1. Remove trim cover (Figure 12). Refer to WIS Document AR91.10-P-1200T.
2. Line side of trim cover rib (Figure 13) with felt (A001 983 51 10).
3. Reinstall trim cover (Figure 12). Refer to WIS Document AR91.10-P-1200T.
4. Confirm that the noise is no longer present
IV. Noise Between Seat Cover and Cover of Sidebag (Models 211 and 219 only)
The hard edge of the sidebag cover may make a noise as it rubs against the seat cover.
1. Remove side airbag.
2. Apply special sliding compound (A000 989 36 60) from the inside on the cover of the side airbag close to the graining (Figure 14)
3. Confirm that the noise is no longer present
V. Rubbing Noise Between Seat Cushion and Trim Cover (Model 211 with sport package only)
Rubbing noise where the seat cover contacts the trim cover (Figure 15, arrows)
1. Tilt the backrest rearward.
2. Apply special sliding compound (A000 989 36 60) to the inside of the trim cover (Figure 15, arrows).
3. Confirm that the noise is no longer present.
VI. Noise from CAK Module in Head Restraint (Models 203, 211, 219, 221 produced up to calendar week 41/06)
For vehicles produced before calendar week 41/6 and/or continuing complaints from the head restraint, replace the head restraint but not the guide sleeves (Figure 16).
VII. Noise from Right or Left Front Seat Backrest (Model 204 excludes AMG Models)
1. Install new padding with colored anti-creak coating. Refer to WIS document AR91.18-p-1820cw.
2. Remove fleece bag shown in Figure 17. Refer to WIS document AR91.18-p-1820cw. Do not reinstall fleece bag.
VIII. Noise during manual lumbar support adjustment (Model 164, 251)
The Bowden cable of the manually adjustable lumbar support may rub against the spring core of the backrest.
1. Remove seat-back lining Refer to WIS document AR91.10-P-1915GZ (164) and AR91.10-P-1915RT (251).
2. With a load on the backrest (e.g. a person sitting in the seat), adjust the manual lumbar support and determine the points at which the Bowden cable rubs against the spring core (possible locations illustrated in Figure 18).
3. Apply felt tape to the areas on the spring core that are rubbing on the Bowden cable.
4. Confirm that the noise is no longer present.
IX. Creaking/Squeaking noises during seat adjustment (Model 216, 221)
Inadequate lubrication or wire frame rubbing in seat cushion.
1. Lubricate seat rails as per DTB P-B-91.10/147 (or later version).
2. Lubricate seat cushion guide in the back of the cushion
a. Move seat fore/aft adjuster all the way to the front
b. On both sides of the seat, move seat cushion to the side, and lubricate plastic guide (as shown in Figure 19 and Figure 20) with grease spray A000 989 35 60 (included in Noise kit)
3. Lubricate seat cushion guide in the front of the cushion
a. Disassemble left and right side seat trim as per WIS document AR91.10-P-1200SX.
b. Lubricate both plastic guides (Figure 21) as shown in Figure 22 with lubricant A002 989 07 51 included in Noise Kit.
c. Spay grease A000 989 35 60 (included in Noise kit) in both plastic guides as shown in Figure 23.
4. If noises still persist in the area of the seat cushion, this may be caused by the wire frame rubbing on the cushion shell. To remedy, remove the seat cushion as per WIS document AR91.10-P-3310SX. Check cushion shell for chafe marks (refer to Figure 24) and apply felt in affected areas (use damage code 91A03 22 for the left seat and 91N03 22 for the right seat).