Seat - Noise/Vibration
File In Section: 08 - Body and AccessoriesBulletin No.: 99-08-50-004
Date: April, 1999
TECHNICAL
Subject:
Seat Noise/Vibration - Creak In Front Seat Cushion, Rattle/Vibration
In 40% Front Seat, Jingle In 20% Folding Center Seat (Replace Seat Components)
Models:
1999 Chevrolet and GMC C1/K1 Models (Silverado and Sierra) with Full Feature 40% front Seat, 20% Folding Seat (RPOs AN3, AE7)
This bulletin contains information on three conditions:
Condition # 1
Some owners of early production vehicles may comment about a creaking noise toward the rear of the front 40% seat cushion. This condition may be more pronounced when driving over bumps.
Cause
This condition may be caused by an excessive clearance where the seat cushion retainers meet the seat cushion pan.
Correction
New seat cushion retainers1 P/N 12473290, have been developed in order to correct this condition. Replace the seat cushion retainers on affected vehicles. Use the following procedure and the part number listed below.
1. Remove the front 40% seat cushion. Refer to steps 1-6 of the seat cushion replacement procedures in the Seats subsection in the 1999 Silverado and Sierra Service Manual.
2. Disconnect the electrical harnesses as necessary.
3. Pull out the rear plastic retainers (1) on the seat back while squeezing on the back side of the retainers. It is not necessary to remove the seat back nuts (2).
4. Install the new plastic retainers.
5. Connect the electrical harnesses as necessary.
6. Install the front 40% seat cushion. Refer to seat cushion replacement procedures in the Seats subsection in the 1999 Silverado and Sierra Service Manual.
Labor
0peratlon Description Labor Time
Use published
C6175 Spring, Seat Adjuster - labor
R&R or Replace
Condition # 2
Some owners may comment about a rattle noise or vibration coming from the 40% front seat. The condition may be more pronounced in the unoccupied passenger seat while the vehicle is moving side-to-side, such as in turns. The condition may also occur in the driver's seat, although the noise may be masked by the weight of the occupant. This condition may occur at any speed.
Cause
This condition may be caused by the power seat recliner thrust bearing that is too short.
Correction
A new power seat recliner, P/N 12475326 (passenger side) and P/N 12475325 (driver side), has been developed in order to correct this condition. Replace the appropriate power seat recliner on affected vehicles. Use the appropriate part number listed below. Refer to the Seats subsection in the 1999 Silverado and Sierra Service Manual for recliner replacement procedures.
Condition # 3
Some owners may comment about a "jingle" noise coming from the latch of the 20% folding center seat. The noise occurs while the seat is in the folded down position. The condition is more noticeable when the vehicle is driven over a bump. The condition may be more pronounced on the passenger side of the center seat.
Cause
This condition may be caused by excessive clearance at the latch pin of the center front seat.
Correction
A new latch assembly, P/N 12475347, has been developed in order to correct the condition. Replace the folding center seat latch assembly on affected vehicles. Use the following procedure and the part number listed below.
1. Move the front 40% seats to the full forward position.
2. Unfasten the J-clip in order to release the upper portion of the seat trim. This will expose the upper latch attachment bolts.
3. Remove the upper latch attachment bolts (7).
4. Remove the latch cover attachment screw (5).
5. Remove the upper latch cover (6).
6. Remove the free pivot TORX(R) bolt (2) from the left side of the seat frame.
7. Remove the folding center seat back (1) from the seat frame.
8. Remove the lower latch cover (4).
9. Remove the lower latch attachment bolts (3).
10. Remove the latch assembly (8).
11. Position the new latch assembly (8) on the center seat frame.
12. Install the lower latch attachment bolts (3).
Tighten
Tighten the bolts to 25 N.m (18 lb ft).
13. Install the lower latch cover (4).
14. Position the folding center seat back (1) on the seat frame.
15. Install the free pivot TORX~ bolt (2) to the left side of the seat frame.
Tighten
Tighten the bolts to 25 N.m (18 lb ft).
16. Position the upper latch cover (6) over the lower latch cover (4). Install the attachment screw (5).
Tighten
Tighten the screw to 3 N.m (26 lb in).
17. Install the upper latch attachment bolts (7).
Tighten
Tighten the bolts to 25 N.m (18 lb ft).
18. Fasten the J-clip in order to close the upper right portion of the seat trim cover.
19. Move the front 40% seats to the desired position.
Labor
Operation Description Labor Time
Latch, Front Seat Use published
C6705 Cushion Console - labor
Replace operation time
Parts Information
Parts are currently available from GMSPO.