Rear Suspension - Knocking Noise
90chrysler13NO.: 02-08-90
GROUP: SUSPENSION
DATE: Nov. 5, 1990
SUBJECT: Rear Suspension Noise
MODELS:
1988-1991 C/AC - Dynasty/New Yorker Landau/Salon AY - Imperial/New Yorker Fifth Avenue
SYMPTOM/CONDITION:
On some 1988-91 C, AC, and AY models, a knocking noise or rattle may be coming from the rear shock absorber area.
DIAGNOSIS:
This noise may be a rear suspension pivot bushing to hanger bracket interference. Interference may be eliminated on some of the vehicles by adjusting the hanger brackets.
PARTS REQUIRED:
2 Pivot Bushings PN 4626026
REPAIR PROCEDURES:
This repair procedure is for the adjustment of the hanger brackets and/or replacement of the pivot bushings.
1. With the vehicle suspension at ride height, preferably on a drive-on hoist, loosen the six (6) hanger bracket to frame bolts.
2. Jounce the vehicle.
3. The hanger brackets sometimes will move inboard on their own or with a manual push. If the brackets have moved inboard, tighten the hanger bracket to frame rail bolts to 75 N-m (55 ft.lbs.) torque, while vehicle is still at ride height.
4. Road test vehicle.
5. If noise is still present, replace both pivot bushings.
For vehicles with or without load leveling suspension.
1. Raise vehicle.
2. Remove rear wheels.
3. Remove parking brake cables.
4. Remove brake line brackets.
5. Support trailing arms.
6. Remove lower shock nuts.
7. Remove track bar.
8. Remove rear coil springs.
9. Remove trailing arm hanger brackets from frame.
10. Remove hangers from the trailing arm.
11. Replace pivot bushings using Remover/Installer Special Tool C-4212-L (Press) and 3 piece set, Special Tool 6122 (Receiver Support Bridge, Bushing Remover/Installer and Bushing Remover).
12. Install hangers to the trailing arm.
13. Install trailing arm bracket to frame.
14. Install rear coil springs.
15. Install track bar.
16. Install lower shock nuts.
17. Connect brake line brackets.
18. Connect parking brake cables.
19. Install rear wheels.
20. Lower vehicle.
21. Road test.
The following procedure is unique for vehicles with automatic air suspension.
1. With vehicle positioned on hoist, lower the rear suspension using the DRB II, refer to the 1991 Air Suspension/Load Leveling Diagnostic Manual # 81-699-0130.
2. Disconnect negative battery cable.
3. Raise vehicle.
4. Disconnect the air lines to vent the rear air springs.
5. Disconnect parking brake cables.
6. Disconnect brake line brackets.
7. Support the trailing arms.
8. Remove trailing arm hanger brackets from the frame.
9. Replace pivot bar bushings using Remover/Installer Special Tool C-4212-L (Press) and 3 piece set, Special Tool 6122 (Receiver Support Bridge, Bushing Remover/Installer and Bushing Remover).
10. Connect brake line brackets.
11. Connect parking brake cables.
12. Connect air lines.
13. Recharge the air springs, prior to lowering to avoid pinching the air bag. Refer to the 1991 Front Wheel Drive Car Service Manual, Publication # 81-270-1101, page 2-80, for recharging procedure.
14. Lower vehicle.
15. Connect negative battery cable.
16. Road test vehicle.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No. 02-30-07-90 . . . . . . . . . . . . . . . . 0.3 Hrs.
Adjust Rear Trailing Arm Hanger Brackets
02-30-07-91 . . . . . . . . . . . . . . . . 1.5 Hrs. Adjust Hanger Brackets And Replace Pivot Bushings (with or without Load Leveling)
02-30-07-92 . . . . . . . . . . . . . . . . 1.2 Hrs. Adjust Hanger Brackets And Replace Pivot Bushings (with Automatic Air Suspension)
FAILURE CODE: 68 - Noisy