Suspension - Noises on Rough Roads

Classification:
FA91-002

Reference:
NTB91-085

Date:
October 18, 1991

FRONT SUSPENSION NOISE

APPLIED VEHICLE(S):
1989 - 1991 240SX (S13)

SERVICE INFORMATION

Some 1989 - 1991 240SX vehicles may exhibit a metallic noise from the front suspension when driven over rough roads (potholes, broken pavement, etc.) at low speeds (5-20 mph). The noise is most easily heard with the window down and is caused by the coils of the front spring contacting each other. This noise is not an indication of suspension malfunction. This bulletin contains Parts Information and Service Procedures to eliminate this noise.

The countermeasure consists of 4 pieces of urethane tubing. The tubing isolates the spring coils and prevents metal-to-metal contact.

These tubes should be attached to the spring with high strength contact adhesive.

NOTE:
Normal weatherstrip adhesive should not be used. It does not have adequate strength for long-term durability.

SERVICE PROCEDURE

1. Remove strut assembly fixing bolts and nuts (to hoodledge).
Do not remove piston rod lock nut on vehicle.





2. Set strut assembly on vise with Tool, then loosen piston rod lock nut.

WARNING:
Do not remove piston rod lock nut.





3. Compress spring with a Tool so that strut mounting insulator can be turned by hand.





4. Remove piston rod lock nut and then remove the spring.





5. Clean the coils with solvent where the tubes will be installed to remove grease, oil, and road dirt. Apply a thin coating of adhesive to the inside of the urethane tubes and to the coils on the spring in the areas shown. Position the upper and lower tubes so that the ends of the tubes are located 3/4 of a coil (2700) from the end of the coil as shown.

NOTE:
On some vehicles, already existing urethane tubes may be in place on certain coils of the spring. Do not remove these tubes, removal may result in spring noise. Check the adherence of the existing tubes to the coils and apply adhesive if necessary.

6. Let the tubes dry in place for 10-20 minutes. Remove any excess adhesive, then install the spring onto the strut. Install the spring with the paint code marks DOWN and the bottom coil matched to the lower spring seat.





7. When installing coil spring, be careful not to reverse top and bottom direction. (Top end is flat).





8. When installing coil spring on strut, it must be positioned as shown.





9. Install upper spring seat with its cutout facing the inner side of vehicle.





PARTS INFORMATION





CLAIMS INFORMATION