Symptom Chart - NVH
NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, REFER to: Noise, Vibration and Harshness (NVH) . Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, REFER to: Noise, Vibration and Harshness (NVH) . For the next likely system and continue diagnosis.
Additional diagnostics may be necessary to further isolate the concern. An electronic listening tool such as Chassis Ear ® may be used. Follow the tool manufacturer's instructions and the Possible Sources found in the following NVH chart to determine the connection points.
| Symptom | Possible Sources | Action |
|---|---|---|
| Clunk - noise from the front suspension, occurs in and out of turns | Loose front shocks | INSPECT for shock absorber fasteners. TIGHTEN to specifications. REFER to: Front Shock Absorber - F-250/F-350 . or REFER to: Front Shock Absorber - F-450/F-550 . or REFER to: Front Shock Absorber 4WD . |
| Clunk - noise from the rear suspension, occurs when shifting from REVERSE to DRIVE | Loose or damaged rear suspension components | INSPECT for loose or damaged rear suspension components. REPAIR or INSTALL new components as necessary. REFER to the appropriate Suspension article for the procedure. |
| Click or pop - noise from the front suspension. More noticeable over rough roads or over bumps | Worn or damaged kingpin(s) or bushing(s) | INSPECT front kingpin bushing(s). . |
| Front suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or rough road | Loose or bent front shock absorber(s) Damaged spring or spring mount(s) |
INSPECT the front suspension. INSTALL new components as necessary. REFER to the appropriate Suspension article for the procedure. |
| Rear suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or rough roads | Loose or bent rear shock absorber(s) Damaged spring or spring mount(s) Damaged or worn bushing(s) |
INSPECT rear suspension. INSTALL new components as necessary. REFER to the appropriate Suspension article for the procedure. |
| Shudder - occurs during acceleration from a slow speed or stop | Incorrect ride height causing incorrect driveline angle | REFER to: Driveshaft . |
| Shimmy | Loose wheel nut(s) | TIGHTEN nut(s) to specification. REFER to: Wheel and Tire - Vehicles With: Single Rear Wheels . or REFER to: Wheel and Tire - Vehicles With: Dual Rear Wheels . |
| Loose front suspension fastener(s) | TIGHTEN fastener(s) to specification. REFER to the appropriate Suspension article for the procedure. | |
| Loose front wheel bearing(s) | INSPECT front wheel bearing(s). REFER to Wheel Bearing Inspection . INSTALL new bearing(s) as necessary. | |
| Shock absorber(s) | INSPECT shock absorbers. INSTALL new shock absorber(s) as necessary. REFER to: Front Shock Absorber - F-250/F-350 RWD . or REFER to: Front Shock Absorber - F-450/F-550 RWD . or REFER to: Front Shock Absorber 4WD . or REFER to: Rear Shock Absorber . | |
| Shimmy - most noticeable on coast/deceleration. Also hard steering condition | Excessive positive caster | CHECK front caster and ADJUST as necessary. REFER to: Front Camber and Caster Adjustment - F-250/F-350, RWD . or REFER to: Front Camber and Caster Adjustment - F-250/F-350/F-450/F-550, 4WD . |
| Rough/harsh ride | Shock absorber(s) | INSPECT shock absorbers. INSTALL new shock absorber(s) as necessary. REFER to: Front Shock Absorber - F-250/F-350 RWD . or REFER to: Front Shock Absorber - F-450/F-550 RWD . or REFER to: Front Shock Absorber 4WD . or REFER to: Rear Shock Absorber . |
| Spring(s) | INSTALL new spring(s) as necessary. REFER to: Front Spring - F-250/F-350 RWD . or REFER to: Front Spring - F-450/F-550 RWD . or REFER to: Front Spring 4WD . or REFER to: Rear Spring - F-250/F-350 . or REFER to: Rear Spring - F-450/F-550 . | |