LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2008 >> Expedition EL RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Four Wheel Drive (4WD) Systems) >> Diagnostic Tests >> Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand >> Symptom Chart - NVH

Symptom Chart - NVH

WARNING: This page is about a different variant/trim than selected.
NOTE: 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 article. 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 back to NOISE, VIBRATION AND HARSHNESS article for the next likely system and continue diagnosis.
Symptom Chart - NVH

Condition Possible Sources Action
  • Transfer case whine - noise at all ranges
  • Incorrect fluid level or fluid quality
  • Worn oil pump
  • Under-inflated or oversized tires
  • CHECK that the transfer case is filled to the correct level and with the specified fluid. REFER to TRANSFER CASE article.
  • DISASSEMBLE the transfer case. CHECK the oil pump for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE article.
  • CONFIRM that the tires and wheels are correct for the vehicle. CHECK that the tire inflation pressures are correct.
  • Transfer case growl/rumble - noise at all ranges
  • Damaged or worn bearings or planetary gear
  • DISASSEMBLE the transfer case. CHECK the bearings or planetary gear for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE article.
  • Transfer case scraping/grating - noise at all ranges
  • Excessively stretched drive chain hitting the case
  • DISASSEMBLE the transfer case. CHECK the drive chain for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE article.
  • Transfer case howl/hum - noise at all ranges or 4X4 only
  • Worn or damaged sun (input) gear, clutch pack (intermediate) gear or output shaft gear
  • DISASSEMBLE the transfer case. CHECK the gears for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE article.