Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Noise Conditions

Drive Link Noise: A whine or growl that increases or fades with engine RPM. This noise is most noticeable under a light throttle acceleration, or in Park or Neutral with the car stationary.

Final Drive Noise: A hum related to car speed. This noise is most noticeable under a light throttle acceleration or zero throttle coastdown.

Planetary Gear Noise: A whine related to car speed. This noise is most noticeable in First gear, Second gear, Fourth gear, or Reverse. The condition becomes less noticeable after an upshift.

Pump Noise: A high pitched whine that increases with engine RPM and may be affected by modulated line pressure boost.