F: Speedometer/Odometer Reads Erroneously, Ranger and Explorer
F1 CHECK CONNECTIONS
^ Verify quick connect is properly attached at speedometer.
^ Are all connections good?
Yes
GO to F2.
No
REPAIR or REPLACE as necessary. CHECK for accuracy.
F2 CHECK ODOMETER
^ Check accuracy of odometer.
^ If odometer is accurate calibration of speedometer may be off. Changing the speedometer may correct but going on to change either gear will make speedometer reading more accurate but now odometer will not be accurate.
^ Is odometer accurate?
Yes
REPLACE speedometer. CHECK for speedometer accuracy.
No
GO to F3.
F3 CHECK DRIVEN GEAR
^ Check for proper driven gear. Refer to the Ford Speedometer Gear Supplement Charts for speedometer gear applications.
^ If odometer is accurate calibration of speedometer may be off. Changing the speedometer may correct but going on to change either gear will make speedometer reading more accurate but now odometer will not be accurate.
^ Is the correct driven gear installed?
Yes
GO to F4.
No
REPLACE gear with correct gear. CHECK for accuracy.
F4 CHECK DRIVE GEAR AXLE, TIRES AND RATIO ADAPTOR
^ Check for proper drive gear axle tires and ratio adaptor.
^ Is drive gear axle, tire and ratio adapter correct?
Yes
REPLACE speedometer. CHECK for accuracy.
No
REPLACE incorrect component or driven gear. CHECK for accuracy.