Odometer Speedometer gear. Porsche 911 76-89 / 911 (930) / 912E / 928 / 944  ❭  OG20X

Internal Odometer Speedometer Gear -  Multiple Tooth Count Options

Restore the operation of your classic Porsche speedometer with this OE Match Internal Odometer Speedometer Gear. Manufactured to replace the original internal plastic drive gear, this component restores the mechanical drive to the odometer and trip meter when the original gear has become worn, brittle or broken.

The internal odometer gear is housed within the speedometer and transfers drive from the speedometer mechanism to the odometer assembly. Over time, the original plastic gear naturally deteriorates through age and repeated use, often causing the odometer and trip meter to stop recording mileage while the speedometer needle continues to function normally.

Replacing the failed gear is a cost-effective repair that allows you to retain the original speedometer while restoring accurate mileage recording.

Choosing the Correct Gear

There are multiple tooth count options fitted to speedometers. Before ordering, the speedometer must be opened so the original gear can be inspected and the correct tooth count confirmed.

The replacement gear consists of:

• Outer gear: Always 20 teeth
  
• Inner gear: Available with 21 to 32 teeth, depending on your speedometer.

If the original gear is too damaged to count accurately, count the teeth on the mating gear instead. Use the following guide to determine the correct replacement:

Teeth on Mating Gear  - Required Gear
49 teeth                               20 x 21
48 teeth                               20 x 22
47 teeth                               20 x 23
41 teeth                               20 x 29
40 teeth                               20 x 30
38 teeth                               20 x 32

Please Note:
The speedometer must be dismantled to confirm both the correct gear style and tooth count before ordering. Ordering without verifying the existing gear may result in purchasing the incorrect replacement.

Key Features

• Restores odometer and trip meter operation
• Direct replacement for worn or broken internal plastic gears
• Multiple inner tooth count options available
• Outer gear always features 20 teeth
• Cost-effective alternative to replacing the complete speedometer
• Ideal for instrument restoration and repair

Fortunately, replacing the damaged gear restores normal operation while allowing you to retain your original factory instrument.

Common Symptoms of a Failed Odometer Gear

• Speedometer needle operates normally
• Odometer has stopped recording mileage
• Trip meter no longer advances
• Intermittent odometer operation
• Broken or cracked plastic gear inside the speedometer

Because Porsche used several different gear ratios throughout production, identifying the correct gear before ordering is essential for a successful repair.