1. What is the TH350 Speedometer Gear Calculation?

The TH350 speedometer gear calculation determines the proper number of teeth needed on the driven gear to ensure accurate speedometer readings after changes to axle ratio or tire size.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• Drive Teeth — Number of teeth on the transmission's drive gear
• Axle Ratio — Rear axle gear ratio
• Tire Revolutions per Mile — How many times your tire rotates in one mile

Explanation: The equation accounts for the relationship between transmission output, axle ratio, and tire size to determine the correct speedometer gear.

3. Importance of Correct Speedometer Gear

Details: An incorrect speedometer gear will cause inaccurate speed readings and may affect odometer accuracy. This is particularly important after changing tire sizes or axle ratios.

4. Using the Calculator

Tips: Enter the number of teeth on your drive gear, your axle ratio, and tire revolutions per mile. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Where can I find my drive gear tooth count?
A: The drive gear is inside the transmission and typically has 6-8 teeth. Consult your service manual or transmission documentation.

Q2: How do I determine tire revolutions per mile?
A: This can be calculated from tire size or found in tire manufacturer specifications. Many online calculators can help with this.

Q3: What if my calculated gear teeth isn't a whole number?
A: Speedometer gears only come in whole tooth counts. Round to the nearest available gear and accept slight speedometer error, or consider changing drive gear.

Q4: Are there standard gear tooth counts available?
A: Yes, common driven gear tooth counts range from 18 to 45 teeth in most applications.

Q5: Can this calculator be used for other transmissions?
A: While the principle is similar, other transmissions may use different calculation methods or gear types.