How many teeth does a th350 speedometer have?
The Turbo 350, Powerglide, and GM four-speeds have driven gears that have anywhere from 17 to 25 teeth. Speedometer driven gears in the Turbo 400 and 700R4 have between 34 and 45 teeth.
Which speedo gear do I need?
To determine your tires true diameter in relation to determining what speedometer gears you need, measure from the ground up to the center of the axle then multiply by two. The actual run out of the tire can be as much as 2 to 3 inches less than what the circumference of the tire measures.
What is the gear ratio of a th350?
Gear ratios vary, but the Turbo 350 typically has a first gear ratio of 2.52 to 1.00; 1.52 to 1.00 for second; direct drive in third; and 2.07 to 1.00 in reverse.
Where is the speedometer drive gear typically located?
Older vehicles use mechanical speedometers. They have 2 gears that work together to measure vehicle speed. These “Speedo Gears” are usually located in the transmission. The Drive Gear is located on the output shaft.
How is speedometer drive gear calculated?
How to calculate the number of teeth on speedometer drive gear?
- Divide the number 20168 by the diameter of the tire to find the number of revolutions per mile.
- Multiply the revolutions with axle ratio, A .
- Divide the product with 1001 .
- Multiply the gear ratio with the number of teeth on the driven gear, N .
How does a Speedo drive work?
A flexible drive cable inside a flexible tube links a small magnet inside the speedometer to the gearbox output shaft. The magnet rotates with the shaft and its magnetic field attracts a metal drum to turn the speedometer needle against the force of a hair spring.
Is a TH350 a 4 speed?
TH350 Transmissions 101 The TH350 transmission is a three-speed automatic transmission launched by General Motors in vehicles from 1968. It can also be said this model was created as a collaboration between Chevrolet and Buick, where the transmission was made to be compact, strong, and versatile.