## How do you calculate the gear ratio on a speedometer?

How to calculate the number of teeth on speedometer drive gear?

1. Divide the number 20168 by the diameter of the tire to find the number of revolutions per mile.
2. Multiply the revolutions with axle ratio, A .
3. Divide the product with 1001 .
4. Multiply the gear ratio with the number of teeth on the driven gear, N .

## How do I know what size speedometer gear 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.

How do I identify a Dana 20?

The Dana 20 is a cast iron transfer case, having a passenger-side front output and a centered rear output. It has the same “Texas” front mounting input flange as does the Dana 18. Markings on the Dana 20 can vary, but most start with a C18-15-24… Some confuse them for a large case Dana 18 because of this.

Is a Dana 20 transfer case any good?

The stock Dana 20 transfer case found in a lot of Jeeps, Scouts, and Broncos is a sturdy and reliable unit. However, its Low-range gear ratio is only 2.03:1.

### Who can calibrate a speedometer?

auto-mechanics
Most auto-mechanics perform speedometer calibrations, and some driving schools perform them as well. The cost is usually approximately \$75.

### What is speedometer ratio?

Speedometer ratio is basically the ratio or the relationship between the speedometer input and the speedometer output while factoring in other things such as the size of the vehicle’s wheels and tires, the tail shaft gears that drive the flexible cable, and the final drive ratio in the differential.

What is a Dana 20?

The Dana 20 transfer case is a medium-duty, gear-drive unit that was manufactured from about 1962 to 1979. It is a part-time, manual-shift t-case that was found in Jeep, GM, Ford, and some International Harvester vehicles. The cast iron housing helps contribute to its reputation as a robust and reliable transfer case.

How much oil does a Dana 20 take?

High5 Member. I looked in my Haynes Manual and it states in there that the Dana 20 transfer case takes 3.25 pints of gear oil.

#### What is the difference between a Spicer Model 18 and 20?

It is of note that the 20 was based off of the design of the 18 and Spicer used this numbering scheme throughout the span of the production of the Models 18 and 20, which for a time were built concurrently. It should be mentioned that there was a variation of the Model 20 – the Model 21.

#### What kind of input shaft does a Muncie 4 speed have?

In the middle is the M21 countershaft and input shaft. On the far right is the M22 26-spline input shaft. In the 1970s, virtually all Muncie four-speeds had 26-spline input shafts. 8. The M22 Rock Crusher 26-spline input shaft sports a wider gear for greater torque capacity.

Are inter intermediate gear bores the same as 1-1/8?

Intermediate gear bores are identical for 1-1/8″ and 1-1/4″ applications. c. The Bronco gear used for Jeep Dana 20, 2.46:1 conversions

What is the difference between 26 spline and 10 spline gears?

The 10 spline vs. 26 spline shafts show no greater nor less tendency towards breakage, as the shaft diameters (the real measure of strength, not spline count) are very similar. The gearset in the Dana 20 is strong, but unbalanced.