Ring gear diameter can be a helpful way to identify which differential you have. The ring gear diameter is measured across the face of the gear. To obtain the ring gear diameter, simply place a tape measurer across the gear. This can be tricky if the ring gear & carrier are still in the housing.

How do I know what ring gear I have?

Ring gear diameter can be a helpful way to identify which differential you have. The ring gear diameter is measured across the face of the gear. To obtain the ring gear diameter, simply place a tape measurer across the gear. This can be tricky if the ring gear & carrier are still in the housing.

How do I know what gears my rear end has?

The large number is the ring-gear tooth count. To find the gear ratio, divide the big number by the little number. In the example to the left, 37 ÷ 12 = 3.083333. These are 3.08 gears.

What do the numbers on the ring gear mean?

First, the gear ratio is determined by the tooth combination. The number of teeth on the ring gear divided by the number of teeth on the pinion (eg: 41/11 = 3.73) equals the gear ratio. … This means that the pinion shaft is roughly 1/3 the diameter of the ring gear for a 3.00 to 1 gear set.

How do I know my ring size and pinion?

Use calipers to measure both ring and pinion diameters to a tenth of an inch. Count the teeth on both the ring gear and pinion. To determine the ratio between the gears, divide the number of teeth on the pinion by the number of teeth on the ring.

What is ring and pinion gear ratio?

The ratio is the number of teeth on the driven gear (ring) divided by the number of teeth on the drive gear (pinion). So, if the ring gear has 37 teeth and the pinion has 9 teeth, the ratio is 4.11:1. That also means that for every one turn of the ring gear, the pinion will turn 4.11 times.

Will VIN number tell me gear ratio?

The Gear Ratio Could Be In Your VIN Code Or Identification Plate. … Every number and letter within a VIN reveals information about the automobile, such as the make, model, year built and the engine size.

How do I tell what gear ratio my Chevy rear end has?

Identify your GMC or Chevrolet rear end gear ratio by the RPO Codes, usually located on the placard labeled “Service Parts Identification” inside the drivers door panel or glove box.

How can I tell what gear ratio I have without pulling cover?

So an easy way to determine your actual gear ratio is to check the tag attached to the differential cover by the cover bolts. On the tag there should be some numbering such as 3.54 or 3.73, either of those numbers will give you the stock axle ratio.

What is the difference between 3.73 and 4.10 gear ratio?

4.10s are going to accelerate faster and decelerate faster on lift. However the trade off is greater fuel consumption per mile driven and higher engine speed per given road speed. In basic terms the 4.10s will feel quicker and 3.73 will feel faster.

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How do I know what axle ratio I have?

Method 1: Count the number of teeth on the ring gear and the pinion. Divide the number of the ring gear’s teeth by the number of the pinion’s teeth. This will give you the axle ratio.

What transmission do I have by VIN number?

Another way is to crawl under the vehicle and look for part numbers. Using a good flashlight, look for part numbers stamped into the transmission pan or the transmission itself. Your local auto part store or dealer will be able to cross-reference the numbers to determine the kind of transmission the part belongs to.

How can you tell if a 14 bolt is a full floater?

You can spot a full-float rear axle by looking at the wheels; Full float axles have a tell-tale “axle end” that sticks out from the wheel surface. This is because the wheel hub on a full-float 14 bolt axle will stick out beyond the wheel mounting surface anywhere from (roughly) 2 to 4 inches.

What year is a 14 bolt?

First appearing in 1973, the 14-bolt is one of the most used rear axles in the General Motors stable. Found under ¾- and 1-ton GM trucks, vans and SUVs, the 14-bolt received a max torque rating of 6,242 pounds. Up until 1994, GM manufactured the 14-bolt in-house.

How can you tell a 12 bolt rear end?

Although not technically how it got its descriptive name, the easiest way to identify a 12-bolt rearend is obviously by the 12 bolts holding the rear cover in place. In actuality, the term 12-bolt is due to the 12 bolts holding the ring gear to the differential.

What rear end do I have by Vin?

Identify the VDS section, the fourth through eighth digits of the VIN. This section typically includes information such as the vehicle model, engine size and body type. While not every vehicle manufacturer includes gearbox ratio information in the VDS, this will be where the information is found if it was included.

How do I know if my truck has been Regeared?

Jack it up so 1 tire is off the ground. Put the transmission in neutral. Have someone turn the tire exactly 2 turns while you count the driveshaft revolutions. If you count 3 3/4 revolutions, the truck hasn’t been regeared.

How do I identify my GM rear axle?

The rear cover’s shape and the number of bolts are identifying features for GM rear differentials. The round 10-bolt cover with a bulge for the ring gear identifies this axle assembly as an 8.5-inch 10-bolt. The two lugs on the lower case at the 5 and 7 o’clock positions are also identifying features.

How do I identify my GM rear differential?

Information about Differentials in GM vehicles can usually be obtained by looking at the RPO or “Regular Production Option” codes contained in the Service Parts Identification tag in the glovebox. Whenever possible, reference the tag numbers when ordering parts for your Differential.

How do I know what Chevy differential I have?

Without an ID tag, differentials are identified by the number of cover bolts, the distinctive shape of the cover, the number of ring gear bolts, and ring gear diameter. They can also be identified by whether the center section is an integral or dropout design.

What are 3.55 gears good for?

With a 3.55 being a higher numerical number, Garrison says it will put more torque to the tire, allowing for faster acceleration and better performance on hill climbs.

What is the difference between 3.55 and 3.73 gears?

PERFORMANCE: The larger the axle ratio number, the quicker the truck will accelerate. For example, a truck equipped with 3.55:1 axle gearing will accelerate faster than one equipped with a 3.31 axle ratio. Similarly, a pickup with a 3.73 axle ratio will be faster than one with 3.55s.

What does 3.55 axle ratio mean?

The numbers 3.55 and 3.73 refer to Ford truck axle ratios. The axle ratio tells you the number of revolutions the drive shaft makes compared to the rear axle. For a 3.55 axle ratio, the drive shaft will turn 3.55 times for every one revolution of the tire.

How do you find the rpm of a gear ratio?

The general rule is – large to small gear means ‘multiply’ the velocity ratio by the rpm of the first gear. Divide 60 teeth by 30 teeth to find the velocity ratio. Multiply this number (2) by the rpm (120). This gives an answer of 240rpm.

How do you find the gear ratio?

To calculate the gear ratio: Divide the number of driven gear teeth by the number of drive gear teeth. In our example, it’s 28/21 or 4 : 3. This gear ratio shows that the smaller driver gear must turn 1,3 times to get the larger driven gear to make one complete turn.