Quick Answer: What Gear Ratio Do I Have By Vin?

What’s the best gear ratio for highway driving?

Rear end gears (2.79’s, 3.00’s, 3.25’s, etc) are great for freeway driving, bit not good for 0-60 MPH or accelerating from a dead stop.

Shorter gears (higher numbers) are much better suited for accelerating, such as 3.55, 3.73, 3.91’s, 4.11’s etc.

Always remember, for very “give” there is a “take”..

How do I find out what gear ratio my Ford truck has?

How to Find Out the Axle Ratio on a Ford PickupOpen the front door on the driver’s side.Locate the Truck Safety Compliance Certification Label on the door pillar near the door latch.Locate the two-digit code in the box labeled “AXLE,” which is just below the bar code.Match the code on the label to the corresponding rear axle ratio.

How do I know what size rear end I have?

Measure the diameter of the ring gear. This measurement equals the size of your rear end. Count how many bolts are on the inspection cover. If you have 10 bolts, then your Ford has a 7.5-inch or an 8.8-inch rear end.

How do I know what 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.

Where is the gear ratio stamped?

On the axle you might have a sticker, and on the differential cover you might have a little metal tag that’s sticking out. That will have the gear ratio stamped right on that.

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.

How do I find my axle ratio?

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.

Is 3.42 or 3.73 better?

The difference in towing mpg between the 3.42 and 3.73 gears at highway cruise speed, under the same conditions, should be less than 1 mpg because of the slightly higher rpm running 3.73s. Vehicle speed actually plays a bigger role in fuel economy than engine rpm.

How do you find the rpm of a gear?

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.

Is 3.55 or 3.73 gears better?

3.55 will give you a little better gas mileage on the highway and slightly more highway oriented performance. 3.73 may be better for towing, lower end power (off the line acceleration), and may result in worse gas mileage on the highway.

How do I know what axles My truck has?

The two most common ways to identify your differential are establishing your Chevy truck axle identification through axle tags, or the shape of your differential cover.

Can you have different gear ratios front and rear?

Yes you need the same ratio front and rear. If not, while in 4X4 something will break. It can be close though. 3.50 on one end and 3.55 on the other or 4.10 and 4.11 are acceptable.

How do I know what rear end I have?

Casting codes can also be used to identify the manufacture date.Count the number of inspection cover bolts on the rear end housing. … Identify the most common GM rear-end types. … Look at the shape of the inspection cover and the gasket. … Locate the GM manufactured rear-end casting date on the housing.

How do I identify my GM 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 gear ratio I have?

Turn the wheel TWO revolutions and count the number of driveshaft turns. The number of driveshaft rotations will help you determine your rear axle ratio. For example, if it turned 3 and a half times, it’s a 3.50:1 ratio. If it turned 4 and a quarter times, it’s a 4.25:1 ratio.

How do I find out what gear ratio my f150 has?

Locate the axle identification tag on the rear axle on the differential cover bolt in the 12 o’clock position. The number in the lower left-hand corner is the gear ratio, for example, “3.08.” If the number has an “L” in it, for example, “3L08,” it is a limited-slip axle.

Is it better to have a higher or lower gear ratio?

The higher the number the better the car will accelerate, but at the expense of high speed cruising. Now for the confusing part of the story. A high numerical gear ratio is called a low gear or low rear end, and vice versa. Low gears give fast acceleration, high gears give better cruising.