To do another, click the clear values button and then enter a new set of values. Autorestomod manic mechanic gasoline media 82,047 views 23. Dec 19, 2018 there is an old school way we used on reardrive vehicles that will get you in the ballpark. But that gear ratio would most commonly be referred to as 3. How to find the gear ratio on a gm rear end it still runs. Works for assembled axles in the junkyard or bare gears. Crawlpedias gear ratio calculator will find the ratio of your ring and pinion. My question to you is, have you ever changed the gear ratio in the rear end to make in more usable at highway speeds. Paint the ring gear teeth with a marking compound on both the drive. If the vehicle does not have a positraction unit, jack one drive wheel of off the ground. After you count the teeth on the gears in the rear. Anthony 2003 exemplifies this with a threewheel planetary. The value will be returned in estimated differential gear ratio, based on the entered values. This gear ratio and tire diameter chart is meant to give you an approximation of ideal rpms at highway speed 65 mph for three situations.
A quick overview of the mechanical advantage of gear ratios. Four ways to determine the ring and pinion gear ratio your axle has. Even then, the manual equipped cars are leaving a lot of potential on the table with their high factory differential gear. Divide the ring gear teeth number by the number of teeth on the. I would like to verify the gear ratio before i complete my rear end swap. Ring and pinion ratio calculator by number of teeth. Technical banjo rearend gear ratio counting teeth the. In this case, 275 is the tire tread width in millimeters, 75 refers to aspect percentage of tread width to yield the sidewall height, and 16 is the diameter of the tire. You will notice that while many of them are identical, a few have a different number of teeth on each gear that results in a minor shift up or down in the final gear ratio.
My dakota has no tags or stickers that say what the ratio is. Now youll always know with the easy to use slide rule calculator. What is the best way to find out what the gear ratio is. Im trying to understand rear end gear ratios and ring gears. Originally 98 allure 30255, now 2004 intrigue 11731. A while back, someone posted the easy way to determine the ratio of the rear end gears by turning the drums and counting the number of revolutions of the pinion shaft. I need information about teeth count on ring and pinion on banjo rear end gear sets. Is there an easy way to determine the gear ratio by counting the teeth on the ring gear. Jack up the rear end of the truck so that both rear tires are off the. If you do not know this ratio, you can simply put in 1. Youre going to have to put the car in nuetral or out of gear, so safety first. For example, a ring gear with 39 teeth and a pinion gear with 11 teeth.
The gear ratio calculator will determine the ratio of a gear set, based on the number of teeth on the ring gear and teeth on the pinion gear. For example, if we divide a ring gear with 41 teeth by a pinion gear with 10 teeth we find that the gear ratio is 4. Nov 08, 2007 gear ratio, or in a car, final drive ratio is basically the number of times the tires rotate in relation to the number of times the drive shaft or axles rotate. The rear axle gear ratio is the number of turns that the input of the differential at the driveshaft makes in relation to its output at the rear wheels. Jun 26, 2015 the rearend gear ratio refers to the relationship between the driven gear ring and the drive gear pinion, and is easily calculated by dividing the ring gear tooth count by the drive gear tooth count. In the case of a gear train with two gears, we need to do the following steps. As our trucks get older you never know whats been swapped in and out of them. Apr 23, 2003 for example, if we divide a ring gear with 41 teeth by a pinion gear with 10 teeth we find that the gear ratio is 4. How to choose the right gear ratio for your muscle car or. For example, if the ring gear has 41 teeth and the drive gear has 10 teeth, the correct gear ratio would be 4. What is the rear end gear ratio and how does it affect. This tells us that we have a 41 tooth ring gear and an 11 tooth pinion gear. Count the teeth on the ring gear and the pinion gear, then divide the ring gear tooth number by the pinion tooth number to find the ratio.
Tire diameter, transmission choice with or without overdrive and desired highway cruising speed. The advantage to pulling the cover is that you can inspect the diff and check what carrier type you have. You may also calculate rear axle gear ratio by dividing pinion gear tooth count by ring gear tooth count. This utility calculates the rear end gear or front end in the case of a front.
The following table contains a list of common axles along with their ring and pinion tooth count and ratios. How to choose the right axle ratio for your pickup. Listed are the expected rpms at 60 mph with a given rear end ratio and tire height. Understanding the concept of the gear ratio understanding a. Divide the ring teeth number by the pinion teeth number. Lets say in a rear wheel drive car you have a rear end gear of 3. Basic id ford 9 inch, rear, 8 inch rear end,carrier, center section, traction lok, episode 283 autor duration. Ring and pinion ratio calculator by number of teeth crawlpedia. Coupled with the factory rear end gear ranging from 2. If changing the gear ratio is desired, it is important to know exactly which rear housing is present.
How to calculate the rear axle gear ratio it still runs. Mar 30, 2009 thats the rear end gear ratio in the drive axle. Tire specifications have a three number format 27575r16. In our calculator, we are dividing the number of teeth on the pinion gear by the number of teeth on the ring gear. Also, the same car with the 401 v8 already had the 3. Standard rear differential gear ratio question the amc. Or you can count the number of turns of the pinion it takes to get one full turn of the. By dividing 41 by 11 4111 we come up with a ratio of 3. You can figure out the gear ratio of your ring and pinion in a few ways. If you have the rearend opened up where you can see the gears, count the teeth on the ring and pinion.
The chart below may be of some help in deciding what rear end ratio is right for you. This step is pretty simple, just count the teeth on your two gears and identify which gear will be your input and which will be your output. You have to find out what gear ratio you have in the front. The older they get the less you can can trust the option code sticker. If your vehicle is a 4x4, you will need to change the gears in both front and rear axles. Figure 4 is an emission per mile versus 010 second acceleration distance performance graph. Ever wonder what happens to your gear ratio when you put on a larger or smaller right rear or how many rpms you gain or lose by changing a set. You can also now calculate when using different transmission gear ratios, like in first gear or in overdrive. Jun 11, 2011 count the teeth on the pinion gear, and divide them into the teeth on the ring gear. Standard rear ends as delivered from the factory 19691989. Different gear ratios can have different effects in the way a vehicle performs.
They make it possible to determine exact gear ratios you just count the number of teeth in the two gears and divide. If you have the rearend opened up where you can see the gears, count the teeth on. The key to understanding gear ratios is to remember that, as the numerical ratio goes up, towing. Dec 27, 2008 i have a 1980 chevy k10 with a broke ring gear when i count the teeth i got 43 on ring gear and 14 teeth on the pinion gear this comes out to be a 3. The best way is to count the teeth on the ring gear and divide by the number of teeth on the pinion gear. Apr 24, 2017 basic id ford 9 inch, rear, 8 inch rear end,carrier, center section, traction lok, episode 283 autor duration.
Feb 24, 2008 my rear end went out in my 88 chevy 4x4 half ton, and i am tring to buy a new rear end online. But as i weigh over 40,000 lbs down the road, i need the higher gear ratio. Pdf relations between size and gear ratio in spur and planetary. The gear ratio when counting the ring and pinion teeth.
This is where an overdrive transmission is very advantageous. There are also several ways to determine the ratio manually even if you cant see the number of teeth on the ring gear or pinion. They prevent slippage between the gears therefore axles connected by gears are always synchronized exactly with one another. Choosing new rearend gears is as easy as 1, 2, 3, 4 street. While the gramsmile emissions figures are affected by a rear gear change, idle and no load tests, of course, are not. Use some chalk to mark the tire with an arrow at 6 oclock. If there is a removable cover on the differential, removing it and counting the teeth on the gears is the most reliable method. Axle ratio or rear end gear ratio is calculated by dividing the number of teeth on the ring. Enter the tire size diameter and the target vehicle speed in mph. This is probably the easiest way to measure your rearend ratio, as it doesnt require removing the differential cover. So if one gear has 60 teeth and another has 20, the gear ratio when. I see the bedwetters dont like a correct answer also.
They come in different sizes, and the ring and pinion necessary to change the ratio are specific to these sizes. My rear end went out in my 88 chevy 4x4 half ton, and i am tring to buy a new rear end online. You should be able to find your gear ratio listed on the axle tag, however, if that has gone missing, you can simply count the number of teeth on each gear and divide the number of ring gear teeth by the number of pinion gear teeth. The final drive isnt directly related to engine rotation as dictated by tire size. Lift the rear end of the vehicle off of the ground. If you have ever wondered what the gear ratio is in your rear wheel drive vehicle and. A moderate change in rear gear ratio will have a small effect, but a large change will have a larger effect on emissions per mile. Differential gear ratio calculator houston rebuilt axles and. Tire diameter will also have an effect on a vehicles final. One thing to keep in mind is that the carrier will be different with a 2. There are a couple of ways to find the gear ratio on a gm rear end. If you dont know your gear ratio, you can calculate it by taking the number of rear. Power is transmitted from the transmission to rear end 1. Understanding rear gear ratios dearborn pit stop blog.
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