Frequently Asked Questions
Here are some commonly asked questions that may help you with your order
Q:	What is the BOM number?
A:	BOM (Bill of Materials) is a number used by DANA to specify the parts used to build rear ends. If you have DANA parts it will help us find the correct parts for your application if you find the BOM number.
	See Extras
Q:	How do I find the correct ratio to use for my application?
A:	Use the following formula: mph * gear ratio * trans ratio * 336 / Tire Diameter = RPM
Q:	How can I determine the ratio of my rear end?
A:	1. Look for any markings or stampings in your housing that write out the ratio 2. Count the teeth on your ring gear and pinion gear and divide the number of ring gear teeth by the number of pinion gear teeth 3. Try and find any numbers on either your ring gear and/or your pinion gear and we may be able to find your ratio.
Q:	What information is needed to make ordering easy for me and Nationwide Parts?
A:	1. Know the year, make and model of your vehicle 2. Have the number of axle spline 3. Have the number of spline on the pinion 4. Have the ring gear diameter 5. How many cover bolts 6. The physical appearance of the cover; what it looks like
Q:	Should I get a Pro Gear or a Street Gear?
A:	The difference between Pro Gear and Street Gear should help you determine which is right for your application. Street Gears are made for everyday driving. Heat and distance are not an issue for street gear sets. Because Street Gear sets can handle long distances and extreme heat, they are often used for oval track racing too. Pro Gears are used specifically for drag racing. Pro Gear set are designed to bend instead of break-off when excessive torque is used. Street Gears are more rigid and would break.
Q:	What is limited slip and posi?
A:	Limited slip and posi one in the same. Limited slip (or Posi) happens when the tires turn - on an even surface both tire turn equally yet on uneven surface one tire is allowed to turn at a different rate to allow for better traction.
Q:	What should my backlash be for my ring and pinion?
A:	For Street Use (light duty vehicles, 1 ton or less) backlash should be .007 to .010 For Pro Gears (drag racing vehicles) backlash should be .006 to .008
Q:	How do I measure a driveshaft?
A:	Take the slip yoke for the transimission or transfer case and push it all the way in, then pull it out to about 3/4'' to 1''. This is normal riding position. Measure the driveshaft from the center of the U-joint cap to the center of the U-joint cap at ride height