How do I tell what rear end is in my Chevy truck?
As a Chevy truck owner, understanding the type of rear end in your vehicle is crucial for maintenance, repairs, and upgrades. The rear end, or differential, plays a vital role in transferring power from the engine to the wheels, and knowing its specifications can help you make informed decisions about your truck. In this guide, we’ll walk you through the steps to identify the rear end in your Chevy truck.
Why Knowing Your Rear End Type Matters
The rear end type affects your truck's performance, towing capacity, and compatibility with aftermarket parts. Whether you're replacing parts, upgrading for better performance, or simply curious, identifying the rear end ensures you get the right components and avoid costly mistakes.
Steps to Identify the Rear End in Your Chevy Truck
Follow these steps to determine the type of rear end in your Chevy truck:
- Check the Service Parts Identification (SPID) Label: Locate the SPID label, typically found inside the glove box or on the driver-side door jamb. This label contains a list of RPO (Regular Production Option) codes that specify the components of your truck, including the rear end. Look for codes like "GU6" (3.42 ratio) or "GT4" (3.73 ratio).
- Inspect the Differential Cover: The shape and number of bolts on the differential cover can help identify the rear end. For example, a 10-bolt cover is common in Chevy trucks with a 10-bolt rear end.
- Count the Axle Splines: If you're comfortable disassembling the axle, count the number of splines on the axle shaft. This can provide additional confirmation of the rear end type.
- Measure the Ring Gear Diameter: Remove the differential cover and measure the diameter of the ring gear. Common sizes for Chevy trucks include 8.5 inches and 9.5 inches.
- Consult the Owner’s Manual: Your truck's owner’s manual may include information about the rear end specifications.
- Use Online Resources: Many websites and forums dedicated to Chevy trucks provide RPO code decoders and rear end identification guides.
Common Rear End Types in Chevy Trucks
Chevy trucks are equipped with various rear end types depending on the model and year. Here are some of the most common ones:
- 10-Bolt Rear End: Found in many light-duty Chevy trucks, this rear end is known for its reliability and versatility.
- 12-Bolt Rear End: A stronger option often used in performance or heavy-duty applications.
- 14-Bolt Rear End: Common in heavy-duty trucks, this rear end is designed for high towing and payload capacities.
When to Seek Professional Help
If you're unsure about identifying your rear end or need assistance with repairs, it’s always a good idea to consult a professional. At Kevin's Autos, we have years of experience in car maintenance and repair, and we’re here to help you with all your Chevy truck needs. Contact us today for expert advice and service!
Frequently Asked Questions
How do I figure out what rear end is in my truck?
It's in your vin, look up an online decoder and it will tell you. Your rear axle will also have a tag on it with a code for its gear ratio if you want to crawl under it for some reason.
How to identify a Chevy rear differential?
If the ID tag or stamp is missing or unreadable, differentials can be 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.
How do I know what size my differential is?
Once your differential is disassembled and its parts removed, it's time to measure your ring gear to determine its diameter. Simply measure from the widest point of the gear, tooth tip to tooth tip Pinion nut size is another parameter that can be used to identify the diff.
How do I tell what gear ratio my Chevy rear end has?
You may have a different code stamped on you axle tube as well. If you can find it under the rust, it can be used to find your gear ratio as well. The only other way to find your ratio would be turning the wheel/axle by hand and counting rotations, or opening up the axle and counting teeth.
What size is the rear axle on a Chevy Silverado?
9.76-inch rear axle.
What is considered the rear end of a truck?
The “rear end” is your mechanic's shorthand for the differential. The differential is essentially a complex box of gears that allows the wheels to turn at different speeds when you take turns. Without it, you'd be dragging your outside wheel along the pavement whenever you turn.
How do you tell the difference between a limited-slip differential and a regular diff?
The open diff results in the inside tire spinning while the outside tire has plenty of grip. In contrast, the LSD works by locking the diff as soon as the inside wheel starts to spin, distributing power to both tires and causing a controlled slide.
How do you tell if you have an 8.5 or 8.6 rear end?
The easiest way to tell the difference is by looking at the brakes. All 8.6-inch rears have disc brakes, and 8.5-inch units have drum brakes.
How can you tell the difference between a 3.73 and a 4.10 gear ratio?
Likewise, if the driveshaft spins roughly 3 ¾ times, that will equal a 3.73 rear end gear, and if it spins just over 4 times, this will equate to a 4.10 rear end gear.
Where do I find my GM axle code?
The GM RPO Codes label is usually located inside the glove box or on the Driver's Side Door Jamb (on the B-Pillar). The silver placard will be labeled “Service Parts Identification” and includes a bunch of three-digit codes. The prefix for GM RPO codes relevant to Axle Identification is almost always “G”.
