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How to Tell If You Have a Posi Rear End

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If you have a muscle car from the 1960s or 1970s, chances are it came with a Posi rear end. But what is a Posi rear end? And how can you tell if your car has one?

A Posi rear end is a type of limited slip differential that allows both wheels to receive power from the engine at the same time. This helps improve traction, especially when accelerating from a stop or when driving on slippery surfaces. There are several ways to tell if your car has a Posi rear end.

How to know if you have POSI / Locker / Rear Diff

  • Open the hood of your vehicle and locate the differential
  • The differential is a large, metal housing located near the middle or rear of the vehicle
  • Inspect the differential for any leaks
  • If you see fluid leaking from the differential, it is likely that you have a posi rear end
  • Check for any unusual sounds coming from the differential
  • A posi rear end will often make a humming noise when turning corners or accelerating/decelerating quickly
  • Take your vehicle for a test drive and pay attention to how it handles turns and corners
  • A posi rear end will often provide better traction and stability when taking turns at high speeds or on slippery surfaces

What is a Posi Rear End

A Posi Rear End is a type of differential that provides for more traction by evenly distributing the power to both wheels. This is done by using a clutch system to engage both sides of the differential at the same time, rather than just one side as in most standard differentials. This allows both wheels to receive an equal amount of torque, providing better traction and stability when cornering or driving on slippery surfaces.

Posi Rear End Vs Limited Slip

There are many performance benefits to be had by upgrading the rear end in your muscle car. One of the most popular upgrades is to swap out the factory Posi (limited slip) unit for a more performance-oriented aftermarket limited slip differential. But what exactly is a limited slip differential and how does it differ from a Posi unit?

A limited slip differential uses a variety of methods to prevent both wheels from spinning independently of each other. This allows for greater traction when accelerating, as both wheels are receiving power simultaneously. A Posi unit uses clutch plates or cones to achieve this locking effect, while an aftermarket LSD will use gears, ramps, and clutches.

The main advantage of an aftermarket LSD over a Posi unit is that they can be tuned to provide different levels of lockup. This means that you can have a streetable car with great traction off the line, but still have the ability to slide around corners if you so desire. Many people find that an aftermarket LSD provides better overall traction than a stock Posi unit due to its tunability.

How to Tell If You Have a Locker Rear End

If you think you may have a locker rear end, there are a few things you can look for to be sure. First, check the axle ratio. If it’s 3.73 or lower, it’s likely that you have a locker rear end.

Next, check the carrier casting number. If it’s 1310 or 1330, you probably have a locker rear end. Finally, take a look at the axles themselves.

If they’re 30 spline or larger, chances are good that you have a locker rear end.

Posi Rear End 10-Bolt

A posi rear end 10-bolt is a high performance differential that provides increased traction for your vehicle. This type of differential uses clutch plates to lock the two axles together, allowing both wheels to rotate at the same speed. This is ideal for drag racing or any other situation where you need maximum traction.

The Posi Rear End 10-bolt was first introduced in 1964, and it quickly became popular among racers and enthusiasts alike. It wasn’t long before aftermarket companies began offering Posi units for sale. Today, there are many different brands and models of Posi Rear Ends on the market, each with its own set of features and benefits.

If you’re looking for improved traction and performance from your vehicle, a Posi Rear End 10-bolt may be just what you need.

Posi Rear End Conversion Kit

Are you looking for a Posi Rear End Conversion Kit? If so, you’ve come to the right place! Here at JEGS, we offer a variety of Posi Rear End Conversion Kits to fit your needs.

A Posi Rear End is a great way to improve the traction of your car or truck. With a Posi Rear End, both rear wheels will receive power instead of just one. This means that your car or truck will be able to better handle slippery conditions and will have increased acceleration.

There are many different types of Posi Rear Ends available on the market today. Some kits are designed for street use while others are meant for race applications. No matter what type of driving you do, there’s a kit out there that’s perfect for you.

If you’re not sure which kit is right for your car or truck, our team of experts is here to help! Give us a call or send us an email and we’ll be happy to assist you in finding the perfect Posi Rear End Conversion Kit for your vehicle.

Posi Trac

Posi Trac is a type of differential used in many four-wheel drive vehicles. It uses clutch packs to provide extra traction when one wheel starts to slip. This can be extremely helpful when driving in slippery conditions, such as mud or snow.

Posi Trac can also improve your vehicle’s performance when cornering by evenly distributing power to all four wheels.

Posi Car Meaning

A posi car is a vehicle that uses positive traction to move forward. This type of car typically has two wheels that are driven by the engine and two wheels that are not. The advantage of a posi car is that it can provide better traction on slippery or icy roads.

Posi Differential

A positraction differential, commonly called a posi-diff, is a type of limited slip differential that uses clutches or cone/spring packs to distribute torque evenly between the two wheels. This allows both wheels to rotate at the same speed, even if one wheel has more traction than the other. Posi-diffs are used in high performance applications where traction is important, such as drag racing and road racing.

Some off-road vehicles also use posi-diffs to keep both wheels turning when one is on a loose surface like sand or gravel.

How to Tell If You Have a Posi Rear End


How Do I Know If My Differential is Posi?

Differential gears are used in cars and trucks to help the wheels turn at different speeds. When one wheel is turning faster than the other, the differential helps to distribute power evenly so that both wheels can maintain traction. Differentials can be either “open” or “posi” (positive traction).

Open differentials are the most common type of differential and they work well under most driving conditions. However, if you frequently drive in slippery conditions (snow, ice, mud), then you may want to consider a posi-traction differential. A posi-traction differential uses clutch plates to join the two halves of the axle together.

This prevents one wheel from spinning uncontrollably when there is little traction. Posi-traction differentials are more expensive than open differentials, but they can be worth the investment if you do a lot of off-road driving or live in an area with frequent inclement weather. To determine if your car has an open or posi-traction differential, look for a sticker on the differential cover.

If it says “posi” or “limited slip,” then you have a posi-traction differential. If there is no sticker, then you likely have an open differential.

How Do You Know If Its Positraction?

Positraction is a term used to describe a situation where two objects are moving in the same direction but at different speeds. The object that is positracting is usually the one that is moving faster. There are several ways to tell if something is positracting.

One way is to look at the objects involved. If they are both moving in the same direction, then it’s likely that one of them is positracting. Another way to tell is by looking at the tracks left behind by the objects.

If the tracks diverge, then it’s likely that positraction was taking place. Finally, you can also listen for a faint humming noise coming from the object that’s positracting. This noise is caused by friction between the two objects and is known as the Positraction Effect.

How Do I Know If My 12 Bolt Rear is Posi?

Assuming you have a 12 bolt GM rear end, there are a few ways to tell if it is positraction or not. One way is to look for the word “Positraction” on the differential cover. Another way is to check the gear ratio.

Positraction rear ends usually have a 3.42:1 or lower gear ratio. Finally, you can remove the differential cover and look for two spider gears (positraction has two spider gears whereas non-positraction only has one).

Is Limited Slip And Posi the Same?

If you’re a car enthusiast, chances are you’ve come across the terms “limited slip” and “posi” while perusing forums or chatting with friends. But what do these terms actually mean? Are they interchangeable?

In short, no. While both limited slip and posi (short for positive traction) differentials provide increased traction compared to standard open diffs, they work in different ways. Limited slip diffs use clutch plates or cones to prevent one wheel from spinning faster than the other.

This type of differential is often used in performance applications where increased traction is desired but not necessarily required, such as on a dry race track. Positive traction diffs, on the other hand, use gear teeth to lock the two wheels together so that they rotate at the same speed. This is ideal for off-road or slippery conditions where maximum traction is necessary.

So, there you have it! The next time someone asks if limited slip and posi are the same thing, you can set them straight.


If you’re not sure whether or not your car has a Posi rear end, there are a few things you can look for to help you determine. First, check to see if your car has limited-slip differential. This is typically indicated by a sticker on the inside of the glove box door or in the owner’s manual.

If your car does have limited-slip differential, it’s likely that it also has a Posi rear end. Another way to tell if your car has a Posi rear end is by looking at the tires. If all four tires are the same size and brand, then it’s very likely that your car has a Posi rear end.

This is because cars with Posi rear ends tend to wear out tires evenly, so all four tires will be the same size when they need to be replaced. Finally, you can try putting your car in neutral and spinning the wheels. If both wheels spin at the same speed, then it’s likely that you have a Posi rear end.

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