If you have a car with a Posi rear end, there are several ways to tell. One way is to check for fluid leaks. Another way is to jack up the car and try to spin one of the rear wheels.
If the wheel spins freely, then you likely have a Posi rear end. You can also drive the car and see how it behaves when cornering or under hard acceleration. If the car feels tight and doesn’t slip, then you probably have a Posi rear end.
- Open the hood of your vehicle and locate the differential
- With the vehicle in park and the emergency brake engaged, rotate one of the rear wheels by hand
- If you feel resistance when rotating the wheel, stop and check for a posi-traction sticker on the differential cover
- If there is no sticker, proceed to step 4
- Jack up one of the rear wheels off the ground and place a drain pan underneath it
- Unscrew and remove the fill plug on the side of the differential using a ratchet and socket
- If gear oil begins dripping out of the fill hole, then you have a posi-traction rear end; if not, then you do not have a posi-traction rear end
How to know if you have POSI / Locker / Rear Diff
Posi Rear End Vs Limited Slip
There are many factors to consider when choosing between a Posi Rear End and Limited Slip for your car. The most important factor is what you will be using the car for. If you plan on doing any off-road driving, then a Posi Rear End is the best choice.
This is because it provides better traction and can handle more abuse than a Limited Slip. However, if you only plan on driving your car on the street, then a Limited Slip may be the better option. It will provide better fuel economy and smoother operation.
Credit: nastyz28.com
How Do I Know If My Rear is Posi?
Assuming you have a factory equipped Posi-traction rear end, there are a few ways to tell if it’s working properly. One way is to jack up the car and place it on jack stands. With the car in neutral, spin one of the rear wheels.
If the other wheel spins in the same direction, then your Posi is working correctly. If the other wheel spins in the opposite direction or doesn’t spin at all, then your Posi needs to be serviced. Another way to check is to do a “brake test”.
With the car in neutral and both wheels off the ground, apply the brakes lightly and then let off. The Posi should engage and both wheels should stop spinning at the same time. If one wheel continues to spin while the other doesn’t, then your Posi isn’t working right.
If you don’t have a factory installed Posi-traction rear end, there are still some ways to tell if you have one or not. One clue is if your car has limited slip differential (LSD) listed as an option on the build sheet or window sticker. Many times, cars that come with LSD will also have Posi- traction as well.
Other clues that may indicate you have aPosi include hearing a chattering noise when turning sharply at low speeds or feeling like your car wants to “push” through turns rather than going straight ahead when accelerating hard out of corners..
How Do I Know If My Rear End is Posi Or Limited-Slip?
If your car is equipped with a posi or limited-slip differential, it will have the ability to distribute power to both wheels equally. This is beneficial because it prevents one wheel from spinning excessively and allows for better traction when driving on slippery surfaces. To determine if your car has a posi or limited-slip differential, there are a few things you can look for.
First, check your owner’s manual. It should list whether or not your car is equipped with this type of differential. If you don’t have the owner’s manual, you can also check the door sticker.
This should also indicate whether or not your car has a posi or limited-slip differential. Another way to tell is by looking at the rear axle itself. If there are two bolts holding each side of the axle together, then it’s likely that your car has a Posi rear end.
However, if there is only one bolt holding each side of the axle together, then it’s likely that your car has a limited-slip differential. Finally, you can also tell by the way your car behaves when driving on slippery surfaces. If both wheels seem to be receiving equal power and aren’t slipping excessively, then it’s likely that you have a posi or limited-slip differential in your vehicle.
Is Posi And Limited-Slip the Same Thing?
Most people believe that Posi and limited-slip are the same thing, when in fact they are two very different technologies. Limited-slip is a clutch-based system that uses friction plates to allow some wheels to slip while others remain engaged. This can be useful in certain situations, such as when one wheel is on a slippery surface while the other has traction.
Posi is a cone-type differential that uses special gears to distribute power evenly to both wheels, regardless of traction conditions. This makes it ideal for use in all conditions, including off-road driving.
What’S the Difference between Positraction And Limited-Slip?
Differential gears are used in all wheel drive and rear-wheel drive vehicles to split engine torque between the front and rear axles. In a conventional, or “open” differential, Equal torque is supplied to both wheels regardless of traction conditions.
This may be fine most of the time, but can cause problems when one wheel loses traction – as happens when you drive on ice, snow, or even a wet grassy lawn.
When one wheel slips, it spins faster than the other wheel and the open differential directs more power to the slipping wheel.
Since this spinning wheel has less traction than the other one, it just gets worse and worse until finally both wheels are slipping.
Positraction is an early form of limited slip differential that uses clutch plates to couple together side gears mounted on spider gears.
When one wheel begins to slip, posi limits slippage by transferring power from the slipping wheel to the opposite wheel through a series of clutches.
Positraction was introduced in 1957 by General Motors for their Chevrolet division under exclusive license from American Bantam Car Company who developed it.
The name “Positraction” is a registered trademark of GM’s Chevy division[1] although GM no longer uses that name.
Instead they use “limited slip” or “locker” depending on how much control they want over how much power is sent where.
Limited Slip Differentials (LSD) use various mechanisms to limit slippage between driven wheels while still allowing some degree of independent rotation (unlike locking differentials).
LSDs are designed so that when one driven wheel begins to slip (due either to loss of traction or excessive speed differential), they automatically supply increased power/torque to the opposing driven wheel in order ensure continued motion forward without complete loss of power like what would happen with an open diff.
This effectively allows both driven wheels/axles to maintain contact with whatever surface they’re traversing and prevents one from spinning completely free due excessive speed or lack of traction before full engagement can take place by traditional methods like manual intervention via brakes (which locks up both wheels equally) or downshifting transmission gears (which also increases engine RPMs proportionally). So in short:
Conclusion
If you drive a car with a Posi rear end, you’ll notice that your car handles differently than other cars. Posi rear ends are known for their excellent traction and handling, so if you notice that your car is slipping or sliding more than usual, it’s likely that you have a Posi rear end.
There are a few other things to look for as well, such as increased tire wear and noise from the differential.
If you suspect that you have a Posi rear end, take your car to a mechanic to have it checked out.
