How to Make a Ford 8 Inch Rear End Posi

Converting a Ford 8-inch rear end to a posi-traction (limited-slip) differential involves a series of steps. Please note that working with automotive components requires skill and knowledge, so if you are not experienced in this area, it is recommended to seek the assistance of a professional mechanic. However, I can provide you with a general overview of the process involved.

Here Are the Steps to Make a Ford 8-Inch Rear End Posi:

1. Gather the Necessary Parts:

You will need a posi-traction differential unit designed for the Ford 8-inch rear end. This component is often referred to as a “Posi” or “Limited-Slip” unit. Additionally, you will require a master overhaul kit, which typically includes bearings, seals, gaskets, and other necessary components for a complete rebuild.

2. Lift the vehicle:

Use a floor jack or a vehicle lift to raise the rear end of the vehicle, ensuring it is secure and stable on jack stands. Make sure to follow proper safety precautions when working under a vehicle.

3. Remove the rear wheels:

Take off the rear wheels to access the rear differential housing.

4. Drain the differential fluid:

Locate the differential cover, typically at the rear of the housing, and carefully remove it to drain the fluid. Ensure you have a suitable container to catch the fluid.

5. Remove the differential assembly:

Inside the differential housing, you will find the ring gear, pinion gear, and spider gears. Carefully disassemble these components, following the manufacturer’s instructions. Take note of the positioning and orientation of the gears for reassembly.

6. Install the posi-traction unit:

Remove the open differential carrier and replace it with the posi-traction differential unit. Ensure proper alignment and fitment, following the manufacturer’s instructions and specifications.

7. Reassemble the differential:

Put the ring gear, pinion gear, and spider gears back into the housing, following the manufacturer’s instructions for proper installation and gear mesh. This step may require adjusting the ring gear backlash and checking the gear tooth pattern for correct alignment.

8. Replace seals and bearings:

Install new seals and bearings included in the master overhaul kit, following the manufacturer’s instructions. This step ensures proper lubrication and prevents leaks.

9. Reinstall the differential cover:

Clean the mating surface of the differential housing and the cover, then use a new gasket or sealant to secure the cover back onto the housing. Torque the bolts to the manufacturer’s specifications.

10. Refill with fluid:

Use the recommended differential fluid type and fill the rear end with the appropriate amount of fluid, as specified by the vehicle’s manual or the differential manufacturer.

11. Reinstall the rear wheels:

Put the rear wheels back onto the vehicle and ensure they are tightened to the manufacturer’s specifications.

12. Lower the vehicle:

Carefully lower the vehicle from the jack stands or vehicle lift.

Once the process is complete, it is essential to test the posi-traction functionality by driving the vehicle carefully and observing its behavior during turns and acceleration. If you encounter any issues or have concerns, consult a professional mechanic for further assistance.

Rebuilding Damaged Ford 8 inch Rear End. Upgrading to Traction Lock and 3.55 Gears.

Ford 8 Inch Rear End Limited Slip

The Ford 8-inch rear end is one of the most popular axle assemblies used in street rods and muscle cars. It’s strong, reliable, and can be had with a limited slip differential. In this article we’ll discuss the benefits of a limited slip rear end and how to install one in your Ford 8-inch rear end.

A limited slip differential (LSD) is a type of differential that allows both wheels to rotate at different speeds while still providing traction to both wheels. This is accomplished by using clutch plates or cones that are engage when one wheel starts to spin faster than the other. This limits the amount of slippage that can occur between the two wheels and helps provide better traction, especially when starting from a dead stop or when making turns on slippery surfaces.

Installing an LSD in your Ford 8-inch rear end is not difficult, but it does require some special tools and knowledge. We recommend having a professional mechanic or hot rod shop do the installation for you if you’re not comfortable doing it yourself. But if you’re up for the challenge, here’s what you’ll need to do:

1) Remove the old diff cover and drain the gear oil into a catch pan. Remove the ring gear bolts and carefully remove the ring gear from the carrier housing. Be careful not to damage any of the bearings as you remove them.

2) Clean all of the old sealant off of the mating surfaces of both the housing and ring gear using a solvent such as lacquer thinner or brake cleaner. You want these surfaces to be absolutely clean before proceeding any further.

3) Install your new LSD unit into place following instructions provided by manufacturer (these will vary depending on which LSD unit you purchase). Make sure everything is properly torqued down according to spec before continuing. At this point it’s also a good idea to install new bearings (if included with your LSD kit) as well as any new races that might have come with it as well.

4) Reinstall your ring gear onto carrier being careful not damages any shims or bearings in process (consult manufacturer’s instructions for proper torque specs).

5) Fill differential with correct amount and type of lubricant per manufacturer’s recommendations (this info should also be stamped somewhere on diff cover itself).

How to Make a Ford 8 Inch Rear End Posi


Can You Convert a Rear End to Posi?

The most common type of posi is the limited-slip differential, which uses clutch packs or cones to allow some slip while still providing mostly traction. To convert a rear end to posi, you’ll need to install a Posi unit into the differential. This will usually require some disassembly of the differential itself.

Once the Posi unit is installed, your rear end will have increased traction and better performance.

How Do I Know If My Ford 8.8 is a Limited-Slip?

When it comes to your Ford 8.8, there are a few ways that you can tell if it is a limited-slip. First and foremost, you’ll want to check the markings on the differential itself. If it is marked with an “LS,” this indicates that it is a limited-slip.

You can also tell by looking at the clutch packs inside the differential. If there are two clutch packs, then it is a limited-slip. Finally, you can take your car for a spin and see how it behaves when making tight turns.

If the rear end feels like it wants to come around, then you likely have a limited-slip differential.

What Gear Ratios are Available for a Ford 8 Inch Rear End?

Assuming you are asking about a stock Ford 8-inch rear end, there were three gear ratios available: 2.80, 3.00, and 3.50. The most common ratio was the 3.00, followed by the 2.80; the 3.50 was less popular because it produced higher engine speeds on the highway and thus lower fuel economy. There were also aftermarket gear sets available with ratios as low as 2.50 and as high as 4.11; these were mostly used for drag racing or other specialized applications where very high or very low gearing was desired.

Is Ford 8.8 Limited-Slip?

If you’re looking for a reliable and affordable limited-slip differential, the Ford 8.8 is a great option. This differential was first used in the 1999 Ford Explorer and has since been used in a variety of other vehicles. It’s known for its strength and durability, making it a popular choice for off-roaders and those who tow frequently.

The 8.8 limited-slip differential uses clutch plates to provide extra traction when one wheel starts to slip. This can be extremely helpful when driving in slippery conditions or when one wheel is on a loose surface like sand or gravel. The downside of this design is that it can be noisey and may require more maintenance than an open differnetial.

If you’re considering a Ford 8.8 limited-slip differential for your vehicle, be sure to do your research to see if it’s the right fit for you.


If you have a Ford 8 inch rear end in your car, you may want to consider making it a posi. This will allow both wheels to receive equal power from the engine, rather than one wheel getting more power than the other. Here are some steps to help you make your Ford 8 inch rear end posi: