(approx) 4 Hours
Mechanical expertise or professional installation required.
Hey, guys. Today we're gonna be taking a look at the Eaton 31 Spline 8.8 Limited Slip Differential, for '86 to 2014 V8s and 2011 to 2014 V6 Mustangs. This is a Posi unit. It's gonna be a good option for the guys out there with an 8.8 rear that are looking to replace their diff with the next upgrade over stock and that want a performance-oriented name like Eaton. Eaton tends to be on the more expensive side, but it is a proven name in the aftermarket performance world. This diff costs about 550 bucks. It has carbon disks and it requires the use of 31 spline axles, which gives it that upgrade over the factory components. And if you're planning on, or already have some bigger power and torque numbers from your Mustang or the car sees track time or hard launches, a differential upgrade should be something that you're looking into. When it comes to the install, I'm gonna call it a full three out of three wrenches on the difficulty meter.If we take a step back for a minute and look at the need for a limited slip diff, I'd say that the point of a limited slip differential or LSD like this one here, is to allow both rear wheels to put power to the ground and give better traction to both rear wheels. So, the thought is if there's any type of open diff transfer or an uneven transfer of power and torque to one particular wheel over the other that'll create a useless wheel spin where the car loses its forward momentum, the LSD is designed to eliminate this spin. It will transfer the torque of both wheels evenly, which will have a few benefits in both street and track applications. This means a stable differential lock pattern that won't fail due to the upgraded components, no slipping, more durability, gentle transitions, and even a quiet operation.There are a couple of reasons to change or upgrade your differential. Maybe you've got a stock diff and it's just getting old and chattering or maybe you plan on hitting the drag strip and you've got some power that you'd like to cleanly get to the ground. Maybe you have a V6 and you're looking to upgrade to an 8.8 setup, and maybe you have a V6 that just needs a heartier rear diff. Either way, this Eaton diff would be a good option because it's got a balance of being an upgraded part that can handle more power and torque, but it isn't such an upgrade that it wouldn't make sense for a completely stock car to upgrade to. It's also user-friendly for streetcars. This diff is gonna require the use of 31 spline axles. So, if you've got an '04 and under V8, you're looking at upgrading your axle since those cars did come with factory 28 splines. If you've got an '05 and up, you can reuse your factory axles with this diff, but you are still looking at an upgrade due to the fact that this diff has carbon disks.The carbon fiber disks that I keep referencing to refers to the clutch pack. This diff uses the carbon friction plates because they're much more durable and they're designed for higher torque than the factory stock friction plates. This is gonna work for cars with both solid axle and IRS or independent rear suspension, and you will need to reuse or grab a new 8.8 rear gear set. This diff won't come with aftermarket rear gears. One other note would be the recommended use of 75W rear gear oil for street use since this will give me the same oil weight as factory. And you are gonna need 3 quarts and 4 ounces of friction modifier for the initial fill. For colder temps or for race use, you can try 75/140. This diff will not work for the '99 to '04 Cobra or the '13 to '14 GT500 either. So, just be aware of that.When it comes to the install, I said it earlier but this is gonna be a full three out of three wrenches in the difficulty meter. In a lot of cases, this will be a shop install but it's not impossible to do at home either.If you guys are interested in this Eaton LSD, you can always check it out more online right here at americanmuscle.com.
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Features, Description, Reviews, Q&A, Specs & Installation
Technical Note. You will need to reuse your factory 8.8” gear set, or upgrade to a set of our 8.8" rear gears required for this Limited Slip Differential. No aftermarket gears are included. For normal driving conditions we recommend you use 75W 90 rear gear oil. This will give you the same oil weight as factory. For colder temps or race use try 75w 140.
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November 18, 2018
Very happy with this purchase. Had a loca shop install diff with new gears, new axle bearings, and new diff cover. Car feels much more stable. Even while tires are spinning, car goes forward in a straight line. Great purchase.Helpful (6)
June 18, 2018
Works great so far. I really like it better than the mini spool it was in my car.Helpful (6)
April 06, 2018
Now this is amazing. Both wheels spin and hook hard. I never knew this could help your car go faster but it does. Bog bang for your buck. This has carbon fiber clutches so its really strongHelpful (5)
March 18, 2018
Amazing difference in traction. My factory diff started slipping at the track. After getting it up on jack stands and testing the rear end, there is a night and day difference between the 2. The car launches much straighter and harder than it ever has. It will be nice to see the difference in my 60’ times. It was a toss up between the Easton and the Yukon. Both seemed to be a very nice part but the Eaton seemed to be the choice of most people. The Yukon seemed to have more negative reviews than the Eaton. I am pleased with this part but only time will tell on how good or bad it truly is.Helpful (8)
June 23, 2017
This differential made a world of difference.. it's not call Eaton for no reason cause this bad boy EATS the street like a true track monster! Better control and no one wheel wonders period.Helpful (7)
May 20, 2016
2011 Ford Mustang
Well not mush to say, but the Eaton Differential works very goodHelpful (6)
September 28, 2015
I'll give a better review when it breaks.
I put the Eaton unit in as a replacement for a failed ford racing unit. Also put in Moser 31 spline axles, ford racing 3:83 gears, and a ford racing aluminum driveshaft, with the Steeda diff cover to finish things off. Everything went in well and I'm still in the break in. There's no unusual noises or anything else out of the norm. I'll post an update when it breaks.Helpful (8)
August 22, 2014
Eaton Differential Install
This was a very easy install and seems to have improved the performance of my Mustang some. Acceleration is straight and true with very little tire spin unless I really get on it.Helpful (5)
July 18, 2014
strong and reliable
Product is strong and reliable I have had zero issues with itHelpful (7)
June 13, 2014
great limited slip
this limited slip works just fine for me and my twin turbo 2011 GT at around 800hp and 800ftlbs.Helpful (8)
push button traction control what if any upgrades will i have to do to the "push button traction control". i want to also put 3.73 gears in. just dont want to mess anything up
No upgrades or modifications are required. Traction control is a system that actually operates through the rear brakes; during moments of wheel spin, the T/C system rapidly engages the rear brakes in order to slow down the wheels until traction has been regained. If you change your gears, make sure you get your car tuned.
I have one of these in my rear end and there seems to be about an 1/8 inch of play in and out for each axle shaft and a clunk going down the road that is definately coming from somewhere in the rotating assembly. Is this amount of play normal or might it need rebuilt/do they make a rebuild kit? I have no clue how old it is/the number of miles. The u joints/ driveshaft appear straight and in good shape.
The 8.8" rear should have approximately 1/8" of axle end play when properly set up. The noise may be a bearing issue, or a gear issue.
What gear oil does it require and any additive or anything
The Eaton Limited Slip Differential should run your stock weight gear oil to maintain proper lubrication of the ring and pinion gears. We do recommend a friction modifier as this is still a clutch type differential.
What is the difference with the 3.7 mustang differential to the limited slip differerential? I have 4.10 gears installed in my 2012 mustang 3.7, and wanted to know the difference between the stock differential for my car to this limited slip differential? Would it be beneficial to my car? If so, how?
If you already have limited slip no difference but if you have a standard differential. A limited slip will more regularly put power to both wheels you won't notice any difference unless you have wheelslip problems
Is this part required when upgrading from 2.73 factory gears to ford racing 4.10 gears? I want to upgrade my gears for faster acceleration and was just needing to know that when I purchase the gears, will I have to purchase the limited slip differential. I own a 2013 V6 Mustang with stock 2.73 gears. I want to upgrade to 4.10's. Thanks! Jeramie
No you don't need an upgraded differential. It would give you better grip to go with an upgraded diff., but its not required.
(approx) 4 Hours
Mechanical expertise or professional installation required.
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