The 8.8-inch Ford rear has plenty of strength and popularity. When you combine its overall strength with the astronomical number of 8.8-inch rear parts produced for Ford passenger cars, trucks and SUVs, you understand the motivation of the performance aftermarket to develop it even further.

Historically, performance enthusiasts and racers have embraced important components such as engines, transmissions and rears in an “sweet spot” of mass availability. Compared to the 9-inch Ford rear that ceased original production around 1986, the 8.8-inch rear was placed in high-production vehicles from 1985 until recently, meaning they are now in older vehicles sitting in cemeteries.

Two of the main performance manufacturers used for versions 8.8 by the Horsepower Wars teams are Moser Engineering and BMR Suspension. We specifically tracked the build of Team Out in Front’s $ 10,000 Drag Shootout 1996 Mustang “White Boy Rick”. Both companies have played an active role in providing expertise for their ‘bang per buck’ racing car lens.

“Surprisingly, the rear of the OEM 8.8 factory is starting to clear up when it comes to easy scrapyard access,” says Jeff Anderson, Marketing Director at Moser Engineering. “With the continued popularity of 8.8, we decided to produce a new case and improve some areas where the original 8.8 was lacking. “

So, after Moser’s engineering efforts are over, they now offer an aftermarket 8.8 case with modular molding, increased strap, and enlarged axle tube diameter. “Although it was generally strong, the 8.8 had smaller axle tubes,” says Anderson. “The only way to get a performance three-inch tube in the middle section is to pierce the molding, which weakens it. Some use a small tube with a larger three-inch tube welded to the outside, but this does not add maximum strength to the rear assembly.

Since the General Motors 12-bolt differentials of the 1960s, racers had to retain stronger axles than the small factory clips used inside the differential. The strongest method is based on an older Ford axle design that uses a pressure ring at the outer bearing of the axles. – Jeff Anderson, Moser Engineering

Invest wisely

Since Team Out in Front’s Mustang 96 was originally a V6 model, they found a scrap case of a comparable Mustang GT and beefed it up as best they could. This bolt-on replacement better accepts high-strength internal components from Moser Engineering.

The 2020 $ 10,000 Drag Shootout season followed a “no prep” competition setup, so the team was betting on less stress on the factory-diameter axle tubes. This upgrade also offers a nearly bolt-on suspension setup using BMR suspension components.

“BMR suspension control arms are available in several configurations, including upper and lower sets with adjustable dual chrome-molybdenum rod ends, heavy-duty spherical rod ends and those equipped with poly bushings,” Kyle describes. Briese from BMR. “Our rear suspension arm assortment also offers options with or without spring perches and with single and double adjustable ends.”

Marcus Thompson and his team aimed to build a Mustang for competition. The team has extensive experience in getting the Fox-body platform to handle great powers, but with reasonable suspension modifications. Extra money was spent on dual tuning coil spring racing shocks from QA1 Precision Products to give the rear suspension the necessary adjustment for the brake band.

Compared to chrome-molybdenum connecting rod ends, performance enthusiasts who drive on the streets can opt for the suspension arms with spherical bearing ends. These stainless steel bearings are designed to withstand the highest compressive loads while also supporting everyday use. If you want to improve performance over the stock control arms, but with a quieter ride, polyurethane bushing arms would be your choice.

Another crucial piece of BMR performance hardware to get the most out of the factory Mustang suspension design will be the relocation brackets for the lower control arms.

“Our relocation brackets bolt directly to the original lower suspension arm bracket on the housing,” notes Frank Steadman of BMR. “These brackets have three mounting positions, so you can change the instantaneous center point with the geometry of your control arm. When high power is put on the ground, changing this lower suspension arm angle can control wheel jump and provide better launch characteristics.

The last part used on “White Boy Rick” was a prototype anti-roll bar that BMR had created exclusively for the $ 10,000 Drag Shootout, which bears a striking resemblance to the production S197 anti-roll bar proven on streetcars from 7 seconds. This 1.375-inch DOM anti-roll bar kept the Mustang’s launch flat, even, and controlled on the surface without preparation using 28 × 10.5-inch Mickey Thompson slicks. In fact, it worked so well that BMR has since decided to put it into production.

A-Back Forging

The team welded the ends of the 8.8-inch Mustang Moser non-C-clip housing to the Mustang GT housing. These housing ends will accept the larger 35-spline Moser axles and associated spool. Jeff Anderson explains the elimination of factory axle retaining clips with this combination of components.

“By not relying on the C-clips to hold the axle, you keep the axle and wheel from coming out of the vehicle,” Anderson describes. “Once you achieve a certain level of performance in any form of racing, the governing bodies mandate the use of C-clip eliminators for obvious safety reasons.”

With the suspension changes underway, other members of the five-person team focused on finishing the internal components of the differential. Each of the $ 10,000 Drag Shootout teams have this “one man” knowledgeable about this process, including the proper ring and pinion mesh adjustments.

What the teams were looking for at this point was to achieve the definition of a proper gear set. This clearance is “the gap and spacing between the pinion tooth and the ring gear”. This gear and tooth contact allows for a necessary film of lubricant between the meshed gears.

Team Out in Front chose a 3.55 ratio bushing and pinion gear and used a Moser R88 setup kit that provided all of the components needed to perform a new bushing and pinion installation. Kit includes differential and pinion bearings (including all associated bearing cups and cones), plus pilot bearing, pinion support shims, adjustable pinion collar, pinion seal, nut pinion, gasket, gear marking compound and crown bolts.

Following the simple 8.8 differential assembly procedure, the pinion is first installed into the housing with a pinion depth tool. You can use an OEM style crush collar to adjust the depth of the sprocket, or in the case of a dragstrip fit assembly, a strong spacer is installed and adjusted for depth with strong shims.

The ring gear and spool are placed in the housing with all Moser differential bearings, cups and cones. Once the bearing caps were tightened in place, they added another critical Moser component increasing the resistance by 8.8 exponentially, a Moser Performance gear cover. Not just any standard stamped metal cover meant to hold gear lubricant, this is a cover made from heavy 356-T6 machined aluminum.

“I always say to enthusiasts, regardless of the power, if you lean on the damper often enough, a performance bag will help you in a number of ways,” says Anderson. “At the end of the day, you’re trying to stop any flex in your ring and pinion when you apply power. This is a very common source of back failure.

Anderson concludes: “Essentially, your ring gear wants to push back your differential bearing caps with tremendous force. The sturdy cover combined with the heavy set screws prevent these caps from sagging.

To wrap up

Even with quite different components that BMR and Moser each offer for the rear of the Ford 8.8, it’s obvious both companies think it’s here to stay as the performance cornerstone. Whether it’s modifications that keep this rear design well ahead of the power thrown at it or suspension parts that transfer that power to the ground, the Out in Front Mustang team exemplifies these positive attributes.

Sit back and enjoy the $ 10,000 Drag Shootout 3 at HorsepowerWars.com and see how these four teams implement the Ford 8.8 rear into their individual entrances. As for the final bouts of race day, the 8.8 handled all the power their various turbocharged powertrains could throw at them.