Restores lockup in a worn Ford 7.5 or 8.8 Traction-Lok limited slip: new clutch discs, steels, shims, pin bolt and friction modifier in one kit.
The M-4700-B is the Ford Performance service kit for the 8.8-inch Traction-Lok limited slip, the axle under 1986-2014 V8 Mustangs, 1983-2014 F-150s, 4.0L Rangers, 1991-2001 Explorers and the Crown Victoria, Grand Marquis and Town Car. If your rear end has gone lazy and lays down one stripe instead of two, or the inside tire chirps and the axle binds in tight turns, this kit puts fresh clutch packs, the selective shims to set them up, a new cross-pin lock bolt and Ford friction modifier into the carrier you already own.
Inside the 8.8 Traction-Lok carrier, each side gear has its own stack of friction discs and steel plates sitting between the gear and the carrier wall. An S-shaped preload spring wedged between the side gears pushes both stacks outward, so the axle shafts are always lightly tied to the case. Under power, the separating load from the spider gears clamps the stacks harder, which is what sends torque to the tire with grip. The shim behind each pack decides how tight that stack starts out. Once the discs wear, the stack shrinks, spring pressure falls and the axle behaves like an open differential. Replacing the discs and steels and re-shimming restores the original clamp.
Whine on acceleration or coast is not a clutch problem; that is pinion or carrier bearing wear, covered by the 8.8 master bearing and seal kit.
First read the axle tag on the cover bolt or the door-jamb axle code to make sure the car actually left the factory with a limited slip. Then drain the oil and refill with gear oil plus friction modifier; chatter that came from a modifier-free fluid change often goes away there. If one tire still spins or the hand check shows the wheels turning in opposite directions freely, the packs are worn and the kit is the fix. Count axle splines while the shafts are out: 28 and 31 spline both run on this kit, but the side gears in your carrier must match your shafts.
Ford lists the M-4700-B for 8.8-inch Traction-Lok differentials built before the 2015 Mustang. It does not fit the 2015-and-later Super 8.8, which you can spot by its 12-bolt cover instead of the usual 10 bolts. The 1993-1995 SVT Lightning used its own Traction-Lok kit, and the smaller 7.5-inch axle is a different carrier, so confirm with the axle tag before ordering. Send us the year, model and axle code or VIN if you are unsure. Other parts for this axle are on the rebuild kits page.
Shopping for a racing cross pin while the cover is off? The Spartan Locker cross pin is a different conversion, not a Traction-Lok part. A budget alternative to this Ford kit is the 8.8 Traction-Lok clutch pack kit.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Those use the Super 8.8, which has a 12-bolt cover and different internals. Ford lists this kit only for 8.8 Traction-Lok units built before the 2015 Mustang.
Yes. Ford lists a bottle of friction modifier in the kit along with the clutch pack, shims and the cross-pin lock bolt with thread lock.
Yes, the clutch discs and steels are the same for both. Your existing side gears must match your axle shafts, and those stay in the carrier.
Usually not. The packs come out through the cover opening once the cross pin, C-clips and S-spring are removed. You only pull the carrier if you are also doing bearings or gears.
Not always. Change the gear oil and add friction modifier first. If the chatter returns, or one wheel still spins under power, the plates are worn and this kit is the repair.
