Yukon Gear 8.8in Ford Tracloc Clutch Set / Both Sides

A Ford 8.8 rear that used to put power to both tires and now leaves a single black stripe, or one that shudders in tight turns no matter how much friction modifier you pour in, has usually worn out its Traction-Lok clutches. The Yukon YPKF8.8-PC-L is a replacement clutch set for both sides of the carrier, the short-ear version Yukon specifies for late-design 8.8 Traction-Lok units in F-150s, Mustangs, Explorers, Rangers and Crown Victorias.

How the clutches work in a Ford 8.8 Traction-Lok

Each side gear in the Traction-Lok carrier has a stack of plates behind it. Plates with tabs, the ears, key into slots in the carrier case. Plates with internal splines ride on the side gear hub. A preload spring between the side gears clamps both stacks, so when one tire loses grip the friction between plates drags torque over to the tire that still has traction. Ear length matters because Ford changed the carrier: early cases use long-ear plates and later cases use short-ear plates. This set is the short-ear design, for both sides.

Symptoms of worn clutch packs

• Only one rear tire spins on wet pavement, gravel or snow
• Chatter or a jerky, skipping feel in slow parking-lot turns that fresh fluid will not cure
• With the rear on stands and the transmission in neutral, one wheel turns easily while the other spins the opposite way
• Dark, burnt-smelling gear oil with gray paste on the drain magnet or cover
• Traction-Lok behavior that faded slowly over many miles, especially after burnouts or towing

How to confirm before you buy

Try fluid first. Drain, refill with the correct gear oil and add friction modifier, then drive a few figure-eights. If the chatter goes away, the plates are still usable. If it stays or the axle acts like an open diff, the clutches are done. Our Ford 8.8 Traction-Lok chatter fix has the full test order, and how much friction modifier to use covers dosing. A howl that changes on and off the throttle is a gear or bearing problem, not clutches.

Fitment

This set fits Ford 8.8 inch Traction-Lok limited slip carriers that use short-ear plates. Yukon labels it for late models; catalog fitment for the 8.8 Mustang runs 1979-2014, and some dealers say it also works in early cases. The reliable check is to pull a plate out of your carrier and compare the ear length to this set. Long-ear early carriers take Yukon's separate YPKF8.8-PC set. It is not for open 8.8 differentials, and it is not the same part as a complete spider gear and clutch kit. If you would rather replace the gears too, see the Ford 8.8 Traction-Lok spider gear and clutch pack kit. Send us your year and VIN if you are not sure what is in your axle, and see the Ford 8.8 rear axle problems guide for the axle versions.

Install notes

• Remove the cover, the cross pin, the C-clips and the axle shafts, then pull the carrier and remove the preload spring and side gears to get at the packs.
• Soak the new plates before assembly. Ford's 1994 Mustang manual calls for lubricating the friction plates with Additive Friction Modifier C8AZ-19B546-A, or an equivalent hypoid lubricant meeting EST-M2C118-A.
• Ford sets pack thickness with a clutch gauge torqued to 60 lb-in on each side and a feeler blade to pick the shim, then bench-checks breakaway torque before the carrier goes back in.
• Inspect the side gear splines, spider gears and the S-spring while it is apart.
• Reseal with a new gasket or RTV, or upgrade to a Yukon steel 8.8 cover or the Hardcore 8.8 cover. Refill with 75W-140 or 75W-85 gear oil per your axle tag, plus friction modifier.
• Doing a pinion job too? A crush sleeve eliminator kit makes pinion preload easier to hold.

Short ears or long ears: which set do I need?

Pull one plate from your carrier and look at the tabs. This YPKF8.8-PC-L set is the short-ear design Yukon lists for late 8.8 Traction-Lok cases. Early cases with long-ear plates take the YPKF8.8-PC set.

Does this set do both sides of the differential?

Yes. It is a clutch set for both side gear packs, so you replace both stacks at once.

Will it fit my open 8.8 differential?

No. It only goes into an 8.8 Traction-Lok limited slip carrier. An open carrier has no clutch packs or slots for them.

Do I need friction modifier?

Yes. Lube the plates with friction modifier before assembly and add it to the gear oil when you refill. Traction-Lok clutches chatter without it.

Can I do this without pulling the axle from the truck?

Yes. The carrier comes out through the cover opening once the axle shafts are out, so most people do it with the axle still in the vehicle on jack stands.