Yukon Gear Tracloc Positraction Clutch Set For 3 Pinion Design For 10.5in Ford

If the rear of your Super Duty, Excursion or E-series van chatters through tight turns, or one rear tire spins on wet grass while the other sits still, the clutch packs inside the factory Trac-Lok limited slip are usually the reason. The Yukon YPKF10.5-PC is a replacement clutch set for the Ford 10.5 inch (Sterling) Trac-Lok carrier of the 3-pinion design. It puts new friction discs and steels back in the factory case so the limited slip works again without buying a new carrier.

What the Trac-Lok clutch set does in a Ford 10.5

The Sterling 10.5 Trac-Lok is a clutch-type limited slip. A clutch pack sits behind each side gear, and spring preload plus the separating force of the gears squeezes those packs so the carrier tries to drive both axle shafts together. In a turn the outer wheel has to overrun, so the discs slip against each other, and every slip wears away a little friction material. Once the packs are thin, the carrier acts like an open diff in low traction. On the wrong oil the discs stick and release in turns, which is the chatter people hear in parking lots. Trac-Lok carriers for this axle come in 2-pinion and 3-pinion versions; this set is for the 3-pinion case, so count the spider gears before ordering.

Symptoms of worn Trac-Lok clutches

• One rear tire spins on ice, mud or a boat ramp while the other does nothing (one-wheel peel)
• Chatter, groan or shudder from the rear in slow, tight turns
• A clunk taking up slack in a turn, often from worn thrust surfaces next to the clutches
• Bronze or friction material on the magnet when the cover comes off
• Chatter that came back soon after a fluid change done without friction modifier

How to confirm before you buy

Start with the fluid. A Trac-Lok on plain gear oil chatters even with healthy clutches, so drain it, refill with the correct gear oil plus limited-slip friction modifier, and drive a few slow figure-eights. If the chatter goes away, the clutches may still have life. If one wheel turns freely with the truck on stands while the other wheel is on the ground, or it still spins on slick pavement, the packs are worn out. If the axle also howls under load, that is a pinion bearing problem with its own fix, and our Ford 10.5 master overhaul kit for 2007-and-older axles covers it in the same teardown. The Sterling 10.5 problems guide walks through the common failures.

Fitment

Yukon lists this clutch set for the Ford 10.5 inch Trac-Lok, 3-pinion carrier, in both the 2007-and-older and the 2008-2010 housings, plus later Super Duty rears. The application rows include F-250 and F-350 Super Duty trucks from 1999, E-250, E-350, E-450 and E-550 vans and cutaways, and the 2000-2005 Excursion. The listing does not give a spline count or ring gear size beyond the 10.5 inch Sterling. Several things change by year: the 2008 housing revision, the 37-spline pinion after 2011, the 2-pinion versus 3-pinion carrier, and some later trucks that run a different axle. Read your axle tag, count the spider gears, and if you are unsure, send us your year and VIN before you order. If you would rather replace the whole carrier, the Yukon Dura Grip for the 10.25 and 10.5 is a complete limited slip.

Install notes

• Pull the axle shafts and carrier, then take the Trac-Lok apart on the bench. The preload spring is under tension, so work it apart with a forcing-screw style limited-slip tool rather than prying. Lay each clutch stack out in order as it comes apart.
• Soak the new friction discs in the gear oil and modifier you will run so they do not chatter when new.
• Inspect the side gears, pinion gears, cross shafts and thrust washers. If teeth are chipped or shafts are stepped, the Yukon 3-pinion 10.5 spider gear kit replaces them in the same job.
• Reinstall the carrier on its original setup and check backlash. Yukon setup specs for the Ford 10.25 and 10.5 list 95 ft-lb on the ring gear bolts and 80 ft-lb on the bearing caps; follow your service manual for carrier bearing adjustment.
• Fill with 75W-90 or 75W-140 gear oil plus friction modifier and seal the cover. A fresh 10.25/10.5 diff cover is cheap insurance if the old one is dented or weeping.

Drive easy for the first few hundred miles and skip heavy towing while the new clutches bed in.

How do I know if my Ford 10.5 Trac-Lok is a 3-pinion design?

Pull the cover and look at the cross shafts. A 3-pinion carrier has three spider gears around the center instead of two. This clutch set is for the 3-pinion case only, so count before ordering.

Will this fix chatter in turns?

If the chatter comes from worn friction discs, yes. A Trac-Lok on the wrong oil chatters even with good clutches, so try a fluid change with limited-slip friction modifier first. If the chatter or one-wheel spin continues, the clutches are worn and this set is the repair.

Which trucks does it fit?

Yukon lists it for Ford 10.5 inch Trac-Lok axles in 1999-and-later F-250 and F-350 Super Duty trucks, E-250 through E-550 vans and the 2000-2005 Excursion, covering both pre-2008 and 2008-2010 housings. Confirm with your axle tag, or send us your year and VIN.

Do I need to reset the ring and pinion when I replace the clutches?

Normally no. The clutches live inside the carrier, so the gear setup stays the same if you reuse the same carrier bearings and adjustment. Check backlash after reassembly, and replace the bearings while the carrier is out if they are noisy.

What fluid does it need?

Use 75W-90 or 75W-140 gear oil with limited-slip friction modifier, and soak the new discs in that oil before assembly.