Yukon Gear 14 Plate Duragrip Composite Clutches For GM 8.2in / GMin / 12T / 12P / Ford 8.8in

A Yukon Dura Grip that used to put power to both tires but now lets one spin on wet pavement, or that has started to bang and chatter in parking lots, usually needs fresh clutches rather than a new carrier. Yukon YPKGM12-PC-DG1 is the 14-plate composite clutch set Yukon lists for its Dura Grip positraction in the GM 8.2 inch, GM 8.5 inch, GM 12-bolt truck (12T) and passenger car (12P), Ford 8.8 inch and cast iron Corvette rears. This is a clutch pack, not a gear set; the carrier, spider gears and ring and pinion are not included.

What the clutches do in a Dura Grip

Yukon builds the Dura Grip with a nodular iron case, forged 4320 chromoly spider gears and composite clutches, and designs it to be rebuilt. A stack of plates sits behind each side gear. Some plates are locked to the side gear and the rest to the case, and spring preload squeezes the stack together. When one tire starts to slip, the friction in those stacks resists the speed difference and sends torque to the tire with grip. In a normal turn the outside wheel overcomes the clutch friction and the axle drives smoothly. As the composite plates wear thinner, preload drops and the unit acts more and more like an open differential. Replacing the clutch set restores that preload without paying for a whole new case.

Symptoms of worn Dura Grip clutches

• One tire spins on a wet launch, a boat ramp or gravel where both used to pull
• Shudder, groan or stick-slip chatter in slow tight turns, often worse after a fluid change done without additive
• The carrier turns too easily in the wheel-spin test described below
• Clutch material or dark friction dust in the drained oil and on the cover magnet
• A clunk taking up slack when you get back on the throttle in a turn, if the clutches have worn enough to let the side gears move

How to confirm before you buy

With the rear on stands and the transmission in neutral, turn one tire by hand. On a healthy clutch-type limited slip the opposite tire should want to follow in the same direction; if it spins freely the opposite way like an open axle, the clutches have lost their bite. Chatter alone can be fluid, so try a correct gear oil and friction modifier first. Our friction modifier guide covers the dose, and the open vs limited slip vs locker guide explains how each type should behave.

Fitment

Yukon lists this set for Dura Grip positraction units in these axles: GM 8.2 inch, GM 8.5 inch, GM 12-bolt truck and passenger car, Ford 8.8 inch and the cast iron Corvette rear. Make sure what you have is actually a Yukon Dura Grip, such as the Dura Grip for the Ford 8.8 with 31-spline axles or the GM 8.5 Dura Grip. A factory Ford Traction-Lok is a different design; for that carrier use the Traction-Lok clutch kit instead. Count the plates per side and compare the tab shape of your old plates to the new ones before you start, and send us the axle and carrier details if anything does not match.

Install notes

• The carrier has to come out of the housing. Mark the bearing caps and record backlash so the ring gear goes back in the same position.
• Lay the old plates out in the exact order they came out of each side so the new stack is assembled the same way.
• Soak composite plates in the gear oil you will run, and lube them before assembly so they do not start dry.
• Check the spider gears, cross shaft and thrust washers while the case is apart. Worn spiders will chew up new clutches quickly.
• If the carrier bearings are rough or the gears are noisy, this is the time to fit a Ford 8.8 carrier installation kit. Our 8.8 chatter fix guide also covers what else to check on that axle.
• Refill with a gear oil suited to limited slips. On its Dura Grip pages Yukon recommends a non-synthetic GL-5 plus limited-slip additive.
• Drive easy for the first few hundred miles while the new plates bed in, then recheck the fluid level.

Will this kit fit my factory GM Positraction or Ford Traction-Lok?

Yukon lists it for its Dura Grip positraction in these axle sizes. Factory carriers often use different plates, and the Ford Traction-Lok has its own clutch kits, so compare plate count and tab shape before buying.

Does it include spider gears or a new case?

No. YPKGM12-PC-DG1 is the clutch set only. Inspect your spider gears and cross shaft while the carrier is apart and replace them if worn.

Why does my limited slip chatter in tight turns?

Usually the clutch stack is grabbing and releasing. Fresh gear oil with the right amount of friction modifier often cures it. If chatter returns quickly or the unit has lost its bite, the clutches are worn.

What gear oil should I use with these composite clutches?

Yukon recommends a non-synthetic GL-5 gear oil plus limited-slip additive for its Dura Grip units. Use the viscosity listed for your axle.

Do I need to reset the gear pattern after replacing clutches?

If the same ring gear, carrier and bearings go back in with the original shims, backlash should return to where it was. Measure it before and after to be sure.