Yukon Gear Positraction internals For 8.8in Ford w/ 28 Spline Axles
If you run a Yukon Dura Grip or an Eaton posi in a 28-spline Ford 8.8 and it has started to clunk, or you found a chipped tooth when you pulled the cover, you do not need a whole new carrier. The Yukon Gear & Axle YPKF8.8-P-28 is the replacement spider gear set for those aftermarket limited slips in the 28-spline 8.8, the axle found in plenty of Mustangs, Crown Victorias and Rangers. It is a gear-side rebuild only: it does not include clutches, and Yukon notes it does not fit the factory Ford limited slip.
A Dura Grip is a clutch-type limited slip. The clutch packs sit behind each side gear and provide the locking bias, but the spider gears carry the torque. The ring gear turns the case, the case turns a cross pin, two pinion gears on that pin drive the two side gears, and the side gears are splined to the axle shafts. Under throttle the pinion gears push the side gears outward into the clutch packs, which is how the unit clamps up and drives both tires. That means the gear teeth and cross pin take every launch and every wheel-hop hit. On a C-clip 8.8 the cross pin is also what keeps the axle C-clips in place. Yukon's set includes two side gears, two pinion gears, the cross pin shaft, the roll pin and the spider gear thrust washers.
Chatter in tight turns or one tire spinning again usually means worn clutches or tired oil, not the gears. Our 8.8 chatter guide covers when an oil change and additive is enough, and the spider gear failure guide covers what broken gears look and sound like.
First, confirm what carrier is in the axle. This set is for the Yukon Dura Grip and Eaton posi units. A factory Traction-Lok, with its S-shaped preload spring between the side gears, is a different design; if that is what you have, the Ford 8.8 Traction-Lok clutch kit is the usual repair. Second, pull an axle and count splines. This is 28-spline only. Many trucks and SUVs with the 8.8 use 31-spline shafts, and our 28 vs 31 spline guide shows how to check.
Fits the Ford 8.8 in. axle with 28-spline shafts that is already fitted with a Yukon Dura Grip 28-spline 8.8 posi or an Eaton posi. The vehicle year matters less than what is inside the case, because the gear set fits the carrier, not the car. Do not order it for an open 8.8 or a factory Traction-Lok. If you are unsure which carrier you have, send us a photo of the case with the cover off along with the year and VIN, and we will confirm before it ships. Ring and pinion sets, carriers and other 8.8 internals are on our hard parts page.
Drain the oil, remove the cover, drive out the roll pin and slide out the cross pin. Push the axles in, remove the C-clips and slide the shafts out a few inches. On a clutch posi the side gears are held against spring preload, so the gears are rotated out of the case window rather than lifted; Yukon's Dura Grip instructions and a posi gear rotating tool make this far easier. Inspect the clutch packs while they are exposed and replace them if the friction material is worn or glazed. Coat the new gears and washers with gear oil, rotate them into place, then reinstall the C-clips, cross pin and a new roll pin. The ring gear is not moved, so backlash should be unchanged; Yukon's chart lists 0.006 to 0.011 in. for the 8.8. Refill with a non-synthetic GL-5 gear oil and limited slip additive, as Yukon specifies for the Dura Grip.
If the bearings are noisy too, the Yukon master overhaul kit for 2009-and-older 8.8 covers bearings, seals and shims in one box.
| Brand | Yukon Gear & Axle |
| Part number | YPKF8.8-P-28 |
| Fits | Yukon Gear Positraction internals For 8.8in Ford w/ 28 Spline Axles |
| Type | Ring & Pinions |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Yukon states it does not fit the factory limited slip. It is for the Yukon Dura Grip and Eaton posi units in the 28-spline Ford 8.8.
No. The set includes two side gears, two pinion gears, the cross pin shaft, the roll pin and the spider gear thrust washers. Clutch packs are sold separately.
No. The side gears are cut for 28-spline axle shafts. Count the splines on the inner end of an axle before ordering.
Usually not. The cross pin and C-clips come out with the carrier in place, and the gears rotate out through the case window.
Yukon recommends a quality non-synthetic GL-5 gear oil with its limited slip additive. Synthetic oil can make the composite clutches grab or chatter.
