Yukon Gear Positraction internals For 7.5in and 7.625in GM w/ 28 Spline Axles

This is the replacement spider gear set for a Yukon Dura Grip positraction in a GM 7.5 or 7.625 ten-bolt rear with 28-spline axle shafts, the axle found under S-10 and Blazer trucks, Camaro and Firebird, Monte Carlo, El Camino and many other GM half-ton and passenger car applications. If your Dura Grip clunks in turns, has sloppy play at the wheels, or showed chipped gear teeth when you pulled the cover, Yukon part YPKGM7.5-P-28 replaces the gears inside the case without buying a whole new carrier. Note the listing name says positraction internals: it is the gear set, not the clutches.

What the spider gears do in a GM 7.5 Dura Grip

The Dura Grip is a clutch-type limited slip. The two side gears are splined to the 28-spline axle shafts, and the two pinion (spider) gears ride on a cross pin between them so the wheels can turn at different speeds in a corner. Spring preload pushes the side gears outward against clutch packs, which is what sends torque to the tire with grip. The gears and their thrust washers carry every bit of axle torque, and when they wear the backlash between them grows, so you get a clunk on and off the throttle and the clutches lose their preload. Yukon lists this kit as two side gears, two pinion gears, the cross pin shaft, the roll pin and the spider gear thrust washers.

Symptoms of worn spider gears

• Clunk when turning or when shifting from drive to reverse
• Excess rotational play: with the driveshaft held, a rear wheel rotates a noticeable amount before it catches
• Chatter or binding in slow, tight turns
• One-wheel spin that gets worse as the gear set and washers wear
• Chipped teeth, a scored cross pin or worn thrust washers once the cover is off

How to confirm it before buying

Pull the cover and drain the oil. With the rear on stands and the transmission in park, turn one wheel by hand and watch the spider gears. Look for chipped teeth, a grooved cross pin and thin or scored washers. If the clutches are the only worn part (chatter in turns with good gears), you need a clutch kit instead. Confirm it is a Yukon Dura Grip: this gear set is made for the Dura Grip only and Yukon states it does not fit the factory limited slip. Also confirm the shaft spline count. GM 7.5 shafts came in 26 and 28 spline, and the 28-spline shaft is the 1.20 in diameter version.

Fitment

Fits GM 7.5 and 7.625 rear axles with a Yukon Dura Grip positraction and 28-spline axles. It does not fit 26-spline axles, factory GM limited slips, or open carriers. If you have a factory open diff and want traction, start with a complete carrier such as the Yukon Dura Grip for GM 7.625 with 28-spline axles or the Eaton Truetrac for GM 7.5/7.625 28-spline. Not sure what is in your axle? Send us a photo of the carrier or the year and VIN and we will check before you order.

Install notes

• This is a C-clip axle. Remove the cross pin, push each axle shaft in, pull the C-clips, then slide the shafts out far enough to clear the side gears.
• Follow Yukon's Dura Grip instructions for removing the preload springs and rolling the old gears out of the case window. Keep the clutch packs in order if you are reusing them.
• Coat the new gears and thrust washers with gear oil, roll them in, then fit the new cross pin and drive in the new roll pin.
• If the axle has noise or mileage, do the bearings while it is apart with the GM 7.5/7.625 master overhaul kit or the GM 7.5 bearing kit. Revolution Gear lists GM 7.5-7.6 ring gear bolts at 65 ft-lb and caps at 60 ft-lb.
• Refill with 75W-90 gear oil and add limited-slip friction modifier for the clutches unless the oil already contains it.

Does this kit include clutches?

No. Yukon lists YPKGM7.5-P-28 as two side gears, two pinion gears, cross pin shaft, roll pin and thrust washers. Clutches are sold separately.

Will it fit the factory GM limited slip in my 7.5?

No. Yukon states this set is for the Yukon Dura Grip only and does not fit the factory limited slip.

How do I tell 26-spline from 28-spline axles?

Count the splines on the end of an axle shaft, or measure it. The 28-spline GM 7.5 shaft is 1.20 in in diameter; the 26-spline shaft is smaller. This kit is 28-spline only.

Do I have to reset ring gear backlash?

Not if the carrier stays in the housing. The axles and C-clips come out, and the gears roll out through the case window. If you remove the carrier for bearings, check backlash on reassembly.

What gear oil does it need?

Use 75W-90 gear oil with limited-slip friction modifier for the Dura Grip clutches, unless your oil already includes the additive.

Which vehicles use the GM 7.5 and 7.625?

Common ones are the S-10 and S-15, Blazer and Jimmy, Camaro and Firebird, Monte Carlo and El Camino, plus many other GM cars and light trucks. Confirm by the 10-bolt cover, the axle code, and a 7.5 in ring gear.