Yukon Gear Yoke For GM 9.5in w/ A 1350 U/Joint Size

The GM 9.5 in. semi-float 14-bolt sits under a lot of older Chevrolet and GMC 1500 and 2500 pickups, Suburbans, Tahoes, Yukons and full-size vans, and after a few hundred thousand miles the pinion yoke is often the reason the rear end leaks or clunks. The Yukon Gear & Axle YY GM15579602 is a direct replacement rear pinion yoke for that axle: 30 splines, sized for a 1350 series U-joint, strap style. If you are chasing a pinion seal leak that will not stop, a clunk when you drop it into gear, or a yoke damaged by a failed U-joint, this is the part.

What the pinion yoke does in a GM 9.5 14-bolt

The 9.5 in. semi-float shares the 14-bolt cover shape with the much larger 10.5 in. full-float axle, but it is a lighter-duty design with C-clip axles. Its pinion has 30 splines, and the yoke rides on them, clamped by the pinion nut against the front pinion bearing. Three jobs depend on it: transferring torque from the driveshaft into the ring and pinion, providing the smooth hub the pinion seal lip runs on, and holding the rear U-joint. This yoke takes a 1350 joint with 1.188 in. caps and a 3.625 in. snap ring span, outside snap ring, and Yukon specifies GM 3920486 straps to retain the caps.

Symptoms of a worn yoke

• Rear pinion seal leaking again shortly after replacement, from a groove the old seal wore into the yoke hub
• Clunk on takeoff or when shifting between drive and reverse, from a loose yoke on the splines
• Vibration that rises with speed after a U-joint has failed and hammered the ears
• Rust pitting on the seal surface on a truck or van that sat outside
• Visible spline twist or a pinion nut that will not hold torque

How to confirm the yoke is the problem

With the driveshaft off, clean the yoke hub and drag a fingernail across the seal path. If it catches, the yoke needs replacing, not just the seal. Then rock the yoke: play means the pinion nut has backed off or the pinion bearings are worn, and our pinion bearing noise guide explains what to listen for. Leak diagnosis is covered in our pinion seal leak guide. If the bearings are tired, replace the yoke as part of a rebuild with the 1979-97 GM 9.5 master overhaul kit, and consider new gears such as the GM 9.5 4.88 ring and pinion if you are re-gearing for bigger tires.

Fitment

Yukon's chart lists this yoke for the GM 9.5 in. rear with the 14-bolt cover in 1988-2000 Chevrolet and GMC C/K1500 and C/K2500, 1979-1986 C/K20, 1987-1991 R/V20 and R/V2500 Suburbans, 1992-1999 C/K1500 and C/K2500 Suburban, 1997-1999 Tahoe, 1992-1999 GMC Yukon, 1999 Silverado and Sierra 1500 and 2500, 1979-1996 G20/G30 vans, and 1996-1999 Express and Savana 1500/2500. Those same model lines were also built with other rear axles, so confirm what is under your truck before ordering. The 9.5 semi-float has a 14-bolt cover and C-clip retained axle shafts; it is not the 10.5 in. full-float 14-bolt, which uses the 1410 14-bolt full-float yoke. A 10-bolt cover means you have the 8.5 in., which takes the GM 8.5 forged 1350 yoke. Count the pinion splines (30) and check the cap span, or send us your year and VIN. More options are in axle hard parts.

Install notes

• Mark the driveshaft and yoke so the shaft goes back in the same phase.
• Check pinion rotating torque with an inch-pound wrench before removing the nut, and reassemble to the correct preload from the service manual. Never just crank the nut down tighter.
• Remove the old yoke with a holding tool and puller; hammering it off damages the bearings.
• Fit a new pinion seal with the new yoke and lube its lip.
• Use new straps and bolts on the 1350 joint and replace the joint if it feels notchy; a U-joint press kit helps.
• Top up with 75W-90 gear oil, adding friction modifier if the axle has a G80 or other limited slip, per the owner manual.

How do I tell a 9.5 semi-float from a 10.5 full-float 14-bolt?

Both have a 14-bolt cover. The full-float 10.5 has axle shaft flanges bolted to the outside of the hubs. The 9.5 semi-float uses C-clip axles with no bolted flange at the hub center.

What U-joint does this yoke take?

A 1350 series joint with 1.188 in. caps and a 3.625 in. snap ring span, outside snap ring, retained with GM 3920486 style straps.

Will it fit my 10-bolt?

No. The 10-bolt 8.5 in. uses its own yoke. This part is for the 9.5 in. 14-bolt semi-float rear.

Do I need a new pinion seal?

Yes. Always install a new pinion seal with a new yoke, since the old seal has worn to the old surface.

Do I need to reset pinion preload?

Yes. Measure rotating torque before removing the nut and restore the correct preload on reassembly following the service manual.