Yukon Gear Positraction internals For 9.5in GM w/ 33 Spline Axles

If your Chevy or GMC truck, van or SUV with the 9.5 inch semi-float rear has started clunking when you get on and off the throttle, or the cover came off and showed chipped spider gears or a scored cross shaft, the Yukon YPKGM9.5-P-33 replaces the gear set inside the carrier without buying a whole new posi. It is the internal gear kit for a GM 9.5 that has the Eaton Positraction carrier and 33-spline axle shafts.

What is in the kit, and what it does in a GM 9.5

Yukon lists the contents as two side gears, four pinion gears, the cross pin shaft, the roll pin that retains it, and the spider gear thrust washers. In the carrier, the axle shafts slide into the side gears on their 33 splines and are held by C-clips. The four pinion gears ride on the cross shaft and let the side gears turn at different speeds when the truck corners. In a Positraction case, the side gears also push on the clutch packs, so a worn gear set lets the clutches lose preload and the posi gets lazy. Note what is not in the box: this kit has no clutch discs, steels or preload springs. If your clutches are glazed, plan on a clutch kit too, or replace the whole carrier.

Symptoms of worn 9.5 posi internals

• A clunk from the rear on throttle tip-in or when shifting from drive to reverse
• Clicking or grinding in slow, tight turns
• Metal glitter or chips on the cover magnet when you change the gear oil
• Axle shafts with excess end play once the C-clips are seated, from a worn cross shaft or thrust washers
• A posi that no longer pushes both tires because the gear wear has unloaded the clutches

How to confirm before buying

Drain the oil, pull the cover and look. Rock each axle shaft back and forth and watch the spider gears: lots of slop, broken teeth or a cross shaft with a stepped wear groove tells you the internals are done. Then make sure you have the right axle and carrier. The 9.5 is a semi-float 14-bolt-cover rear used in heavier half-ton and some three-quarter-ton trucks, vans and SUVs; it is not the full-float 10.5 inch 14-bolt. Our spider gear failure guide covers what to look for, and the GM 14-bolt problems guide helps separate the 9.5 semi-float from the 10.5.

Fitment

Yukon lists this kit for the GM 9.5 inch rear with Eaton Positraction and 33-spline axle shafts. Many 9.5 trucks left the factory with an open carrier or GM's automatic locker instead of a clutch posi, and those carriers do not use these internals, so confirm what is in your housing first. Yukon does not split this kit by year, and GM built the earlier 14-bolt-cover 9.5 and the later 2014-up 12-bolt-cover 9.5/9.76 with different carriers, so send us your year, VIN and a photo of the carrier if you are not sure. If the whole posi is tired, the Yukon Dura Grip 33-spline 9.5 posi is a complete carrier, and later 12-bolt-cover trucks use the 9.5/9.76 Truetrac 917A732. Browse the rest in our hard parts section.

Install notes

• The carrier stays in the housing for a spider gear swap on most posi designs, but you must pull the cross shaft, push in the axles and remove the C-clips before the gears can come out.
• On a clutch posi, the preload spring holds the side gears apart, so it needs to be compressed and removed carefully before the gears roll out. Note the order of every washer and clutch.
• Install new thrust washers behind every gear, use a new roll pin, and check axle end play after the C-clips go back in.
• If the carrier or pinion bearings are rough, this is the time for a GM 9.5 master overhaul kit.
• Refill with GL-5 gear oil plus limited slip friction modifier, since the clutch packs in an Eaton posi need it. Our friction modifier guide covers the amount.

Does this kit include clutch plates?

No. Yukon lists two side gears, four pinion gears, the cross pin shaft, roll pin and spider gear thrust washers. Clutches and springs are separate.

Will it fit an open or locker 9.5 carrier?

It is made for the GM 9.5 Eaton Positraction carrier. Open carriers and GM's automatic locker use different internals, so confirm your carrier type before ordering.

My axles are 30-spline. Is there a version for that?

This kit is the 33-spline version only. Count the splines on a shaft, or send us your year and VIN and we will check.

What gear oil should I use after the swap?

A GL-5 gear oil in the grade your owner's manual lists, plus limited slip friction modifier for the clutch packs in the posi.

Do I have to remove the carrier to replace the spider gears?

Usually not. You pull the cross shaft, push the axles in to remove the C-clips, remove the axles, then roll the gears out. Bearings and setup stay untouched unless you are replacing them.

What else should I replace while it is apart?

The cover gasket, any worn clutch pack, and the axle seals if they are weeping. Rough carrier or pinion bearings mean a full overhaul kit.