Yukon Gear Rear Axle For GM 11.5in (00+) w/ A Length Of 35.94in and 30 Splines

Snapped or twisted a rear shaft in a 2001-2010 Silverado or Sierra 2500HD or 3500? Yukon YA G12471486 is a new replacement full-floating rear axle shaft for the GM AAM 11.5-inch rear: 30 splines, an 8-lug drive flange and an overall length of 35.94 inches. It is the shaft for the 2010-and-earlier version of the 11.5, the axle GM put under its heavy-duty pickups when it retired the 10.5 14-bolt.

What the axle shaft does in a GM 11.5

The 11.5 is a full-floater. Each rear hub rides on its own pair of tapered bearings on a spindle that is part of the housing, so the truck's weight and the trailer's tongue weight sit on the housing, not on the shafts. The shaft's only job is to transmit torque: its splines engage the side gear in the carrier and its flange bolts to the outside of the hub. That is why a broken shaft on an 11.5 usually does not let a wheel leave the truck, and also why these shafts can be pulled in minutes without opening the differential. Diesel torque, heavy trailers and wheel hop on wet ramps are what twist them.

Symptoms of a damaged shaft

• The truck will not move with one rear wheel on the ground and the driveshaft turning, typical of a snapped shaft or stripped splines in an open or worn limited-slip carrier.
• A heavy clunk when shifting into drive or reverse that gets worse under load.
• Gear oil seeping around the axle flange and down the wheel, from a failed flange gasket or a flange that is no longer flat.
• A flange that will not seat evenly against the hub, which points to a bent shaft.

A shaft failure does not set its own trouble code. Hub bearing growl and gear whine can sound similar, so confirm before ordering.

How to confirm it

Remove the flange bolts, break the flange loose and slide the shaft out. Look for twisted or rounded splines, a cracked flange, or a visible spiral in the shaft body. Roll it on a flat bench to spot a bend. While it is out, spin the hub by hand; roughness there is a hub bearing problem, not a shaft problem. Our AAM 11.5 problems and rebuild cost guide covers the bearing and gear failures that often get blamed on shafts, and full-floating vs semi-floating axles explains why this design behaves the way it does.

Fitment

The listing title reads "00+", but Yukon's fitment table for this part starts in 2001 and covers: 2001-2004 Chevrolet Silverado 2500 and GMC Sierra 2500, 2001-2010 Silverado and Sierra 2500HD, 2001-2006 Silverado and Sierra 3500, 2007 Silverado 3500 Classic, Sierra 2500HD Classic and Sierra 3500 Classic, and 2007-2010 Silverado 3500HD, in both 2WD and 4WD. Yukon describes the axle as GM 11.5, 2010 and down. The 2011-and-later GM 11.5 uses a longer 37.25-inch shaft, so this part will not fit those trucks. Ram trucks with the 11.5 are not on this part's list. Measure your old shaft from the spline end to the face of the flange and count the splines before you order, and send us your year and VIN if your truck is a dually or has had the rear axle swapped.

Install notes

• Clean both mating faces of the flange and hub completely and use a new flange gasket or sealer as the factory did. Torque the flange bolts to the service manual figure in a cross pattern.
• If the hub was leaking oil, replace the hub seals and check bearing adjustment while the shaft is out. The Yukon GM 11.5 axle bearing and seal kit covers that job.
• Top off with 75W-90 or 75W-140 gear oil. Metal on the magnet or chipped side gear splines means the carrier needs attention too; the Yukon master overhaul kit for 2010 and earlier 11.5 matches this axle generation.
• Broke a shaft towing? Consider the Yukon 4340 chromoly 30-spline shaft as the stronger option. If an open carrier left you stuck with one wheel spinning, the Yukon Dura Grip 30-spline 11.5 limited slip uses the same spline count as this shaft.

Does this fit my 2012 Silverado 2500HD?

No. Yukon lists this 35.94-inch shaft for the GM 11.5 through 2010. The 2011-and-later GM 11.5 uses a 37.25-inch shaft.

Will it fit a Ram 2500 or 3500 with the AAM 11.5?

Ram trucks are not in Yukon's fitment list for this part. Ram 11.5 shafts are a different part number; measure yours and contact us with the VIN.

Do I have to open the differential to install it?

No. On a full-floating axle the shaft comes out through the hub after you remove the flange bolts. You only open the cover if the carrier or side gear is damaged.

Is one shaft enough, or should I replace both sides?

Replace the one that failed, then pull and inspect the other. If its splines are twisted or the flange is distorted, it is close to failing too.

What gear oil goes back in?

75W-90 or 75W-140 gear oil. If the truck has a clutch-type limited slip, follow the friction modifier recommendation for that carrier.