Yukon Gear Master Overhaul Kit For 2010 & Down GM and Dodge 11.5in Diff

If your 2001-2010 Silverado or Sierra 2500HD/3500, or a 2003-2010 Ram 2500 or 3500, has a rear end that whines on the highway, rumbles under a trailer or leaks gear oil at the yoke, the bearings in the American Axle 11.5 in. ring and pinion are the usual cause. The Yukon Gear & Axle YK GM11.5 master overhaul kit is the early-design parts set for that axle: new Timken carrier and pinion bearings with their races, a pinion seal, a full shim kit and the small parts needed to set the gears up again. It is new and built for 2010-and-earlier 11.5 in. AAM axles only.

What a master overhaul kit does in the AAM 11.5

The 11.5 in. AAM is a full-floating axle, so the axle shafts do not carry the truck's weight; the hubs do. What the center section carries is torque. The pinion runs on two tapered roller bearings and the differential carrier runs on two more, and those four bearings hold the ring and pinion at the exact depth, preload and backlash the gears were lapped for. Once a bearing pits or the preload loosens, the gear mesh walks out of position and the teeth start to sing. Replacing every bearing and race at once, along with a fresh seal and new shims, lets you put the gears back where they belong instead of chasing one noise at a time.

Published contents for the YK GM11.5 are carrier bearings and races, pinion bearings and races, a pinion seal, a complete shim kit, a pinion nut, thread locker, marking compound with a brush, and silicone for the cover.

Symptoms of a worn 11.5 center section

• A steady whine or howl at one road speed that changes on throttle or coast.
• A low growl that gets louder with a load in the bed or on the hitch.
• Gear oil seeping from the pinion seal and wetting the bottom of the housing.
• In-and-out play at the pinion yoke, or a clunk when the truck goes from Drive to Reverse.
• Shiny metal paste on the cover or drain plug at a gear oil change.

How to confirm before you order

Separate axle noise from everything else first. Full-floating hub bearings, tires with cupped tread and a worn driveshaft support bearing can all sound like a bad pinion bearing. With the rear wheels off the ground and the transmission in neutral, spin the pinion by hand: roughness or a gritty, notchy feel points to the pinion bearings. Rock the yoke up and down and in and out; any movement means preload is gone. Drain the oil and look at the cover. Chipped teeth, a scuffed contact pattern or a broken tooth mean the gears need replacing too, and a gear swap is the time to add the 11.5 in. 4.10 ring and pinion set.

Fitment

This kit is listed for 2010-and-down GM and Chrysler 11.5 in. AAM axles, including the 2001-2010 Silverado and Sierra 2500HD, 2001-2006 Silverado and Sierra 3500, the 2007 Classic 3500 trucks, 2007-2010 Silverado and Sierra 3500HD, and 2003-2010 Ram 2500 and 3500. The important detail is the pinion bearing. In mid-2011 AAM changed the rear pinion race from a 4.125 in. outside diameter to 4.375 in., and this kit is the 4.125 in. design. A 2011 truck can have either, so measure the race or read the axle tag. Later axles take the Yukon YK GM11.5-B for 2011-up. If you want a Koyo-bearing alternative for the same early axle, see the USA Standard ZK GM11.5. Not sure which you have? Send us your year, model and VIN, or browse the rebuild kits collection.

Install notes

• Before teardown, paint a few ring gear teeth with the supplied marking compound and record the pattern and backlash. That gives you a baseline.
• Keep the carrier bearing caps in their original positions and orientation; they are machined with the housing.
• Start with the original pinion depth shim, then confirm with a pattern check after the new bearings are in.
• Bring pinion preload up gradually while checking rotating torque with an inch-pound torque wrench. Overshooting the spec means starting over.
• Set carrier preload and backlash with the shim kit, re-check the pattern, then seal the cover with the supplied silicone.
• Refill with the gear oil grade and amount in your owner's manual, typically 75W-90, or a 75W-140 synthetic for heavy towing.

While the axle is apart, a Yukon Hardcore 11.5 diff cover adds protection, and Ram owners can do the hub side at the same time with the Yukon 11.5 wheel bearing and seal kit.

Will this kit fit my 2011 Silverado 2500HD?

Maybe. AAM switched the rear pinion race from 4.125 in. to 4.375 in. OD in mid-2011. This YK GM11.5 is the 4.125 in. early design. Measure the race or check the axle build date, and use the YK GM11.5-B if your axle is the later design.

Can I reuse my ring and pinion with this kit?

Yes, as long as the gear teeth are not chipped, pitted or scored. The kit is bearings, races, seal and shims, so it is built for re-setting your existing gears or installing a new set.

Does the kit include a new ring and pinion or a carrier?

No. It contains bearings and races, a pinion seal, shim kit, pinion nut, thread locker, marking compound with brush and silicone. Gears, carriers and lockers are sold separately.

What gear oil should go back in?

Use the grade and capacity listed in your owner's manual for the 11.5 in. axle. Most of these trucks take 75W-90, and many owners who tow use a 75W-140 synthetic. A limited-slip unit may need friction modifier.

Can I install it myself?

Only if you have the tools to measure pinion depth, preload and backlash: a dial indicator, an inch-pound torque wrench, a bearing puller and a press. Without them, have a driveline shop set it up so the gears stay quiet.