Yukon Gear 4340 Chrome Moly Rear Axle For GM 11.5in 14 Bolt Truck 30 Spline
Twisted a rear shaft in a 3/4-ton or 1-ton GM truck, van or Suburban, or building a full-float rear for big tires and a locker? Yukon Gear & Axle part YA WGM14T-30-38 is a 4340 chromoly 30-spline rear axle shaft for the GM 11.5 inch rear and the 1999-and-up GM 10.5 inch 14-bolt. It is Yukon's cut-to-length design for applications that measure from 34.8 to 38.8 inches, which makes it the shorter of Yukon's two 30-spline chromoly shafts for these axles. Price is for one shaft.
In a full-float rear, the wheel hub rides on its own pair of bearings on the axle tube, so the truck's weight never rests on the shaft. The shaft is a torque tube: its 30-spline inner end engages the differential side gear and its flange bolts to the hub. Because it only twists, an overloaded shaft fails by twisting along its length or by shearing near the splines. The two sides of a 14-bolt are different lengths, which is why measuring each side matters. Yukon builds this shaft from high-tensile 4340 chromoly with cold roll formed splines and induction heat treating, made to resist twist better than a stock shaft when the truck is towing heavy or turning tall tires with a locker.
A full-float shaft is easy to inspect: remove the flange bolts at the hub and slide the shaft out with the wheel on the ground. Roll it across a flat floor to check for a bend, look down the splines for twist, and check the flange for cracks. Measure your old shaft from the spline end to the front face of the mounting flange; for this part your number must land between 34.8 and 38.8 inches. Longer measurements belong to the 38.2-42.2 inch cut-to-fit 14-bolt shaft. If a shaft broke, check the side gears and spider gears too. Our GM 14-bolt rear axle problems guide covers the rest of the axle.
Yukon lists this shaft for the GM 10.5 inch 14-bolt truck axle from 1999 on and for the GM 11.5 inch, both with 30-spline axles. Yukon's vehicle list includes 1999-2000 C/K 2500 and 3500, 1999-2004 Silverado and Sierra 2500, 2001-2012 Silverado 2500 HD, 2001-2010 Sierra 2500 HD, 2001-2006 Silverado and Sierra 3500, 2007-2010 Silverado and Sierra 3500 HD, 1999-2013 Express and Savana 2500 and 3500, 2000-2013 Suburban 2500, Yukon XL 2500 and the 2002-2006 Avalanche 2500. Because it is a cut-to-length shaft, final length is set by your measurement, so confirm the length, side, hub flange and spline count with your driveline shop. If you are not sure whether you have the GM 10.5 14-bolt or the AAM 11.5, our 14-bolt vs 11.5 guide shows how to tell, or send us your year and VIN. Yukon also makes a separate 30-spline shaft listed for the GM 10.5 only, the 4340 chromoly 10.5 14-bolt axle.
For when chromoly makes sense, read our chromoly vs stock axle shaft guide.
| Brand | Yukon Gear & Axle |
| Part number | YA WGM14T-30-38 |
| Fits | Yukon Gear 4340 Chrome Moly Rear Axle For GM 11.5in 14 Bolt Truck 30 Spline |
| Type | Axles |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yukon lists it as a cut-to-length design for 34.8 to 38.8 inch applications. Measure from the end of the splines to the front face of the mounting flange. Longer shafts need the 38.2-42.2 inch version.
Yukon lists it for the GM 11.5 inch and the 1999-and-up GM 10.5 inch 14-bolt truck axle, both with 30-spline axles.
One axle shaft. The two sides of a 14-bolt are different lengths, so measure each side and order the correct shaft for each.
No. Unbolt the flange at the hub and slide the shaft out with the wheel on the ground. The hub bearings carry the truck's weight, not the shaft.
Top off with 75W-90 or 75W-140 gear oil. Add friction modifier only if the axle has a clutch-type limited slip that calls for it.
