Yukon Gear 14T & GM 11.5in 30 Spline 38.2-42.2in Cut-To-Fit Axle Shaft 4340
A twisted or snapped rear axle shaft in a GM 10.5 inch 14-bolt or a GM 11.5 inch rear end usually shows up on a lifted truck with big tires, a locker, or a custom-width housing that no stock shaft fits. Yukon Gear & Axle part YA WGM14T-30-42 is a 4340 chromoly 30-spline full-float axle shaft made as a cut-to-fit blank for applications that measure between 38.2 and 42.2 inches. It is aimed at builders who need one shaft length that is not on the shelf, or who want one stronger shaft design that can be finished to either side of the housing.
Both of these are full-float housings. The weight of the truck rides on the hub bearings on the axle tube spindle, not on the shaft. The axle shaft only carries torque: its 30-spline inner end slides into the differential side gear and its flange bolts to the wheel hub. That is why a full-float shaft can be pulled with the wheel still on the truck. The trade-off is that every bit of torque from the gears, locker and tires twists the shaft, so a shaft that has been overloaded twists along its length or breaks near the splines. Yukon makes this shaft from 4340 chromoly with cold roll formed splines and induction heat treating, which compresses the grain of the metal in the splines rather than cutting it away.
Pull the shaft: remove the flange bolts at the hub and slide it out. Check the splines, the flange and the shaft for twist by rolling it on a flat surface. Then measure correctly. Yukon measures full-float shafts from the end of the splines to the front surface of the mounting flange; that is the number that must fall in the 38.2 to 42.2 inch range. If the splines are damaged, inspect the side gears and locker or spider gears too, since a broken shaft often takes the side gear with it. Our GM 14-bolt rear axle problems guide covers what else to check.
Yukon lists this shaft for the GM 10.5 inch 14-bolt truck and the GM 11.5 inch, both with 30-spline axles. It is not a direct-fit length for one specific truck; it is sized for builds where the measured length lands between 38.2 and 42.2 inches, such as narrowed or widened housings and swaps. Finishing a cut-to-fit shaft to length is shop work, so confirm the final length, the flange bolt pattern of your hubs and the spline count with your driveline or machine shop before you buy. If your truck is stock, a fixed-length shaft such as the 4340 chromoly 14-bolt axle or the 1541H alloy 14-bolt axle may bolt in. If you are not sure which rear end you have, our 14-bolt vs AAM 11.5 guide explains how to tell, or send us the year, VIN and your measurement.
Many builders who break shafts are also running a locker. If you are building the whole axle, the Grizzly Locker for 30-spline 14-bolt axles pairs with this shaft, and our chromoly vs stock axle shaft guide covers when the upgrade makes sense.
| Brand | Yukon Gear & Axle |
| Part number | YA WGM14T-30-42 |
| Fits | Yukon Gear 14T & GM 11.5in 30 Spline 38.2-42.2in Cut-To-Fit Axle Shaft 4340 |
| 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 measures full-float axles from the end of the splines to the front surface of the mounting flange. That length needs to fall between 38.2 and 42.2 inches.
Yukon lists it for both, with 30-spline axles. Confirm your rear end, spline count and hub flange pattern before ordering.
The listing is one axle shaft. Order two if you are replacing both sides.
Yukon uses 4340 chromoly with cold roll formed splines and induction heat treating for strength. It makes sense for trucks with big tires, lockers or high torque that have twisted or broken stock shafts.
No. On a full-float axle the shaft unbolts from the hub and slides out with the wheel still on, because the hub bearings carry the truck's weight. You will lose a little gear oil, so top it off afterward.
