Yukon Gear Right Hand Inner 4340 Chrome Moly Rplcmnt Axle Shaft For Dana 44 / 75-79 Ford F250

Snapped a front shaft on your 1975-1979 Ford F-250 4x4, or found the passenger-side inner axle twisted, chewed at the splines or pitted where the seal rides? This is the Yukon Gear and Axle YA W38814 right-hand inner front axle for the Dana 44 under those trucks. It is made from 4340 chromoly with cold-rolled 30-spline teeth and induction heat treating, so it is a stronger shaft than the factory carbon-steel part it replaces, which matters on a truck that now runs bigger tires or a locker.

What the right inner axle does in a Dana 44 front

On a solid-axle Dana 44 front, each side uses a two-piece shaft. The inner shaft slides through the axle tube and engages the side gear in the differential carrier with its 30 splines. At the other end it ends in a yoke for the steering U-joint, which links it to the short outer stub that drives the hub. Yukon's application data lists this shaft for the reverse-rotation (high-pinion) Dana 44 front used in these Ford trucks. When you turn the wheel in four-wheel drive, the U-joint lets the outer stub swing with the knuckle while the inner shaft keeps driving straight out of the carrier.

Symptoms of a failed or worn inner axle

• A bang followed by grinding or clicking from the front end, and the truck no longer pulls with the front wheels in 4WD
• Gear oil weeping from the tube or knuckle area because a worn seal surface on the shaft lets oil past
• Clicking or popping when turning in 4WD, often from the U-joint at the end of the shaft
• A clunk when engaging four-wheel drive with the hubs locked
• Twisted or rounded splines found during a carrier or ring and pinion job

How to confirm before ordering

Lock the hubs, raise the front end and turn one tire by hand while watching the other side and the driveshaft. A broken inner shaft lets one side spin freely with nothing moving at the carrier. With the shaft out, check the splines for twist, measure the length (this one is 34.75 inches) and count the splines. Inspect the U-joint caps for rust tracks or a notchy feel. If the carrier is worn too, our hard parts department carries Dana 44 gears, lockers and bearings.

Fitment

Listed for 1975-1979 Ford F-250 4WD with the Dana 44 front axle: front inner shaft, right-hand (passenger) side, 30 spline, 34.75 inches long, built for a 5-760X series U-joint. The Dana 44 shows up under many trucks with different shaft lengths, spline counts and carrier offsets, so do not assume another vehicle fits. Compare length and spline count with your old shaft, check the axle tag if it is still there, or send us your year and VIN to confirm. The 1969-1979 F-150 has a complete chromoly front axle kit of its own if you are building that truck.

Install notes

• Remove the locking hub, spindle nuts and spindle to get the inner and outer shaft out as one assembly through the knuckle.
• Press the old joint out of the yokes with a U-joint C-frame press or the adapters in a ball joint and U-joint press kit. Do not hammer the yoke ears.
• Use a new 5-760X joint (1310 series, 1.188 inch caps, inside snap rings) rather than reusing the old one, and check that the outer stub is not cracked or worn.
• Replace the inner axle seals if your axle has them and slide the shaft in carefully so the splines do not cut a new seal.
• Use new spindle bearings and seals, refill the differential with 75W-90 gear oil, and check the level at the fill plug.
• Building for traction on a 30-spline carrier? A Dura Grip spider set or a Dana 44 steel spool uses the same spline count.

Which side is this axle for?

It is the right-hand (passenger side) front inner shaft. It measures 34.75 inches and has 30 splines at the carrier end.

What U-joint does it take?

It is built for the 5-760X series joint, a 1310-size joint with 1.188 inch caps and inside snap rings. Install a new joint with the new shaft.

Will it fit a Dana 44 from another truck?

Only if the length, spline count and yoke match. It is listed for the 1975-1979 Ford F-250 4WD Dana 44 front. Measure your old shaft or send us your year and VIN.

Why choose 4340 chromoly over a stock replacement?

Yukon makes this shaft from 4340 chromoly with cold-rolled splines and induction heat treating. It handles bigger tires and lockers better than a stock carbon-steel shaft.

What gear oil goes back in the front differential?

75W-90 gear oil is the usual fill for a Dana 44 front. Fill to the bottom of the fill hole after the shafts are back in.