Yukon Gear Hardcore Locking Hub Set For Dana 60 / 30 Spline. 99-04 Ford

Owners of 1999-2004 Ford F-250 and F-350 Super Duty 4x4s with the Dana 60 front axle know the routine: the factory hubs stop working in AUTO, you live in LOCK, and then one side starts grinding or the dial cracks. For trucks that still run the 30-spline outer axle stubs, the Yukon Gear & Axle Hardcore locking hub set YHC70004 swaps both factory lockouts for all-steel manual hubs, so engaging the front axle comes down to a 1/3 turn of the dial.

What the locking hub does on a 30-spline Super Duty

These trucks use a unit bearing wheel hub bolted to the steering knuckle. The 30-spline outer stub passes through the bearing and is retained by a washer and snap ring, and the lockout bolts to the outer face. In LOCK, the Hardcore hub's coil spring drives a splined driver and coupler onto the stub and into the hub splines, tying the axle to the wheel. In FREE, the cam spacer pulls the driver back so the wheel spins on its bearing and the front driveline rests. The factory hub depends on an AUTO mechanism and, on later trucks, vacuum. This Yukon hub has no AUTO mode, which leaves less to fail. Yukon uses chromoly internals and all-steel construction and designs the hub to default to locked and stay engaged under high torque.

Symptoms worth checking

• No front pull in AUTO while LOCK still works
• One front wheel ratchets or grinds when the axle is loaded
• Truck pulls to one side in 4WD because only one hub is engaging
• Dial loose, cracked, or hard to turn between positions
• Grease thrown on the inside of the wheel from a failed hub seal or o-ring

How to confirm before you buy

Start with LOCK. If the front axle pulls with the factory dials locked, the transfer case and front differential are working and the hubs are your problem. Our Super Duty 1999-2004 auto hub guide walks through the AUTO failure, and the locking hubs not engaging guide covers spline wear. Lift the front end and check the stub and unit bearing for play. Yukon notes a worn spindle-to-axle bearing can stop a lockout from engaging and releasing properly.

Fitment

Yukon's application chart lists YHC70004 for 30-spline Dana 60 fronts on 1999-2004 Ford Super Duty. Count the splines on the outer stub before you order. If the axle has been upgraded to 35-spline stubs with aftermarket unit bearings, the YHC70002 35-spline Super Duty set is the right one. Pre-1998 Ford F-350 trucks with a 30-spline Dana 60 use the YHC70003 set. Some first-generation Super Duty trucks have a Dana 50 front axle, so read the axle tag. If you want a stock-style AUTO hub instead, we also carry the 1999-2004 Super Duty auto locking hub pair. Send us your year, VIN and spline count if you are unsure.

Install notes

• Work on level ground with the parking brake set and the transfer case in 2WD or neutral.
• Leave the factory washer and snap ring on the stub. Yukon requires them on every unit bearing install.
• This kit does not include the spring retainer used on older spindle-nut axles. The coil spring sits inside the outer hub instead. Make sure it compresses freely and does not touch the axle or snap ring.
• Grease the hub splines, axle, spacer, driver, coupler and cam spacer with high pressure grease, and lube the o-rings.
• Use a drop of Loctite 242 on each bezel bolt and stop at 22 in-lbs. Over-tightening can bind the hub.
• The selector arrow must line up with FREE or LOCK. Yukon says not to drive if it does not.

Replacing the Super Duty front hub seals at the same time helps keep water out. For gear work on this axle, see the Super Duty Dana 60 front master install kit.

How do I know if my Super Duty is 30 or 35 spline?

Remove a hub and count the outer stub splines. YHC70004 is for 30-spline stubs; 35-spline stubs with aftermarket unit bearings take YHC70002.

Is there an AUTO position?

No. These are manual FREE/LOCK hubs. You turn the bezel 1/3 turn to lock the front axle.

Why is there no spring retainer in the box?

Yukon's instructions note the retainer is not included in the YHC70004 kit. On a unit bearing the coil spring sits inside the outer hub.

Do I reuse the factory washer and snap ring?

Yes. Yukon says the OEM washer and snap ring are required for all unit bearing installs.

Will these fit a Super Duty with a Dana 50?

This set is listed for Dana 60 fronts only. Check the axle tag first, since some 1999-2004 Super Duty trucks use a Dana 50.

What if the hubs get submerged?

Yukon says to take them apart, clean and re-grease them every time they are submerged in water or mud.