Yukon Gear Hardcore Locking Hub Set For Dana 44 / GM & Ford 1/2 & 3/4 Ton / 19 Spline

Owners of 1969-1978 Chevy and GMC K-series trucks, K5 Blazers and Suburbans, and 1978-1992 Ford F-150, F-250 and Bronco 4x4s with a 19-spline Dana 44 front axle usually start shopping for hubs for one of three reasons: the old hubs pop out of lock under load, the dial will not turn, or the front axle simply stops pulling. Yukon Gear & Axle part YHC70006 is a Hardcore locking hub set that replaces both front hubs on these axles with all-steel units and chromoly internals.

What the locking hubs do on a 19-spline Dana 44

On these trucks the wheel hub spins on tapered bearings on the spindle, and the outer axle stub comes through the spindle into the middle of the hub. The 19-spline stub is the small spline count used on the older Dana 44 fronts. The locking hub sits between the stub and the wheel hub. Set to FREE, the wheel rolls on its bearings and the front axle shafts, front differential and front driveshaft stay put. Set to LOCK, a splined driver and coupler tie the stub to the wheel hub so the front axle can drive. Yukon builds this hub so a 1/3 turn of the low-profile steel bezel moves it from disengaged to engaged, says it defaults to the locked position, and says it will not disengage under high torque. The set includes 2.5 mm spacers.

Symptoms that point to the front hubs

• Transfer case in 4WD but the front tires do not pull, on one side or both
• Grinding, clicking or ratcheting from one front wheel when the truck is loaded in 4WD
• A selector that is stiff, will not stay centered on FREE or LOCK, or spins with no effect
• Front driveshaft still turning in 2WD with both hubs on FREE
• Water, rust or mud inside the hub after a creek crossing

How to confirm the hubs are bad before you buy

Lift both front tires off the ground. Dial both hubs to LOCK and turn a tire by hand: the driveshaft should turn. Dial them to FREE and spin the tire again, then look behind the wheel; the stub axle should stand still. Before blaming the hubs, grab the stub and check for play up and down and side to side. Yukon warns that a worn spindle-to-axle bearing can stop any lockout from engaging and releasing properly, so that bearing has to be right first. Our locking hubs not engaging guide covers vacuum, bearing and shaft causes, and the manual locking hub buyers guide compares hub options for Dana 44 and Dana 60 axles.

Fitment

Yukon lists YHC70006 for 1978-and-older GM Dana 44 fronts (including the 1969-1974 Blazer, 1975-1978 K5 Blazer and 1978 K10, K20, K15 and K25 trucks and Suburbans) and for 1978-1992 Ford Dana 44 fronts: the 1978-1979 F-150, F-250 and Bronco straight axle and the 1980-1992 Bronco and F-150 and 1980-1990 F-250 twin-traction-beam Dana 44. It also fits trucks running the Yukon YA WU-01 and WU-02 Spin Free conversions. It does not work with Stage-8 lock nuts. If you want the front axle locked in full time instead, Yukon makes a Hardcore drive flange kit for 19-spline Dana 44 stubs. Count 19 splines on the outer stub before you order. A 1979-and-up GM 8.5 front or a 1966-1977 Bronco uses the YHC70007 Hardcore set instead, and a 30-spline Dana 30 or Dana 44 stub needs Yukon's 30-spline YHC70005 set. If your truck has had an axle swap or you are not sure, send us the year, VIN and spline count and we will check it.

Install notes

• Park level, set the parking brake and put the transfer case in 2WD or neutral before taking the old lockouts off.
• With the old hubs out you can see the stub and spindle nuts. Repack the wheel bearings now if they need it and set preload correctly; bearing setup affects how the hub works.
• Clean and deburr the wheel hub splines. Damaged splines in the wheel hub cause poor lockout function and the hub should be replaced.
• Grease the hub spline, stub, spacer, driver, coupler and cam spacer with high pressure grease as you assemble.
• Put one drop of Loctite 242 on each 10-24 bezel bolt and tighten to 22 in-lbs only. Over-tightening can bind the hub.
• Re-check LOCK and FREE with the wheels in the air before you drive.

For a Ford TTB truck with a worn spindle, the Dana 44 Ford F-150 5-hole spindle is listed in our catalog. If the front differential is whining or has been run low on oil, pair the hubs with the 19-spline Dana 44 master overhaul kit. TTB owners can also read our Ford TTB front axle problems guide.

Does YHC70006 fit a 1986 Ford F-150 or Bronco?

Yes, Yukon lists it for the 1980-1992 F-150 and Bronco with the Dana 44 twin-traction-beam front axle, as long as the outer stubs are 19 spline. Count the splines to be sure.

What is the difference between YHC70006 and YHC70007?

Both are 19-spline Hardcore sets. YHC70006 covers 1978-and-older GM Dana 44 and 1978-1992 Ford fronts and comes with 2.5 mm spacers. YHC70007 covers 1979-and-up GM 8.5 fronts and 1966-1977 Bronco Dana 44, and includes three spacer sizes.

Is this one hub or a pair?

It is a set with one hub for each front wheel.

Will it work with my Stage-8 lock nuts?

No. Yukon states this set does not work with Stage-8 spindle lock nuts, so plan on the standard nut setup.

What grease should I use, and do I service them after water crossings?

Use high pressure grease on the splines and internal parts during assembly. Yukon says the hubs must be taken apart, cleaned and re-greased each time they are submerged in water or mud.