Yukon Gear Hardcore Locking Hub Set For GM 8.5in Front & Dana 44 / 19 Spline
If your Chevy or GMC K-truck, Blazer or Jimmy has the GM 8.5 inch 10-bolt front axle, or you are building an early 1966-1977 Ford Bronco with its Dana 44, worn manual hubs are a common reason the front end will not grab when you shift into 4WD. Yukon Gear & Axle part YHC70007 is a pair of Hardcore locking hubs made for these 19-spline outer stubs, with all-steel construction and chromoly internals. It is also the set Yukon points to for custom Dana 44 builds that use 19-spline stubs.
The wheel hub rides on the spindle bearings, and the 19-spline outer stub passes through the spindle into the hub center. The locking hub is what joins them. On FREE the stub and front differential sit still while the wheel rolls, so the front driveline is not turning in 2WD. On LOCK, the driver and coupler mesh with the stub and the wheel hub and the front axle can pull. The Yukon Hardcore design engages with a 1/3 turn of the low-profile bezel and defaults to the locked position. What sets YHC70007 apart from Yukon's other 19-spline set is spacing: the kit ships with 2.5 mm, 4.0 mm and 6.0 mm spacers, because GM 10-bolt, early Bronco and custom hubs do not all have the same depth.
With both front tires off the ground and the transfer case in neutral, set both hubs to LOCK and turn a tire: the driveshaft should move. Then set FREE, spin the tire and watch the stub; it should not turn. Check the stub for up-and-down and side play first, since a worn spindle-to-axle bearing keeps any hub from working right. Our locking hubs not engaging guide walks through the full checklist.
Yukon's application guide lists YHC70007 for 1979-and-up GM 8.5 inch front axles and 1966-1977 Ford Bronco Dana 44 fronts, plus many custom Dana 44 setups with 19-spline stubs, and the product page also describes it as fitting 1979-and-up GM Dana 44. It does not work with Stage-8 lock nuts. If you would rather run the front axle full time, Yukon also makes a Hardcore drive flange kit for 19-spline stubs. Because GM used both the 8.5 10-bolt and the Dana 44 on K-series trucks in this era, count the stub splines and confirm your axle before you order. A 1978-and-older GM Dana 44 or a 1978-1992 Ford takes the YHC70006 Hardcore set. If you are unsure, send us the year, VIN and spline count.
If the spindle is scored or loose, the Dana 44 and GM 8.5 front spindle is the matching replacement. A noisy front 10-bolt is a good time for the GM 8.5 front master overhaul kit, and the manual locking hub buyers guide compares other hub options.
| Brand | Yukon Gear & Axle |
| Part number | YHC70007 |
| Fits | Yukon Gear Hardcore Locking Hub Set For GM 8.5in Front & Dana 44 / 19 Spline |
| Type | Differential Install Kits |
| 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 for 1979-and-up GM 8.5 inch front axles with 19-spline stubs, which is the 10-bolt front used on many K-series half-tons and Blazers. Count the stub splines and confirm the axle before ordering.
It includes 2.5 mm, 4.0 mm and 6.0 mm spacers so it can fit GM 8.5, early Bronco and custom hubs of different depths. Yukon has you start with the thickest and step down until the hub snap ring installs.
Yes. Yukon lists YHC70007 for the 1966-1977 Bronco Dana 44 front.
Yukon warns that a spacer that is too thin can damage the hub assembly or make the hub lock itself while set to FREE. Follow the snap ring fit test.
Check the stub axle for play and the front U-joints and differential first. A worn spindle-to-axle bearing or a broken axle shaft will act like a bad hub, and a new hub will not fix it.
