Yukon Gear Master Overhaul Kit For Dana 80 Diff (4.375in OD Only On 98+ Fords)

The Dana 80 under a dually Ford F-350 Super Duty, an early F-450 pickup or an E-350 one-ton van spends its life loaded: campers, gooseneck trailers, ambulance boxes and shuttle-bus bodies. When that axle starts howling on the highway, rumbling as the load comes on, or seeping oil around the pinion, the Yukon Gear & Axle YK D80-B master overhaul kit is the bearing-and-seal package to rebuild it. It is a new kit, part number YK D80-B, built specifically for the Ford version of the Dana 80 that uses the larger 4.375 in. outside-diameter pinion bearing race.

What this kit does in a Dana 80 rear axle

The Dana 80 is a full-floating, 8-lug axle with a 12-bolt ring gear and a 10-bolt cover, offered with 35- or 37-spline axle shafts. The axle shafts only transmit torque; the truck's weight rides on the hub bearings, so the carrier and pinion bearings are left to handle gear loads. Those loads are large. As the pinion bearings wear, pinion depth and preload drift, the ring and pinion contact pattern walks off the center of the teeth, and the gear set starts to sing. Left alone, a loose pinion chews up the gear teeth and turns a bearing job into a gear job. Yukon's kit replaces the wear parts that hold the gears in position: Timken carrier bearings and races, Timken pinion bearings and races, a pinion seal, a complete shim kit, a pinion nut, oil baffles and slingers where the application uses them, thread locking compound, marking compound with a brush, and a cover gasket.

Symptoms of a worn Dana 80

• A steady whine or howl at cruising speed that changes when you lift off the throttle.
• A low growl that gets louder with a trailer or a full bed, typical of a pitted pinion bearing.
• Clunk on take-off or when shifting into Drive, with free play at the pinion yoke.
• Gear oil wetting the pinion seal area or dripping from the yoke.
• Glitter or metal paste in the oil and on the drain plug or cover.

How to confirm before you buy

Lift the axle and block the truck safely. With the driveshaft unbolted, rotate the pinion by hand and feel for roughness, then rock the yoke up and down and in and out; any end play means the pinion bearings or preload are gone. Drain the oil into a clean pan and look at it in good light. Pull the cover and paint a few ring gear teeth with marking compound to read the pattern. Healthy teeth with a worn pattern mean this kit is the fix. Chipped, spalled or blued teeth mean you need gears as well. Before blaming the center section, check the hub bearings and hub seals on the full-floating hubs, because a dry hub bearing can sound remarkably similar.

Fitment

The YK D80-B fits only the Dana 80 with the 4.375 in. OD pinion bearing race. Our listing describes it for 1998-and-newer Fords; published Yukon application data lists the 1999-2016 Ford F-350 Super Duty dual rear wheel, the 1999-2005 F-450 Super Duty, the 1999-2010 E-350 one-ton and the 2000-2005 E-450. Dana 80s with the smaller 4.125 in. pinion race take a different kit, such as the USA Standard ZK D80-A for 4.125 in. OD. If you cannot confirm the race size, measure the old outer race or send us your year, model and VIN before ordering. A value-priced alternative for the same 4.375 in. axle is the USA Standard Dana 80 master overhaul kit, and the full lineup is in our rebuild kits collection.

Install notes

• Mark the carrier bearing caps before removal; they are machined with the housing and must go back in the same position and orientation.
• The Dana 80 carrier is held in with preload, so plan on a case spreader such as the Dana 30-80 housing spreader to remove and install it without damaging the housing.
• Record the original pinion depth shim as a starting point, then confirm depth and backlash with the marking compound and the kit shims.
• Set pinion bearing preload and carrier preload to the figures in the factory service manual, and torque the pinion nut and ring gear bolts to spec with thread locker on the bolts.
• Fill with the gear oil grade and capacity your owner's manual lists, and add friction modifier only if the axle has a limited-slip carrier that calls for it.

If the pattern check shows damaged teeth, replace the gears during the same teardown; the Dana 80 5.38 ring and pinion set is one option for a deep-geared work truck.

Which trucks does the Yukon YK D80-B fit?

It fits the Ford Dana 80 rear axle with the 4.375 in. OD pinion bearing race. Published applications are the 1999-2016 F-350 Super Duty dual rear wheel, 1999-2005 F-450 Super Duty, 1999-2010 E-350 one-ton and 2000-2005 E-450. Send us your VIN if you are unsure.

How do I tell a 4.375 in. Dana 80 from a 4.125 in. Dana 80?

The difference is the outside diameter of the pinion head bearing race in the housing. Measure the old race once the pinion is out, or check the axle tag and VIN with us before you order. The 4.125 in. axles need a different kit.

Does this kit include a ring and pinion?

No. It is a bearing, seal and shim package for rebuilding the axle with your current gears or a new gear set. If the teeth are chipped or pitted, order a ring and pinion along with it.

What comes in the kit?

Timken carrier bearings and races, Timken pinion bearings and races, a pinion seal, a complete shim kit, a pinion nut, oil baffles and slingers where applicable, thread locking compound, marking compound with a brush, and a cover gasket.

Can I install it without special tools?

You will need a bearing puller and press, a dial indicator for backlash, an inch-pound torque wrench for preload and a case spreader to remove and install the Dana 80 carrier. Without those, a driveline shop should set it up.