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The Dana 70 is the axle that sits between the Dana 60 and the Dana 80 in heavy-duty trucks and vans. It has a ring gear of about 10.5 inches, a 10-bolt cover and, in almost every truck, full-float hubs. What kills them is boring: tired pinion bearings, hub seals left leaking until the brakes are soaked, hub bearings adjusted by guesswork, worn Powr-Lok clutches, and regears set up without a dial indicator.
Which Vehicles Have a Dana 70
- Dodge Ram 2500 and 3500, 1994-2002. The heavy-duty 2500 and many 3500s, especially with the Cummins or V10, ran a Dana 70 rear. Many 3500s got a Dana 80 instead, so check the tag.
- Ford F-250, F-350 and E-series vans. Heavy-duty Fords used the Dana 70 from the late 1960s until the Sterling 10.25 took over in the mid-1980s. Some heavier E-350 vans kept a 70-U longer.
- Older GM 1-tons. Some late-1960s and early-1970s GM 1-ton trucks used a Dana 70 before the corporate 14-bolt became standard. A 14-bolt cover means it is not a 70; see our GM 14-bolt guide.
No tag? Count the cover bolts. The 70 has 10, like the Dana 60, but the center section is visibly larger and the ring gear is around 10.5 inches against roughly 9.75 on a 60.
Dana 70 vs 70HD vs 70-U
The plain Dana 70 is the original design. The 70HD uses beefier axle shafts and bearings, and many of them run 35-spline shafts. The 70-U is the later version found in many 1980s and 1990s Dodge trucks and Ford vans. Its pinion bearings and some gear sets do not cross to an early 70, so kits are sold by version, like the Yukon master overhaul kit for the Dana 70-U ($544.46).
Semi Float vs Full Float, 32 vs 35 Spline
A few older 3/4-ton trucks got a semi-float Dana 70, where the axle shaft carries the truck's weight and the wheel bearing rides on the shaft. Almost every Dana 70 you will see is a full floater. The hub rides on two tapered bearings on a spindle, the shaft only turns the wheel, and if a shaft breaks the wheel stays on.
Most Dana 70 shafts are 32 spline; some heavy-duty versions are 35 spline. Pull the flange bolts, slide a shaft out and count before ordering axles, spider gears or a locker. A 35-spline open carrier takes the Yukon 35-spline open spider gear kit for the Dana 70 and 80 ($278.34). If a shaft is twisted or broken, the Yukon 1541H alloy replacement axle for the Dana 60, 70 and 80 ($326.70) is the upgrade.
Pinion Bearing Whine
A high-mile Dana 70 that whines at cruise usually has pinion bearings that have lost preload, or gears worn from low oil. Any in-and-out clunk at the yoke means loose bearings. A hum that tracks road speed is more likely a hub bearing. See our whine diagnosis guide.
Most Dana 70s set pinion preload with selective shims, not a crush sleeve, so cranking the pinion nut down does not fix anything. The Revolution Gear 1994-2002 Ram Dana 70 rear master kit ($229.99) covers the common Ram axle. Pull carrier bearings with a Dana 30/60/70 clamshell carrier and pinion bearing puller ($170.99). The carrier comes out by spreading the housing a few thousandths with a Dana 30-80 housing spreader ($138.99). If the yoke has a groove where the seal rides, replace it; the Spicer Dana 70 29-spline companion flange ($87.99) fits many trucks. See our pinion seal guide.
Hub Bearing and Seal Leaks on Full Floaters
Gear oil runs out the tubes to lube the hub bearings, so a worn inner hub seal puts oil on the brakes and a torn flange gasket leaks out the front of the hub. Oil on the inside of the wheel and a grabby brake on one side is the classic sign. Check the vent first; a plugged one pressurizes the axle and pushes oil past every seal.
Hub bearing adjustment matters. The usual method is to seat the bearings while spinning the hub, back the nut off, snug it to a low spec, then lock it with the washer or lock nut. Too tight cooks the bearings; too loose wears the seal. A 13-piece spindle nut socket set ($158.99) covers the common hub nuts. Replace soaked shoes or pads.
Powr-Lok Wear
Many Dana 70s have a clutch-type Powr-Lok. Worn clutches or missing friction modifier make it chatter in turns or act open on ice. Try fresh fluid and modifier first. If it still chatters, rebuild it with the Yukon Dana 60 and 70 Powr-Lok clutch set ($189.89). If the case or cross shafts are worn, the Yukon Powr-Lok carrier case for the Dana 70, 4.10 and down ($1,065.89) replaces the case, and the Yukon Dura Grip for the 32-spline Dana 70, 4.10 and down ($1,330.50) is a complete new limited slip. See open vs limited slip vs locker.
Regears
Factory ratios run about 3.54 to 4.56 depending on truck and year, and the carrier changes between the 4.10-and-down and 4.56-and-up ranges. The Yukon 3.73 gear set for the Dana 70 ($892.78) suits highway towing on stock tires. See picking a ratio.
Setup is where regears go bad. Pinion depth is a shim under the inner pinion race; carrier preload and backlash are shims behind the carrier bearings. Backlash is typically around .005-.010 inch; follow the gear maker's spec. Use a dial indicator with magnetic base ($47.99) for backlash, an inch-pound torque wrench ($79.99) for pinion preload, and new ring gear bolts with thread locker. Our backlash and pinion depth setup guide.
What It Costs: DIY vs Shop
| Repair | DIY | Shop (rough) |
|---|---|---|
| Pinion seal only | About $25-$70 | About $250-$450 |
| Hub seal and bearings, one side | About $60-$150 | About $300-$550 |
| Axle shaft replacement, one side | About $330-$450 | About $450-$700 |
| Powr-Lok clutch rebuild | About $200-$280 with fluid | About $650-$1,100 |
| Carrier and pinion bearing overhaul | About $250-$550 plus tools | About $1,000-$1,600 |
| Regear with master kit | Parts about $1,100-$1,500 | About $1,700-$2,700 |
| Regear plus new limited slip or locker | Parts about $2,200-$3,000 | About $3,000-$4,000+ |
DIY numbers assume you own the puller, spreader, dial indicator and a press. A Dana 70 holds roughly 3.5 to 4 quarts; fill to the bottom of the fill hole with the gear oil your manual calls for, plus friction modifier with a Powr-Lok. The differential fluid change guide covers intervals. For a dented cover, the Yukon Hardcore cover for the Dana 50, 60 and 70 ($333.89) is the fix.
Parts and Tools for the Job
| Need | What We Carry |
|---|---|
| Ram bearing whine | Revolution Gear Ram Dana 70 rear master kit ($229.99) |
| 70-U full overhaul | Yukon Dana 70-U master overhaul kit ($544.46) |
| Chatter in turns | Yukon Powr-Lok clutch set ($189.89) |
| Regear | Yukon Dana 70 3.73 gear set ($892.78) |
| Broken or twisted shaft | Yukon 1541H alloy axle ($326.70) |
| Pulling carrier bearings | Clamshell carrier and pinion bearing puller ($170.99) and housing spreader ($138.99) |
More bearing kits are in our rebuild kits section, gear oil and friction modifier in fluids, and pullers and gauges in tools. CoreTransmissionParts.com carries transmission and transfer case parts if the noise is further up the driveline.
Quiet the Whine for Good
A worn pinion bearing only gets louder under load. Replace the bearings, races and seal in one pass and get back to towing.
Shop the Dana 70 Master Kit → Gear Oil and FluidsFAQ
How do I tell if I have a Dana 70?
Look for a 10-bolt cover on a center section with a ring gear of roughly 10.5 inches, and check for a tag on a cover bolt. Without a tag, a 70 is visibly bigger than a Dana 60 and smaller than a Dana 80, and most have full-float hubs.
Is my Dana 70 32 spline or 35 spline?
Most Dana 70s use 32-spline axle shafts, but some heavy-duty versions run 35 spline. On a full floater, pull the flange bolts, slide a shaft out and count the splines before ordering.
Why is my Dana 70 leaking gear oil at the wheel?
On a full floater the hub bearings run in gear oil, so a worn inner hub seal, a torn axle flange gasket or a plugged housing vent all push oil out at the wheel. Fix the vent first, then replace the hub seal and gasket.
How much does a Dana 70 rebuild cost?
A DIY bearing and seal overhaul runs roughly $250-$550 in parts. A shop overhaul with the existing gears is usually about $1,000-$1,600. A regear with new ring and pinion and a master kit runs about $1,700-$2,700 at a shop, and adding a new limited slip or locker can push it past $3,500.