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Old Axle Autopsy - Buyer Beware

Dana 30 Axle
Christian Hazel
| Brand Manager, Four Wheeler
Posted August 6, 2013

What to Look For When tearing down a Dana 30

Ever stoke something up in your head, only to have it wind up a huge disappointment? Older folk may remember sending away for the flying hovercraft kit in the back of Boy’s Life magazine, only to have an envelope with crappy instructions on how to cannibalize your mom’s vacuum cleaner arrive weeks later. Younger folk may have an analogy involving some phone app thingy that didn’t upload your posts on all your social media sites. Damn kids. Or maybe you got a chick’s phone number and she wound up having a bigger dingle-dangle than yours. Whatever the case, disappointment happens, especially when buying used automotive parts.

We lucked into a honey of a narrow-track Dana 30 for cheap. Visions of simply changing the lube and bolting it into our vintage Willys passed through our minds as we looked it over. Sure, the bill of materials on the axletube indicated the housing came from an ’81 CJ-5 and the 11⁄8-inch disc brakes and six-bolt caliper brackets were from ’77-’78 Dana 30, but the swapped-in 4.88 gears, Eaton Truetrac, and wheel spacers blinded us to that inconsistency. We argued logic that the previous owner simply wasn’t afraid to mix and match parts. Wrong.

As it turns out, instead of a flying wonder hovercraft we wound up with a wheezy vacuum motor stuffed in a cardboard box. Foiled again. But it isn’t all bad. In the end,w we’ll be able to use some of the parts on our other project Jeeps, sell some others to cover our costs, and share with you some things to watch for and consider the next time you’re scouring the want ads for a used axle.

Step By Step

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  • 1. One of the hubs wasn’t engaging the axleshaft when we spun the hub/rotor. This can often be attributed to improper hub assembly so it didn’t immediately raise a red flag. Sometimes just pulling an external-body hub off and reinstalling is enough to fix the issue. In our case, the splines in the driver-side hub were stripped and damaged. Rebuild parts are available from Warn, but this breakage proved only the beginning.

  • 2. The hub bearing preload was off and we could wiggle the hub/rotor assembly up and down. We popped off the calipers and, although nasty, found the pistons weren’t seized. The rotors could probably be machined and reused, but we’ll go with new ones from a local parts store.

  • 3. If you’re buying an early axle, it’s usually easy to remove the external hubs. If the spindle nuts are chewed and show signs of chisel marks and the lock washers are hammered like these, it’s often a sign of shoddy workmanship. If they can’t bother using a spindle nut socket, chances are maintenance on the rest of the axle is equally bad.

  • 4. We pulled off the calipers, slid the hub/rotor assemblies off, and then removed the six spindle nuts. The’77-’78 Dana 30s have these six-bolt caliper brackets that can be retrofitted to earlier Dana 25 or Dana 27 axles. Score. Later Dana 30s used a two-bolt caliper bracket that attaches to the knuckle and can’t be retrofitted on closed-knuckle axles.

  • 5. Another fun surprise greeted us when we tried to remove the axleshafts from the housing and found them firmly wedged in place. If you have to pry out axleshafts, you can pretty much write off the housing. The seal surfaces of both shafts were galled and damaged, and the splines on the driver-side shaft had been eaten away by the hardened teeth of the Truetrac side gears.

  • 6. Another sure sign of bad things to come are these spindle camber adjustment shims. These wedge-shaped shims are often used to regain camber on a bent housing. Seeing them is usually not a good sign.

  • 7. While separating the hubs from the rotors, three of the wheel studs literally fell out as soon as we touched them. Normally the knurling on the stud is designed to fail before stripping the bore of the axleshaft or hub into which it’s pressed. However, in this case the stud bores were completely stripped. Unless we wanted to get butch and tack weld new studs in, these hubs are worthless.

  • 8. We popped the knuckles off the housing and found the ball joints were pretty hammered. All the grease had dried and crusted up. We tried pressing out the ball joints with our Harbor Freight ball joint tool, but they were frozen in place. We’ll let them soak in penetrating oil for a few weeks before giving it another go.

  • 9. Our spindles were hammered—literally. In addition to peen marks from being hit with a steel hammer, the bearing surfaces were galled, pitted, and blued in places from the heat of spun bearings. We wouldn’t reuse them.

  • 10. Our axle was wearing some heavy-duty steering linkage with rod ends. Rather than drill out the taper for larger bolts that fit the bores snugly, the previous hack used smaller bolts that fit the taper minors. It’s hard to see in the photo, but the loose fit allowed the bolts to wobble, thereby oblonging the tie rod tapers. We’ll have to ream the tapers for larger tie-rod ends or drill for larger rod end bolts, but the knuckles are still usable.

  • 11. Popping the diff cover revealed a bunch of chunked metal in the oil. Miraculously the 4.88 gears looked okay. We marked the carrier caps to keep them in the same orientation (just in case the housing wasn’t junk) and pulled the carrier bearing caps. The diff literally almost fell out. That’s another bad sign. Normally carrier removal requires a couple long prybars or a case spreader.

  • 12. The pinion felt gritty and didn’t spin freely and evenly. We gunned off the pinion nut, knocked off the yoke with a dead blow, and removed the pinion gear. The yoke seal surface was only slightly grooved, but looked like it would polish up for reuse.

  • 13. The outer pinion bearing rollers were pretty loose and the race had telltale indications of wear. You can see where the individual bearing rollers were starting to eat into the race. Left unfixed, the bearing would’ve no doubt disintegrated, taking the ring and pinion with it.

  • 14. Our carrier bearing rollers were pretty loose in their cages, and once again we saw telltale signs of galling, grinding, and excessive heat indicative of spun bearings. Even if the axletubes were straight, we doubt we’d run this housing again.

  • 15. With all the metal floating around in the gear lube, we weren’t hopeful for the Truetrac. We pulled it apart for cleaning and inspection. Despite signs of normal wear, the side gear splines, gear teeth, and bores were all undamaged and in good condition, which is a testament to Eaton’s manufacturing.

  • 16. The coup de grace was where the axleshafts on both sides had actually ground away the top portion of the inner axle seals and into the centersection. Somebody probably jumped the Jeep in which this axle was installed, severely bending it. The bent tubes weren’t very noticeable thanks to the camber adjustment shims.

  • 17. Rather than a complete axle to swap in our early Willys, we wound up with a pile of parts. So instead of swapping, we’ll reuse the disc brake components on our M-170’s Dana 25 or J4000’s closed-knuckle Dana 44 and will sell the wheel spacers, knuckles, Truetrac, and 4.88s to break even. Sometimes that’s the way it goes with old axle parts.