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| While changing wheels in order to get a small air leak fixed, I noticed that there was a very small amount of "wiggle" in both of my front wheels. If I jacked the vehicle up in front and grabbed the tire at the top and bottom, I could rock the wheel-and-tire a little bit, maybe 1/16 of an inch at the perimeter of the tire. I compared this with another vehicle with the same Dana 30 axle, and there was no play. I checked to make sure the play wasn't at the ball joints - it wasn't. It's the wheel bearings. Both sides had about the same amount of play. |
| After doing some research on changing (or repacking) wheel bearings on YJs (all of which come with the Dana 30 axle in front), I discovered that the front wheel bearings are "not a servicable item" on this vehicle. There is a sealed "hub and bearing assembly" that must be replaced as a unit. That's a bit of a drag, since the unit isn't cheap. But on the upside, this is the first time in this vehicle's 113,000 mile lifetime that I've had to muck with them at all. | |
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| I did some searching around on the net and let my fingers do the walking through the local phone book. Almost every source that had or could get the part wanted between $160 and $198 for the part. The one exception was Autozone, which wanted $101 each for Timken brand assemblies. Of course I had to do some legwork - most of the Autozone stores here in the Kansas City area didn't stock the part, and the ones that did only had one each. So, two Autozones later I was ready to begin. |
| The hub and bearing assembly is held on by the large axle nut and three bolts that come in from behind the steering knuckle (the part that rotates on the ball joints). | |
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| I picked up some advice and tips from the swbjeep mailing list that was very helpful. The best tip was to loosen the axle nut while the wheel is still on the ground - otherwise the whole wheel would just rotate when I twisted the wrench (the bearings weren't that bad, yet). I did have to yank the wheels to pull off the plastic hub covers, in order to expose the axle nuts. Then I put the wheels back on and lowered the jack. I removed the cotter pin and the doo-dad that the cotter pin holds in - it's a stamped socket-kinda-thing that keeps the axle nut from unscrewing. |
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| I doused the axle nut with some penetrating oil, then tried my 1/2-inch drive socket wrench with a 36mm socket on it. No budge. I borrowed the handle from my hi-lift jack for some extra torque, and was able to loosen the axle nut on each side. |
| I did the same for the other side of the vehicle, then put jackstands under the spring perches to support it. I removed the wheels, the brake calipers, and brake disks. | |
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| The three bolts on the back of steering knuckle (which is what the hub-and-bearing assembly attaches to) were a bit tough to get out. They require a 13mm 12-point socket. Two of them are visible in this photo - one just below the top ball joint (ball joint has the cotter pin on it), and the other at the bottom edge of the picture. |
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| The bolts weren't budging, even with some penetrating oil on them, so I resorted to tapping the handle of the socket wrench with a hammer in order to loosen them. I've got an impact wrench, but there's not enough room to get a straight shot at these bolts, so I had to resort to other means. Once loosened, the bolts came out without further complaint. |
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| I removed the axle nut (which I loosened earlier) and the washer behind it (washer's still there in this photo, and the three 12-point bolts that hold the assembly in from behind can be seen on the floor). I put some pentrating oil where the assembly meets the brake dust shield. Then pulled on the hub. No budge. I sprayed some more penetrating oil on the joint, and let it sit overnight. |
| The next morning neither hub would budge. I tapped around with a hammer hoping they would loosen and fall out. I considered a gear puller on the axle stub and behind the wheel flange, but that would probably just damage part of the axle - the axle had some play and I could slide it in and out a small amount, so the assmebly was not stuck on the axle shaft. It had its claws firmly dug into the steering knuckle. I tried putting the three bolts back in from behind, and tapping on them with hammer in order to force the assembly out. I couldn't get it to budge with some hammer taps, and I didn't want to really whack on them for fear of damaging the threads on the bolts or in the steering knuckle. | |
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| After considering several options, I ended up with a slide hammer. Mine has a box-end thing on the business end, with a hole. The hole was too big for the lug nut studs (hole was larger than the diameter of the nuts), but I was able to hook enough of the edge of the box-end on the back of the hub flange to make progress. It was slow, and took a LOT of whacking. As it started to budge, I put in some more penetrating oil, and got the damn thing out. The other side was just as difficult. |
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| I'm sure I did further damage to the bearings in this process, but they were doomed for retirement to paperweight status, anyway. |
| I cleaned out the bore in the steering knuckle, and wiped some anti-sieze in there. I put some anti-size on the new assemblies, and put them in. I cleaned up the old bolts with a wire brush, put some anti-seize lube on the threads, and popped 'em in. I cleaned up the axle nut, the big washer, the spring behind the stamped socket-like doo-dad, and the cotter pin, and installed those (with some anti-sieze in the threads). I torqued the rear bolts to spec. | |
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| Darn, I didn't get any good pictures with the shiney new hubs on. You can see a bit of them in the picture I took after the brakes were back on. |
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| I put the wheels back on and dropped it to the ground in order to torque the axle nuts. |
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| Wheel hub covers are back on, and I'm ready for another 113k miles! |
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