replace bearing in front hub assy?

In my opinion, this isn't too big of a job. Your experience with rotors and calipers will come in handy since they will have to come off in order to get the axle shafts out. The biggest problem that I had on my '98 Cherokee was getting the hub assembly itself out from the steering knuckle.

I suggest lots of Liquid Wrench or PB Blaster. That, and once you've loosened the bearing assembly's retaining bolts from the backside of the knuckle, tap on the retaining bolts in order to persuade the bearing assembly from the knuckle. Use a socket that you don't really care about while pounding... :)

And to offer my input on Stephen's original question, I haven't heard of anyone pressing new bearings into the old assembly. I'd worry about getting it to seal properly and retain its grease once it is pressed back together.

I think I paid about $140 for mine. $180 sounds a little bit too high -- unless you're talking about dealership prices...

My $0.02

-John

L.W. (ßill) Hughes III did pass the time by typing:

Just a minor suggestion. If you have someone press the brakes getting that 36mm nut broken loose is a lot easier.

Then take the caliper off. :)

Or you can get it started with the wheel on, just don't loosen it yet.

L.W. (ßill) Hughes III did pass the time by typing:

Cool.

Wonder if they can fit 32s to em. :)

i'm not sure about the clearances involved since i haven't popped the bearings on my 93 yj yet, but chrysler solid front axles use the same bolt-on bearing assembly. hopefully it's close to the same idea here:

doing the left bearing, unbolt 4 bolts, and turn the wheel to the right all the way. rotate the axle until the stub axle yoke is flat. wedge an impact socket between the stub axle yoke and the axle housing. turn the engine on and then turn the steering wheel to the left until the axle pushes the bearing out of the hub. opposite for right side.

Mine was suprisingly easy... the manual's not that much help. You'll need a great honking 36mm socket... Autozone has one that you can buy, then return for the same money, sweet!

Basically, pick up both fronts (easier to move the hub back and forth) and put 'er on jack stands (break the lugnuts loose first!). Take off that side's tire. Either have someone hold the brakes (thanks Doug) or, as I did, put a crowbar inside the axle yoke to prevent spinning. Remove the cotter key and retainer (notice the cute springy washer, save that too) and loosen the giant nut (lefty loosey, both sides).

With a 13mm 12pt socket, take off the caliper bolts. *Before* you pull off the caliper, bend it from side-to-side to bleed back the piston... makes re-installation much easier. Lay the caliper on the frame (*don't* hang the caliper by the tube). Work off the rotor, set aside. Find the three bolts that hold the hub assy on (12-point heads), find the outboard ends, and soak with a liberal dose of Knock-er Loose... you can also wire brush the ends of the bolts, to get more rust off (mine weren't that bad, after only three years). Take a break. After the break, pull the hub bolts out (work the steering knuckle back and forth to get access, now you're glad you lifted both sides, unlock the steering!). *Now* you have to get the hub out... the only thing that's holding it in is rust. I used a big heavy bar... don't pry on anything, just hold the bar, one hand on each end, and yank-hit the flange of the hub toward you. Alternate top-bottom, or you can try Ben's genius way:

Since I've found that the assembly is trash, anyway, you can beat the hell out of it with a hammer if you want. When it frees, you can either take the hub and axle out together, or leave the axle in (this is a good time to do the U-joint, more big hammer work). Since I'd already done the joint, I just took off the big nut and pushed the axle in as I pulled the hub free.

Notice how pretty the new assembly is! Expensive, too...

Sand the inside of the knuckle where the new hub goes... grease it (and the splines of the axle) too. Put the disk shield on (not backwards!), then put the hub assy on. I put never-seize on the bolts for the hub after cleaning them up on the bench grinder's brush (everyone should have one!). Bolts are torqued to 75ft/lb. Then big nut, torqued to 175. The rest is just the reverse of removal. __ Steve .

Looking at the pics on the web site Bill sent, I can't tell if the hub assembly has both inner and outer bearings. This pics seem to show inner bearing still part of the jeep even after the hub is pulled off. Will replacing the hub replace both bearings?

Thanks!

Stephen Cowell wrote:

The front hub assy is a one-piece pressed together ball bearing as I recall, similar to those used on fwd cars. I read a web piece several years ago where some guy had devised a way to just replace the bearing. However, best to just toss the worn out POS and replace it with an all new assy. Easy as pie to replace if you have the right tools. It helps if you give the splines on the outer axle shaft a good soaking with Liquid Wrench, etc. the night before. As I recall from one I did a while back, I broke the hub nut loose with the wheels on the ground, used a slide hammer to pull the hub & axle assy free from the knuckle, then used a hub puller to break the axle free from the hub itself. Went back together very easily.

FWIW, considering all the stress we put on these things (offset wheels, big tires, lockers, weight, etc.) they seem to hold up better than one would imagine. Still, not as stout as the good old inner & outer standard hub. Just another gift from the corporate cost-cutters.

Actually, in the picture Bill is referencing below, you can only see the outer bearing. There are bearings on both sides of the mounting flange. You can see the "space" for the other one here:

Funny, Timken doesn't mention the K-Car in this brochure:

They mention that Jeep has been using their hub in the front wheel assembly since 1990 -- long after the K-Car's _fortunate_ demise... They also mention the fact that GM and Ford also use this technology on various vehicles.

Of course, I won't go into whether or not this assembly _should_ be used on any "real Jeep"...

:)

-John

I've been called worse. :)

While this isn't the exact version that's on the Jeep, it is similar to what the old one from my '98 Cherokee looked like when I tore it apart.

Did "older" versions that you've torn apart have only one bearing?

-John

In Bill's pic, the assembly is sitting wheel flange down. The side of the assembly facing up is what fits into the knuckle bore, so that would be the "inner bearing" equivalent. It will separate between the wheel flange and the trangular knuckle mount, (ask me how I know) though it isn't desgined to do that normally.

There is no bearing on the outside of the wheel flange. The axleshaft simply slips into the splined bore in the bearing assembly, and the axle nut (and washer IIRC) threads on the end of the axleshaft.

• * * Matt Macchiarolo
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I suspect that I know exactly how. You probably did the same thing that I did when trying to get the assembly off. You used a puller, didn't you? :)

Now I wish that I had taken pictures during the replacement, but I'd swear that mine had two bearings -- see my other reply to Bill's post and a link to a cutaway of a similar model available from Timken.

I'm more than willing to believe both yourself and Bill. I should know better than to disagree with Bill. :)

I guess that I'll have to wait another 90,000 miles before I can disassemble my "replacements"... :)

-John