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Preparing for wheel bearing job...


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I have been gearing up to do the rear wheel bearings and seals on our 99 outback wagon for some time now. I think I finally have the parts and tools to complete the job but I have a question.

 

The subaru procedure on the endwrench site says NOT to add grease to the factory packed bearings.

 

from http://www.endwrench.com/current/Current6/03/WhBearRep.pdf

 

*Prepare the new tapered roller

bearing for installation. Do not

remove the bearing stay (plastic

piece inside the bearing) at this

time.

Note: Do not disassemble the

bearing. Do not add any grease

to the bearing.

*Set the bearing assembly into

the bearing housing.

 

As many of you can imagine this makes me a little nervous. Not only does the technique differ from what I have done in the past, but I seem to remember someone on this board recommending cleaning and packing the bearing.

 

PS: I will list the parts I plan on using for those interested. All OEM.

 

28015AA110 OIL SEAL IN2 RR*

28015AA100 OIL SEAL IN1 RR

28015AA050 OIL SEAL OUT RR

28016AA030 BEARING AY R 4WD

28044AA000 NUT (AXLE) [EDIT, 01/18/04]

 

* has grease pre-applied on the seal. Unusual in my experience.

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The way I understand it is: At first when they were seeing a lot of repete wheel bearing failures, they said the grease that came in the new bearing was just a rust prohibitor, and that it needed to be cleaned out and repacked with good wheel bearing grease.

Don't hold me to this, it is just what I was told by a Subaru Tech that used to work for the dealer.

 

Then they decided that some of the hubs were out of round. I think this is mentioned in the latest write-up. Or that the hub or bearing was beeing damaged when using a press.

 

So now they say the grease in the bearings is OK (looks like the same as was always in the replacments).

 

Anyhoo.........If you want to clean and repack the new bearings I'm sure it won't hurt anything. I've done some without repacking and some that I did repack. Haven't had a come-back yet.

 

Happy wrenching:D

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Thanks for the advice.

 

I think I will use the bearing as is. Assuming they install the bearing the same way at the factory, I should be able to get another 145k miles out of the ones I install.

 

Do you use a hydraulic press? Do you have the special tool they use to measure the depth of the hub once installed? I am going to have to improvise that tool a bit. I am going to be using a hub tamer.

 

Thanks again!

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Used to use a press. I now have a hub tamer type tool, so I can do the rear bearings "on car". On the front I pull the whole strut assebly (don't seperate the hub from the strut or you will have to pay for an alingment when your done) out to do the bearings. I find it easyer this way than doing it "on car".

I don't measure the hub installed depth.

 

To be quit honest with you I don't really think that the problem with rear wheel bearings has anything to do with grease or replacment procedure. As you will notice in the End Wrench artical, Subaru has "authorized" the installation of a taper roller-type bearing as a replacement in Impreza & Forester. (Somthing I've been doing for the last 1+year, with out Subarus blessing) The taper roller bearing being the same bearing in the Legacy & WRX, whitch you don't see going bad like the Impreza & Forester bearings. In short I think they tried saving money on bearings & the customer got what Subaru payed for.

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If possible guys (99obw and Wawaker) could you give the board a detailed report on how you did. Would be useful for me cause i will have to do this probably sooner than later.

For one, what's the advantage of a «hub tamer» over a press? Does'nt either one have to exert a pressure on the bearing to push it in? why would one damage the bearing or races and not the other?

Just want to do this myself if possible and not ruin anything.

Thanks for the info already given.

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WAWalker,

 

I am doing the rear bearings at the same time as the rear struts. I assume I can swap the struts out without needing an alignment. Is that correct?

 

frag,

 

I will certainly post my experience here when I do the job. This weekend a friend of mine is coming over and we are doing brakes, rear wiper motor, and a timing belt job on his '97 legacy wagon. Maybe next weekend I will get to work on our '99.

 

To me the advantage of the hub tamer is doing the job on the car. WAWalker suggested removing the knuckle with the strut, eliminating the need for an alignment, which is a really cool idea. I don't know if using a press actually damages anything.

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99obw,

When doing the rear struts you really don't need to get an alignment. When doing the front struts you do need an alignment because the caster/camber adjustment is in the top bolt that bolts the strut to the knuckle.

 

Doing the rear bearings on the car is easy enough with a hub tammer. But since you are doing struts too.......................

 

Doing the fronts on the car I find there is to much stuff in the way. Thats why I take the front strut assembly out, since it's only 3 more nuts that are very easy to get to.

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You need to repack the bearings with good wheel bearing grease. The stuff in there is just packing grease.

 

Technically, if you mess with anything you should get an alignment, even if you don't dissamble the hub from the strut.....it's going to be off slightly from what it was. The same with the rear.

 

I'd sooner pay for an alignment then wear my tires down.

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Originally posted by WAWalker

99obw,

When doing the rear struts you really don't need to get an alignment. When doing the front struts you do need an alignment because the caster/camber adjustment is in the top bolt that bolts the strut to the knuckle.

 

Doing the rear bearings on the car is easy enough with a hub tammer. But since you are doing struts too.......................

 

Doing the fronts on the car I find there is to much stuff in the way. Thats why I take the front strut assembly out, since it's only 3 more nuts that are very easy to get to.

I usually do have an alignment done when I have had the front apart, but I have never had an alignment done when I have had the rear apart.

 

I don't have or have access to a hydraulic press, so the hub tamer works well for me whether I remove the struts or not.

 

Originally posted by Legacy777

You need to repack the bearings with good wheel bearing grease. The stuff in there is just packing grease.

 

Technically, if you mess with anything you should get an alignment, even if you don't dissamble the hub from the strut.....it's going to be off slightly from what it was. The same with the rear.

 

I'd sooner pay for an alignment then wear my tires down.

I usually like to err on the side of caution, and I know that the premium wheel bearing grease I have will work very well, so maybe I will change my mind and repack the bearings.

 

I wasn't going to replace the struts yet but the left rear decided it wanted to freeze solid. :banghead: I think I will wait until I do the front struts to have a 4 wheel alignment done.

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Could replacing only the rear struts be a mistake? That is going to make the rear very stiff compared to the 145k mile old front. I don't want to wait for very long to do this job, nor do I want to fork out more money for parts.

 

This is the first car with 4 struts I have worked on. I do remember having some strange handling on cars where I replaced the rear shocks but left the old front struts.

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Suppose, you wanted to use the press for rear bearing work. Will the assembly sit squarely on the press plates? I'm picturing a funky looking assembly that holds on the strut and other stuff so there're ears and irregular shapes protruding from it!

 

I need to this on my wife's '95 as it's in the "howling" mode right now. I have a press but don't have easy/cheap access to a hub tamer tool. Wish I could rent these things but my local Murray's or Autozone don't seem to carry them. I could be mistaken of course.

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Originally posted by alia176

Suppose, you wanted to use the press for rear bearing work. Will the assembly sit squarely on the press plates? I'm picturing a funky looking assembly that holds on the strut and other stuff so there're ears and irregular shapes protruding from it!

 

I need to this on my wife's '95 as it's in the "howling" mode right now. I have a press but don't have easy/cheap access to a hub tamer tool. Wish I could rent these things but my local Murray's or Autozone don't seem to carry them. I could be mistaken of course.

 

That last time I used a press to replace a bearing that is exactly what I found. I had to shim the knuckle all over the place in order to get it to sit on the press such that I could press parallel to the axle hole in the hub. With the rusted snap ring and the total lack of appropriate dies to press with, I think it took me and my stepdad about 4 hours to press the hub out, old bearings out, new bearings in, hub in, and install the seals. That press is no longer readily available to me so I bought the hub tamer.

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I picked up my bearing and three oil seals yesterday. I see what your confusion with regards to the repacking issue. Mine came with grease and it's visible. It smells like grease too. I can't say I look forward to taking the whole set apart and regreasing everthing. Howevr, if it's required, I'll be happty to do so. The parts guy said it's indeed a sealed bearing or at least pre-greased. Let me know what you end up doing!

 

Ali

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I still haven't made up my mind. It sure seems to me that subaru intends for the tech to leave the prepacked grease in the bearing. One of the seals I bought has grease pre-applied as well, and I am hard pressed to think that is "packing grease" on the seal.

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  • 2 months later...

Well, I finally tried to replace the rear bearings this weekend.

 

:banghead:

 

I borrowed an air compressor and impact wrench. Everything I had had apart in the past came apart easily. With a little persistance and the impact wrench the axle nuts came off. What I didn't know was the lateral link bolts are exposed for most of their length on the inner side of the knuckle. In this geographic region that means severe corrosion. I got both of the nuts off easily but the bolts wouldn't come loose from the knuckles. I used a lot of penetrating oil over a 24 hour period. I did manage to get the right side free. I am afraid that if I torque any harder on the left side it will break. I am quite familiar with breaking car parts.

 

I put it all back together. I am planning on buying the lateral link bolts and nuts and trying again next weekend. That way breaking them isn't a problem.

 

I did manage to change the rear diff lube with some fresh Mobil 1 75w-90.

 

What a waste of time.

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Sorry to hear that dude. I can relate with the lateral link bolt issue! The bolts are a bit pricey FYI! I did manage to ruin one of the bushings while gettting the bolt out! The bolt froze to the inner shell of the bushing. I'd order a set of bushing just to play it safe.

 

Good luck.

 

Ali

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If you do end up wanting to remove links, keep in mind that one of the bushings at that (toward the diff) end is used for toe adjustment. So, keep an eye on it as you remove the nuts/bolts. I'd mark the washer. I'm talking about the link that's closer to the front of the car. On that particular one, don't turn the bolt, only the nut. The bolt has squared off body to prevent turning.

 

 

Have fun,

 

Ali

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Originally posted by 99obw

That makes sense, one of the links has a big black plastic thing on it that looks like an adjuster.

 

Well, not really! The black plastic thing is simply a cover for the nut. You have to remove it in order to get access to the adjustor nut.

 

Ali

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