18 replies to this topic

[Andyjo]

!!!
freaking impreza rear ends... i've got some wheel bearings going AGAIN (3rd time) but this time i'm not going to drop 300 bucks in the shop, i want to do it myself this time, SOOO what do i need (part Numbers & Tools), and how do i do it...
Pop the axle nut off, and pull out the axle i'd suspect.. and then what? should i go rent a bearing puller from autozone/advanced or something?
This could be something for the ultimate subaru repair manual
oh yeah, i'm running an impreza obs, 97, i need legacy bearings though... right?

[Chef]

Are they being packed with grease before being installed? From my understanding subaru bearings come with "shippng grease" meant to protect form corrosion, and need to be repacked in bearing grease before being installed. There seems to be some confusion about this even at dealers.

Worth checking into. I'd definitely go back to the shop that did and ask them what their procedure is, and if they omit the part about packing with grease, I'd tell them how it's done and have them do it for free this time.

!!!
freaking impreza rear ends... i've got some wheel bearings going AGAIN (3rd time) but this time i'm not going to drop 300 bucks in the shop, i want to do it myself this time, SOOO what do i need (part Numbers & Tools), and how do i do it...
Pop the axle nut off, and pull out the axle i'd suspect.. and then what? should i go rent a bearing puller from autozone/advanced or something?
This could be something for the ultimate subaru repair manual
oh yeah, i'm running an impreza obs, 97, i need legacy bearings though... right?

[tcspeer]

I dont know about the back but on the front I took the spindle and hub off and carried it to a small shop they pressed it out and put the new bearing in for 30.00 dollars. You can get a small press from Harbor Freight for under 200.00 dollars, you will also need a bearing seperator tool I think they are around 30.00 dollars.

!!!
freaking impreza rear ends... i've got some wheel bearings going AGAIN (3rd time) but this time i'm not going to drop 300 bucks in the shop, i want to do it myself this time, SOOO what do i need (part Numbers & Tools), and how do i do it...
Pop the axle nut off, and pull out the axle i'd suspect.. and then what? should i go rent a bearing puller from autozone/advanced or something?
This could be something for the ultimate subaru repair manual
oh yeah, i'm running an impreza obs, 97, i need legacy bearings though... right?

[dxrflyboy]

Autozone may have a "Hub Tamer" for rent that will help you remove the bearing from the knuckle on the car. You will still need to remove the long bolt on the bottom of the knuckle to pull it out for axle removal. Chances are, the bolt is rusted in place and will require a breaker bar with a "cheater pipe" over it to break it loose. Subaru does instruct technicians to replace the "shipping grease" with bearing grease when installing the new bearings. The "shipping grease" is pretty much just diluted candle wax that gels up in a short time. I use a bearing packer, where possible, and "pump" the "shipping wax" out of the bearing and fresh bearing grease in. Also, make sure not to overtighten the axle nut. Unlike most other makes, tightening the axle nut all the way puts too much pressure on the wheel bearings and you will barely be able to turn the hub by hand. This will destroy the bearing in short order. You must be able to turn the hub by hand without too much effort.

[dxrflyboy]

Also, replace all 3 grease/dust seals.

[88HatchMonster]

For the record, the ball-type bearings that came stock in the rear of the Imprezas and failed so often are obsolete. When you order rear wheeel bearings from the dealer for your 98 Impreza or whatever you get tapered roller bearings, part #28016AA030. This is in fact the same bearings that came in Legacies through 1999. This has been in effect since August 2001.

This is what Subaru has to say about the whole "shipping grease" issue:

"The new genuine Subaru rear wheel bearings are not to be packed with grease of any kind. The bearing is ready to install out of the box."

This is from an Endwrench article found here: http://endwrench.com...heelBearing.pdf

In the article, they claim that improvements to the bearing in manufacture and an installation procedure using their special "hub tamer"-like tools will "reduce the possibility of repeat premature failures."

Why do these bearings constantly go? Nobody, I mean nobody really knows. Apparently not even Subaru. Even the new bearings, installed using their new procedure go bad after 20-40K.

There are many theories as to why they go. One I am leaning toward lately is that the outer CV cup gets rusty and compromises the inner seal allowing water and dirt into the bearing. I drive my OBS all winter in Upstate NY just like Andyjo, and it's HARSH. I can just imagine the many times I've driven home from work 1 1/2 hours through the salty slush and parked the car, with every inch of the underbody caked with salty, dirty snow. And then it melts and freezes etc. Magic fairies or even three fricken seals aren't keeping that crap out of my wheel bearings...

Anyway, Approximately 18 months ago I had a local garage install new left rear wheel bearings on my 98 OBS. 12 months later they were completely trashed. This time I did the repair myself. When I pressed out the hub--ball bearings fell everywhere. The shop had used the parts supplier CarQuest and installed more uber-crap ball bearings, and no suprise they only lasted 12-15K if that. So I installed the updated OEM tapered roller bearings myself. I figured I was golden. No problems so far.

BUT.... Last month my other side rear bearings went on me. These had been replaced at a dealership a few years ago. I thought "No big deal, they probably put the crappy old ball bearings that they still had on the shelf in it and that's why they went..." Unfortunately, when I pressed these out, I was dismayed to find, *gasp* tapered roller bearings. No doubt installed with their fancy low-force Kent Moore tools.

SO: If you have an Impreza that eats rear wheel bearings you are doomed to repeat failures whether you put in Legacy bearings or not. The Legacy bearings definitely do last about twice as long though...

OK, so now that my rant is over, does anyone have a real solution here that is proven to work? I'm not talking anecdotal advice on replacing wheel bearings, how to pack the bearings etc. What is wrong with these cars and how can we get at least 80K or 90K out of a set of bearings? Please only respond if you have SOLID info on this SPECIFIC subject: Impreza rear wheel bearings. Thanks.

[GeneralDisorder]

Figure out a way to install EA series rear bearings. They last forever. I've seen originals in good shape after 200k miles.

GD

[88HatchMonster]

Figure out a way to install EA series rear bearings. They last forever. I've seen originals in good shape after 200k miles.

GD

That is sooooo what I've been thinking

My two hatchbacks are a little "clunkier" to drive, but they'd never think of dropping bearings every couple thousand miles...

[WAWalker]

The fancy Kent-Moore tools are OTC Hub Tammer tools. The reason for the "low force" installation procedue is to prevent deforming the hub or bearing race when removing and installing the bearing. I believe that most repeat failures of the tapered roller bearings can be atributed to the lack of proper tools and attention to detail. Most I see have obvious damage to the hub due to poor workmanship.

The ball bearings used in Impreza (Ex. WRX) and Forester, were just junk.

[smurfmiata93]

I replaced one of the rear bearings on my 99 OBW a little over a year ago. I picked up a hub tamer kit on Ebay for $150 and got a few other tool pieces from Kent Moore. Got Timken bearings from Autozone and the seals from Subaru. The bearings had a little grease in them so I just repacked them with synthetic bearing grease. Followed the Subaru procedure (can be found on the old website). So far no problems.

[88HatchMonster]

UPDATE: I have new info on this subject.

If you drive your Impreza throught the winter in a rust/salt-belt state, you MUST replace your rear axle with your wheel bearing and seals.

A rusty outer CV cup will never make a proper seal against the seals in the spindle, and water and crud WILL find it's way inside the wheel bearing.

This info comes from the owner/operator of a large independent subie shop in central Vermont. I brought up the subject of repetitive rear wheel bearing failure and he instantly asked the question, "did you install new rear axles with the bearings?" He said that a set of new bearings can get destroyed in as little as three weeks if you don't replace the axle as well. I, for one, believe him. And if you're wondering if he was trying to convince me to have work done there or something, he wasn't. This was just common knowledge to him.

[frag]

UPDATE: I have new info on this subject.

If you drive your Impreza throught the winter in a rust/salt-belt state, you MUST replace your rear axle with your wheel bearing and seals.

A rusty outer CV cup will never make a proper seal against the seals in the spindle, and water and crud WILL find it's way inside the wheel bearing.

This info comes from the owner/operator of a large independent subie shop in central Vermont. I brought up the subject of repetitive rear wheel bearing failure and he instantly asked the question, "did you install new rear axles with the bearings?" He said that a set of new bearings can get destroyed in as little as three weeks if you don't replace the axle as well. I, for one, believe him. And if you're wondering if he was trying to convince me to have work done there or something, he wasn't. This was just common knowledge to him.

I have no difficulty believing that. When I replaced my front half-axles, I replaced the inner bearing seal as well and to this day keep asking myself how a dry seal like that can survive having even a new shaft outer cv cup rotating inside it for thousands of miles. I thought about packing the inside of the seal with grease but decided against it thinking that, if hot grease got past the seal and got onto the cup, it would attract sand and grind down the seal in no time.
Anyone knows something specific about the solution of this "problem" ?

[WAWalker]

The reason for replacing the axles along with the wheel bearings, when car is driven in a "rust belt", is that the seal surface on the axle gets rusty and pitted.

As long as your axles have the dust sheild on them you don't have to worry about dirt eating the seals. Unfortunetly the axle remanufactures are getting lazy and not putting dust sheilds on the remaned units. From what I've seen most shops replaceing axles with remans that don't have dust sheilds are to lazy to take the dust sheild from the old axle and install on the replacment.

[The Dude]

Subaru seems to have more wheel bearing failures than some other manufacturers. Is the problem with a rusty outer CV cup unique to Subaru axles? Subaru likes to pitch their cars as being suited for heavy service. How do other manufacturers deal with the rusty CV cup problem?

Great post on the rusty CV cup, BTW!!

[1 Lucky Texan]

anybody got a diagram of this? Or can whip up and post a cutaway drawing?

just wondering

Carl

[88HatchMonster]

Ya know, I really think we're getting somewhere here.

All of my EA81 subarus have dust sheilds on the CV and DOJ cups that cover the seal area. The bearings do last forever.

My 98 OBS has no kind of dust shield on the outer CVs in the back.

Do some other new-gen cars actually have dust shields on the outer CVs?

If I do end up replacing my axles (and bearings again) I may figure out some way of shrouding the seal area from the majority of dust and dirt. I will also likely do a careful spray-gun coat of rust-bullet on the outer CV cup.

[cookie]

Have you guys every taken one to a real bearing shop? There are seals available that run on thier own sealed suface and of course bearings that have thier own seals. There are also surfaces that can be applied to an axle that would give you a new sealing area. I forget the brand names since it has been so long.
On Greyhound busses we often ran 3,000,000 miles or more so seals and sufaces have to be replaced regularly.
Just to give you an idea BMW rarely has this problem and they run a self contained sealed bearing. It is more expensive when you have to replace it as they sell them hub and all if I recall.

[WAWalker]

Ya know, I really think we're getting somewhere here.

All of my EA81 subarus have dust sheilds on the CV and DOJ cups that cover the seal area. The bearings do last forever.

My 98 OBS has no kind of dust shield on the outer CVs in the back.

Do some other new-gen cars actually have dust shields on the outer CVs?

If I do end up replacing my axles (and bearings again) I may figure out some way of shrouding the seal area from the majority of dust and dirt. I will also likely do a careful spray-gun coat of rust-bullet on the outer CV cup.

I was refuring to the front axles. Legacy, Imp, and Forester REAR axles have no dust sheild on the outboard CV joint.

The front wheel bearings only have one inner seal, an oil seal, and then the dust sheild on the axle to keep dirt out.

The rear wheel bearing has two inner seals, an oil seal and a dust seal, no dust sheild on axle.

Living in Montana I don't have to deal with a lot of rusty cars, but have had the misfourtion from time to time, as this is a collage town. So I have seen the rusty rear CV joint that you speek of. Another recomendation would be to pack the area between the oil seal and the dust seal with water proof grease.

[cookie]

I think the only reason I have not had the typical Forester wheel bearing problem is that my car does not live in the salt. The more shielding the better for your cars in the salt belt.
I'm glad you guys have made me aware that remaufactured axles may not have the shields and may not be the best quality for the day when my boots finally crack.