How NOT to change a wheel bearing.

[uniberp]

When you suspect you have a bad wheel bearing: droning noise, scraping sound occurring randomly or on turns, before you jump to any conclusion:

 

CHECK the AXLE staking nut. If it comes loose, the bearing will behave as if failing. The staking nut on my 2008 is torqued to 160 ftlbs. It had come loose after a year, for some reason.

 

If I had tried that early, I might have been able to just tighten it,  saving the seals and myself a whole lot of learning. Instead, after seeing the wheel wobble, I "knew" it was a bad bearing.

 

Having been thru a couple legitimate bad/burnt bearings before, I decided I should buy the press and bearing pusher tool. The 12 ton press was more than sufficient. 

 

The 2 Youtube videos on Forester/impreza gloss over a critical point, that when you are pressing out the old inner race, you need to use the undersized tool, (65mm I believe), and although it does not fit correctly, it works. DO NOT USE THE 72MM TOOL. My excuse is that it was late Saturday night and I was tired, but the way it fit so well let me press on the casting 'way too hard, expecting the 'pop', and feeling stupid. I was just pressing on the knuckle casting. I went inside and sat down.

 

It was at this point I realized the possibility that the stake nut was just loose, and the whole thing was probably a mistake, but now I had it in pieces.

 

I heated the knuckle in the oven the next morning, when my eyes worked, and using the 65mm tool, the press slid out easily. It DOES require a press. I seriously doubt you could tap it out with a chisel.

 

I used the skf hub kit, which DOES NOT COME WITH SEALS, and got new seals, and it all went back together nicely. You need a "bearing separator" if you want to reuse your old hub. I piece of 1-5/8 id exhaust tube slotted up the side works well for setting the inner race on the hub. Don't forget the outer seal first.

 

I torqued the stake nut, went for a drive, then torqued it again and staked it. I had to take the wheel off once more to bend the scraping backing plate, after the brakes warmed up. Apparently the disc expands a few mm when hot.

 

The seals were probably damaged by the wobble, and maybe the bearing also, so ....whatever.

 

Oh yeah, 2008 Forester NA 4EAT

Edited March 7, 2017 by uniberp

[Naked Buell]

Sorry about the headache but thanks for the heads up.

[TurboRev]

That is definitely useful information.  Thank you!

[Fairtax4me]

You would have ended up changing the bearing anyway. When the axle nut comes loose the bearing gets loose and driving on it will chew up the bearing quick. Might not notice it right away but you won't get more than maybe a few thousand miles.

[GreaseMonkey03]

For what it's worth, although a press makes everything easier, you don't have to have one. If you don't have the space or money for a large press, you can use a screw type bearing tool to press the new one in. No press needed to remove the old bearing or the inner race from the hub.

Takes practice but I do it all the time. I'd be happy to do a write up next time I do one at work but I just assumed a forum like this had a write up on it somewhere.

[CNY_Dave]

Below not applicable to bolt-in bearings...

I believe there are bearings out there that swap out with the screw-type press... but I also believe I've never met one!

 

Every one I've done has had me hanging off the lever on my 20T hydraulic press.

 

Even if so, getting the snap ring out with the hub in place on the car I will say right now I would never have been able to do on any of the one's I've done. Way to crudded and rusted into place.

[GreaseMonkey03]

I have had the great misfortune of having to do bearings with no press available. I also do side work away from the shop I work in and have been forced to learn alternative methods. I agree that doing it while still in the car is nearly impossible and although I have done a couple while still on the car, I wouldn't do it again if I didn't have to. At least one time it was a rear Subaru bearing whose bolts were so sized up that I couldn't/wouldn't dare to fully remove the knuckle. The others may not have been Subaru.

 

I also worked with an old timer that taught me the ways of the bearing. Now, don't care how seized it is, I'll have it out without breaking a sweat.

 

As promised, I will take the time to do as thorough a write up as I can and even give alternate ways of doing the same thing.

 

I've seen guys hang off the press lever. I never wanted to to be honest, and after seeing a few pop under those conditions and having once been hit with shrapnel from across the shop, it's not a method I recommend. There's a much easier, much safer way.

 

Do not fear the bearing. Become one with the bearing. Beeeeee the bearing. Ooommmmmm

Edited March 7, 2017 by GreaseMonkey03

[Fairtax4me]

I use a hub grappler on most. Works great with the impact wrench and you can turn it with a breaker bar easy enough if you don't have shop air available.

Haven't had one yet that wouldn't come out on the car with the hub grappler, but I don't work in the severe rust belt, so most cars here have only mild rust.

[uniberp]

The rear "longbolt" type knuckle would be a reason to have a way of doing it on the car.

That bolt may make removal of the knuckle impossible.

A screw type press might be the trick there. Getting it square enough to pop would be the trick, I can see.

Tiighten it, tap opposite with a hammer, hit to align until it starts to move.

 

Torch heat doesn't seem to help much, too localized and constrained by colder regions. Maybe longer term electric heater fan might. 

[GreaseMonkey03]

I hate the long bolt. if you don't have a torch and a compressor, don't even try to get one out that's seized. And if you can't get all the way underneath, you'll probably destroy at least one control arm bushing trying to get it hot enough.

 

To work around this issue and still be able to use a press, I disconnect the inner bolts and leave the control arms attached. Mark the bolts to try and keep your alignment it just get an alignment done afterwards.

 

I don't like using a torch on anything that holds a bearing. I'm always concerned I'll warp it.

 

Getting a bearing to pop is the most important part, and I never ever ever pop a bearing with a press of any type. The best method for popping a bearing is impact and/or vibration. Bearings create a large friction surface that pressure alone does not suffice to overcome.

 

On a rear, for example, if it needs to be done on the car. after removing hub and circlip, reattach the spindle. using the proper sized die, and a bfh or an air hammer, beat the hell out of it like it owes you money until you see a slight gap between the bearing and its seat. It really doesn't take more than half a dozen or so hits on most bearings. THEN, use the screw press or any other press, tap as needed as pressure increases.

Edited March 9, 2017 by GreaseMonkey03

[uniberp]

More on the longbolt...

 

Here's  how you extract the longbolt. Sorry, but you have to cut the head off, and it's a special size, but I think I paid $16.
It's an old pic, but I think I remember how it was done.
1. remove strut pinch-bolts, caliper, axle nut, etc.
2. Remove "longbolt" nut.
3. HAMMER the longbolt out of the front arm and knuckle.
4. At this point you are kinda stuck, if the bolt is rusted to the inner bushing of the rear arm, and no amount of twisting or hammering will free it.
5. One way is to remove the entire arm, but that inner bolt may be rusted even more badly. The bolt is still stuck in the arm. There just is no way to  get between the bushing end and the bolt head.
6. Cut off the bolt head.
7. With that arrangement shown, a washer that just fits the bolt, an open end wrench, and a pitman arm puller.
8. This method saves the rubber bushing. With a new bolt you can just bolt it up and go.
9. Cutting the head off a hardened 16mm(?) bolt takes some doing. Sawzall 10 minutes, or a couple cutoff wheels and that nast smell.
10. It is not pretty, but it is done.