Topic: Mazda3 Wheel Bearing replacement

[curls]

Has anyone here done a wheel bearing/hub assembly replacement on a Mazda3 before? My mother-in-law's 3 needs the RF bearing replaced (the LF was replaced at the dealership a few months ago, and now the RF one is dying as well).
From my contact at a Mazda dealer, I know the replacement part is a hub and bearing assembly, so I shouldn't need a shop press. I will be changing all 4 rotors and all brake pads next week on the same car, so I might as well do the wheel bearing while that corner is disassembled.

How difficult is this? More specifically, will I need any special service tools? I have all the required sockets, an impact wrench if needed, torque wrenches, etc... but no ball joint popper ("pickle fork"), no shop press, etc. What is required besides normal tools?

Thanks

[curls]

To add to this a bit, here's the page from the shop service manual for this job: http://www.thaimazda3.com/svmanual/esicont/en/srvc/html/B3E031104060W02.html

I am concerned about the SST's used in the 2nd-last and 3rd-last pics.  It appears to still use a hydraulic press (??) to push the hub assembly in and out of the knuckle.  Can anyone confirm?

[maritime_storm]

The front bearings are a hub assembly, but are not a bolt-on hub assembly, but a press-in hub assembly. You will also, almost guaranteed, to need to replace  the front ABS sensors(if equipped, most are) as they almost always break when you try to remove them, and you HAVE to remove them to get the bearing out. You HAVE to remove the spindle to press the hub assembly out and you should have the car aligned afterwards. The dealer won't quote me a front bearing for these cars now without pricing out a sensor, only once have we not needed it. The front bearings on these cars seem to hold up about as well as those on a Cavalier, unfortunately for the moment they are still a dealer item and not a cheap one at that. Double check that it actually needs the rear before ordering it, I don't recall us changing a rear one on these cars as of yet.

[curls]

Thanks Maritime_storm.

I have a stethoscope to check which bearing is growling, as the LF one was replaced in January but it seems that same one is bad again.  I would assume so, anyhow, based on it getting louder when we turn right (weight to the left bearing).

I can get the bearing (and most items) at a better price than most since I have a friend that works for Mazda parts.   Still though, $165 for the bearing isn't cheap, you're right.  I am curious to know how much the ABS sensor is... they aren't listed on autopartsway.ca (although the OEM hub/bearing assembly is, for the same price I can get it).

[ArticSteve]

You can get a TIMKEN OE replacement front hub assembly from thepartsbin.com for $63.70 and a ABS sensor for $26.95 USD.  They ship to Canada.

Autopartsway show the actual wheel bearing for $54.84.  Since you are gonna have a machine shop do the work then you could go with just the bearing, but I'd rather have less complication and use the hub.  But I would not be spending $165. on a Mazda unit that is for sure which are obviously crap.

If you have a selection of huge sockets and are fearless with a sledge hammer then you can fore go the press.  I've only done that once successfully, but won't do it again.

[curls]

Mission accomplished

After putting up a chair rail in my baby-to-be's room this morning, I set out to tackle the 900# gorilla, aka the wheel bearing of the Mazda3 in my garage.  It took a bit to get some seized bolts off, even with 350 ft-lbs of impact wrench on it, but once it was off I took the knuckle and new hub assembly to the nearest independent garage, slipped the guy $50 and watched him work some magic with the press and proper adapters for this bearing and hub.  I asked a few questions about reassembly of the tie-rod end and lower ball joint (stuff I haven't tackled before) and was on my way.  45 minutes later the car was back together, good as new!

There was play in the old bearing when grabbing 12 and 6 on the tire and wiggling it.  With the new bearing (front right this time) there was NONE. 

Now my back is killing me, and my ankles and knees.  Time to find a decent garage stool since I don't have room for a lift.

[dr_spock]

Good work.      I sometimes use kneepads or put down cardboard so I don't have to kneel on concrete. 

[curls]

Good work.      I sometimes use kneepads or put down cardboard so I don't have to kneel on concrete. 

I typically don't kneel (harder to get up from that, LOL).  I usually squat down and/or stretch one leg out like a few baseball catchers do.  I'd still prefer a stool!

[blur911]

I bought a foam pad made for just that purpose from Princess Auto.  Works great, as does the short stool I also have for such occasions.

[maritime_storm]

Was he able to get the ABS sensor out without breaking it?

[curls]

The service manual order of removal says to remove the ABS sensor before any major components (ie: once the rotor is off, the ABS sensor is next).  The little reverse-torx screw was able to be removed with a 3/16" socket just fine, but removing the plastic sensor itself at this time resulted in it being broken.  Stupid, stupid design.  Luckily I took your advice and had bought the replacement sensor with the bearing/hub assembly, so it was no big deal.

I later realized that the sensor could have stayed on there until I brought the knuckle in to the garage for the press work, but too little, too late.

Oh well, it's done. Test-drive today since I was too busy to take it out yesterday.

[maritime_storm]

It reminds one of a GM through block style Cranksensor. The sensor has an o-ring on it near it's end aand rust builds up behind it, which results in it being damn near impossibleto remove without breaking.

[elijah]

The front bearings are a hub assembly, but are not a bolt-on hub assembly, but a press-in hub assembly. You will also, almost guaranteed, to need to replace  the front ABS sensors(if equipped, most are) as they almost always break when you try to remove them, and you HAVE to remove them to get the bearing out. You HAVE to remove the spindle to press the wheel hub assembly out and you should have the car aligned afterwards. The dealer won't quote me a front bearing for these cars now without pricing out a sensor, only once have we not needed it. The front bearings on these cars seem to hold up about as well as those on a Cavalier, unfortunately for the moment they are still a dealer item and not a cheap one at that. Double check that it actually needs the rear before ordering it, I don't recall us changing a rear one on these cars as of yet.

My friend has is also planning to replaced his wheel bearing and he is also having problem with the hub assembly but thanks to maritime to this great details on how to do it. This is really a great help to him.

[kbpetrov]

Here is what I did...

[blur911]

Here is what I did...

Nice diagrams.  Coincidentally a friend at work borrowed some tools last week to do the bearing on his Mazda 3

[kbpetrov]

I forgot to mention that if your bearing is with magnetic strip (for the ABS) is should face down on my diagram, toward the engine.
By the way all of the exercise could be done without removing the ABS sensor.