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View Full Version : Front wheel bearing, to diy or not to diy?



Nevalite
11-24-2012, 05:03 PM
Hey guys,

I need to replace my front right wheel bearing and I am considering doing it myself, I have access to a hydraulic press at school (not sure how many tons...)

I have no problem removing the knuckle assembly from the car, the only part I would need guidance on is the pressing out/in of the bearing. The DIY I read used a hub tamer and not a press...

How exactly do I press out and in the bearing? From what I understand the bearing can only be pressed out from inside to outside? I was considering machining myself a circular plate the size of the bearing to help myself while using the press?

I also read that this can be done with the knuckle on the car and just hammer in/hammer out, sounded a bit risky to me.

What do you all think?

Bear in mind that I live in Quebec and the bearing is probably nice and corroded in place.

nynoah
11-24-2012, 05:17 PM
It cost me 30 dollars to have a shop press it out.

steven_1104235
11-24-2012, 06:15 PM
I haven't done it on this car, but I have pressed many other things out including bearings. You just need to find something sturdy(Socket,pipe, anything metal) that is round and smaller than the hub opening to press things out. There are bearing adapter kits that cover most popular size bearings, but most of the time you can find something and improvise. If you can machine one to fit the new bearing then you're all set. Putting it back in you have to be more careful and make sure the entire bearing is being pushed, not just the middle. If the outside edges aren't being pushed as well, the bearing can be damaged/blown apart. Again, with the right size adapter you'll be all set. I know people who have managed to hammer in/out bearings, but if you have access to a press just do it that way, its the correct way and you have a much greater chance of it being done right.
As far as setting the hub up in the press:
1) Stack wood/metal/solid objects to prop both sides of knuckle up enough for the old bearing to pop out front.
2) Place knuckle back side up, level side to side, towards hydraulic press shaft(so wheel side is facing towards floor)
3) Place adapter on top of bearing
4) Actuate press until shaft presses down on bearing adapter, continue until it pushes the bearing out the front, wheel side of knuckle(Bottom side towards floor while in press)
My excellent MS Paint Picture describing such lol:
http://i957.photobucket.com/albums/ae54/steven_1104235/pressbefore.png

Install:
1) Clean out knuckle bore
2) Apply hi-temp wheel bearing type grease to knuckle bore and exterior of bearing
3) Put Knuckle in press with wheel side facing up(opposite of bearing removal), solid object not needed underneath this time unless needed to make knuckle stand straight
4) Put bearing on top of knuckle bore
5) Place bearing adapter on top of bearing
6) Actuate press until bearing is fully seated in knuckle bore, i.e. resting on lip on bottom/back of knuckle bore.
Picture:
http://i957.photobucket.com/albums/ae54/steven_1104235/pressafter-1.jpg

That's just a universal description of pressing bearings in/out, at least how I've always done it. Once again, I have never done it on this specific vehicle before.

nate53
11-24-2012, 06:26 PM
I love the drawings! Just fyi on these cars everytime you press the hub out of the bearing the bearing comes apart. So you will have to have a hub tamer or air hammer to get the race off of the hub so you can press it back into the new bearing.

legbuh
11-24-2012, 06:31 PM
Bfh and socket of the right size..... Bam! :)

Nevalite
11-24-2012, 06:41 PM
Thank you for the drawings and the instructions steven, that is more or less what I had planned in my mind.

The bit that confuses me is what nate53 mentioned about "pressing the hub out of the bearing" and getting the race off the hub...

Could someone elaborate on this?

Thanks

mholme
11-24-2012, 06:42 PM
http://www.audiworld.com/tech/wheel44.shtml B5 S4 but same process. I was only able to do one of 4 bearings with a cheap Harbor Freight 12 ton press. I have a BMW shop a block away from my house so I just walked the uprights there and had them do the press work. If you end up having an indy shop do it, make sure they know the bearing is stepped and goes in only one way.

Nevalite
11-24-2012, 06:53 PM
Very nice article, just what I needed thank you. Seeing the size of that press, I think the one we have in our shop is also a 12 ton, hopefully it can do it.

Just to be sure, what size of bearing do I need for my car? ATW Quattro.

The site I usually buy from is listing a 75x37mm, is that correct?

Thanks

mholme
11-24-2012, 06:59 PM
75mm. 4B0 498 625.