Here is a quick summary of how I replaced the front wheel bearings on my 2004 996 GT3. My car had about 22K miles on it and I could hear a constant LOUD noise coming from the front of the car.
-Turning the car had no effect on the sound.
-I could not feel any temperature difference between the good side and the bad.
Once I had the brakes off the car, the good bearing did not spin freely. The bad bearing spun like a top. BINGO.
What tools do you need? Pretty much everything, and if you donít already have everything then you should probably take your car in to have this done!. I used both the Arnnworx bearing tool and the SIR extractor kit. Ebay for the SIR kit, and Arnnworx for their tool. I also had to buy a 32mm socket for the axle nut.
Jack the car up and take the wheel off. Pop out the center cap on your wheel, put the wheel back on the car and set the car back down. Get someone to stomp on the brakes while you take a big a$$ breaker bar and the 32mm socket and back the wheel nut off.
If you have a good air compressor and impact gun you can spin this nut off. It is torqued on to 350Ft-lbs but it is doable. I have a 60gal compressor and my craftsman impact wrench spun it off. (I was surprised by the craftsman). <br/>
Once the rotor is off, unbolt the ABS sensor and zip tie the whole thing up and out of the way.
Disconnect the sway bar drop link.
I removed the flimsy shield from behind the hub. (The picture was taken after the hub was pulled). You can get to it with a 10mm wrench w/o much issue.
This is a key part of the process. Loosen the lower retaining bolt on the strut and pull the wheel hub down. This will give you the space you need to get the axle out. If you skip this you're going to look at the axle for an hour trying to figure out how to get it out.
Once the shield is out of the way and the wheel carrier pulled down on the strut, you can pull the hub with the SIR tool.
Put the additional horse shoe on the SIR tool and then just the big nut on the inside of the hub. Do not use any backing plates, just the nut. I put the tool on the wheel carrier so that it had max contact with the carrier. The tool wound up oriented with the open part of the horseshoe pointing up towards the mirror of the car.
This is a picture of the setup I used.
If you have everything setup right, the hub comes out w/o too much effort. Iíd say about 90-100ft-lbs is enough. If you find yourself looking for the breaker bar you have something screwed up. See that bend on the right bar of tool in the picture?
Once you removed the hub pull the axle out of the back of the carrier. Now itís time for the bearing. I could not figure out how to use the SIR tool to remove the bearing, so I used the Arnnworx setup as follows.
Everything comes with the tool EXCEPT for that piece of black pipe above the pen. I used it as a spacer because the back nut (silver) winds up deep into the bearing carrier and I couldnít get a wrench on it after a certain point in the removal process.
If you have a deep socket that will fit that nut then you wonít need the spacer. I didnít feel like running back out to sears.
Put a wrench on the inside and a socket on the outside and turn them. The bearing will come right out. It will break apart, but it will come out! (Inner part of the bearing still stuck to the hub).
Where's the grease? When the hub was on the car, the side with the bad bearing spun freely. The Ďgoodí side did not spin without some effort. I could not feel any rough spots nor hear any noise. The hub should not spin easily, if it does the bearing is bad.
Now that everything is apart, you have to get the race off the hub. I clamped the hub in a vice and used a flat screw driver and hammer to CAREFULLY hammer it off.
Installing the bearing is pretty easy. I kept the bearings in the fridge for a few weeks before I got around to this project.
Using the AWorx tool again, setup as follows. The big backing plate goes on the inside of the wheel carrier. Orient the bearing with the red side in towards the car. The spacers in the middle hold the bearing in place nicely. Put wrenches on both sides and turn the left nut in until the bearing is seated in the carrier. MAKE SURE IT GOES IN STRAIGHT from the start.
Reinstall the bearing retainer, the shield and then the axle. Install the hub, axle nut and tighten the whole thing down. Slide the wheel carrier back up onto the strut and reconnect the sway bar drop link. Reinstall the ABS sensor and tighten everything down. Install the rotor and caliper and pads if you removed them. Slap the wheel on, put the car back on the ground, get your brake stomp helper and torque that 32mm axle nut to 350 ft-lbs
Take it for a ride, then go have a beer and contemplate doing the rears at some point.