Tech Article Title |
Author
|
Date
|
Replacing
Rear Wheel Bearings |
Mr.
Piggie(mike01s4)
|
2004 |
Worked on an A4 1.8tq rear wheel bearing the other day.
Maybe some of ya would be interested in this if you need to do it too.....it's
not too long of a job, and I opted to pull the whole hub assembly off the car
since using a puller on there then trying to press it in would have been an
utter PITA without special tools. the only real special tool I used was a press
for putting in the new bearing. If you don't have a press, maybe you can take
the whole upright and your new bearing to a shop and they can do it for you?
Some parts/tools
- Bearing kit part number (comes with new bolt) 8D0598625A
- 10, 17, 19 mm wrenches
- 5, 8, 14 mm socketed allen wrenches
- Arbor press for putting new bearing and hub on
- Penetrating oil
- Grease for driveshaft's splines
- Heavy hammer
- Some proper size cylinders for removing/installing bearings squarely
- Very fine abrasive pad/sandpaper
I started by breaking the 14mm allen head, collar bolt, in the hub, free while
the car was on the ground. You can do it while the car is up in the air with the
wheel off, but then you need to put the parking brake on and put a lug bolt on.
After that, you can remove the two 8mm allen head bolts holding on the caliper
assembly (put parking brake on). Pull the whole brake assembly out of the way.
Remove the 3 10mm bolts for the rotor shield and take it off. Remove the ABS
sensor's 5mm head allen bolt. Spray some penetrating oil on it and with a flat
screwdriver, gently tap it in to the mating surface to make the sensor lift off.
You might want to clean the sensor up before reinstalling so it goes in smoothly
and doesn't rust to the suspension upright. After that, mark the orientation of
the lower camber bolt with it's adjustment washers. This way you probably won't
lose your alignment very much when reinstalling. Remove that lower bolt and the
upper control arm bolt, the upper stabilizer bar link bolt, and the rear
horizontal arm nut. That rear arm nut was a bit of a pain at the last threads.
You can use a clamp to keep the joint from rotating as you twist the nut off.
Now, just remove the suspension upright, and spray it up with a lot of
penetrating oil and pound out the steel hub. Chances are, you'll get the larger
I.D. part of the bearing stuck on the hub shaft. Just take a screwdriver and tap
it in between that ring and the hub and you can pry it off easily. Try not to
gouge the surface of the hub or any other surfaces as you work on it.
After that, pound out the bearing (direction for removing is towards the outside [Edited]
of the car). clean up the surface with a very fine abrasive cloth and press the
new bearing in, and watch the orientation of the bearing since it has 2
different I.D.'s due to the stepped portion of the wheel hub. Don't install it
backwards! Take some abrasive pad to the shaft of the hub, spray some oil on it
and press the hub back in and be sure to have a good backing against the other
side of the bearing so you don't accidentally pop the seal or inner race out.
That's about it. For reinstalling, put some grease on the splines of the
driveshaft. When putting the upright back on, lubricate the round discs of the
lower connection so it slips right in with a tap of the hammer. The 14mm collar
bolt needs to be torqued to around 85 ft-lbs + 180 degrees. You can judge for
yourself on that 180 degrees though ;) EEK.
Some pictures...
Close-up of bearing. note the stepped I.D.s. (facing
outside of car where hub slips into it, the large I.D. is on the outside facing
you)
Slipping the upright back in
Clamping the joint for the nut that's tough to remove
8mm allen bolts holding brake assembly on