Steel upright front wheel bearing replacement

When you hit a pothole and it sounds expensive..
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Ronin
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Joined: Wed Sep 06, 2023 4:57 pm

Steel upright front wheel bearing replacement

Post by Ronin »

A few pics from my well spent sunday afternoon.

One of the benefits of having steel uprights is that the bearing is a 'screw in' type rather then press fit so I've been able to do it without a press or removing the whole upright.

How can you tell your wheel bearing is bad?
if you start to hear a loud noise and a faint vibration from the steering wheel, you zig zag the car and the noise quietens when turning left, its the left front or rear bearing, and when turning right, its the right front or rear bearing. You can narrow it down by jacking the car up and just spinning the wheel and giving it a bit of a wiggle.

The basic sequence for replacement is:
Remove the center cap and loosen the main shaft bolt and wheel nuts:
main bolt.jpg
remove the 2x 21mm caliper bolts and zip tie it out of the way and remove the drive shaft:
driveshaft out.jpg
Loosen up the 4 bolts holding the bearing to the upright and hammer the bearing out of the way:
1 (8).jpg
WhatsApp Image 2024-03-05 at 18.57.24_9c08ea29.jpg
If your CV boot is bad, now its also a good time to replace it:
1 (9).jpg
New Vs old bearing, notice how it has a hole for the disc retaining bolt, the original audi hubs dont:
1 (4).jpg
I cleaned up the upright with a drill and a wire brush attachment, and coated it and the new bearing with some grease to ease the install and stop the corrosion.

New bearing in:
1 (10).jpg
And now the re-assembly begins.

Sadly the holes for disc retaining bolts did not match..
1 (5).jpg
1 (7).jpg
And now just like the famous phrase goes.. "Installation is the reverse of removal"
Here's some useful info anyway
2x 21mm Caliper bolts should be done up to 120mm
4x bearing bolts are 80nm + 90 degrees
main driveshaft bolt is 190nm + 180 degrees, I've been only able to get around 90 degrees before the bar started to bend
SKF wheel bearing part number is VKBA6546F, it cost me £102.64 on autodoc
Outer Lobro CV boot part number is 306353 and cost me £8.45
Torque wrenches, long extensions and quality spline and hex sockets are a must.
my cheap 21mm socket broke when trying to undo the caliper bolts:
13413413413.png
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Strummagnet
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Joined: Wed Sep 27, 2023 7:14 pm

Re: Steel upright front wheel bearing replacement

Post by Strummagnet »

I only just got to 80nm when refitting the bearing bolts - the extra 90degs was just not going to happen without the car moving or my bench shifting from the wall. All seems ok though through various speed tests. :D
______________
Paul - Gosport
Audi S8 FE - Red Leather - Barn Find fixed by MJ
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Ronin
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Joined: Wed Sep 06, 2023 4:57 pm

Re: Steel upright front wheel bearing replacement

Post by Ronin »

How did your bearing fail? mine started to make a noise somewhere in Belgium on the return leg from Poland
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Strummagnet
Posts: 20
Joined: Wed Sep 27, 2023 7:14 pm

Re: Steel upright front wheel bearing replacement

Post by Strummagnet »

The classic bearing noise getting louder. I was convinced it was nearside rear, nope. Nearside front, nope. Offside rear, nope. Offside front, yes. So ended up replacing all bearings. I kept the original hubs. All bearings Miele.

As an aside, when I noticed the noise MJ correctly called offside front. I wasnt convinced. I was wrong. :shock:
______________
Paul - Gosport
Audi S8 FE - Red Leather - Barn Find fixed by MJ
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