A3 8P front NS wheel bearing replacement

[guysy]

Hi,

I've recently been prepping for MOT, front discs/pads, front drop links have been changed, I definitely have some NS bearing noise at about 30mph so I know the bearing will need to be replaced at some point but Im not sure its so bad.

The wheel rocks about 1mm from left to right on the wheel test, but not top to bottom, so Im going to try just replacing the track rod ends this sunday and see if it improves.

That aside I will replace the bearing hub.

Things I know that obviously need removing off the top of my head: Caliper, caliper carrier, disc (may have forgotten some)

In one video they removed the bottom ball joint and the track rod end, then knocked the driveshaft back. In another video he managed just to remove the 4 spline bolts without doing the rest and had the hub off very quickly, is this possible of does the CV gaitor get in the way?

Thanks.

 

[Nessy]

I’ve just done this job on my car although I had the complete strut out as I was also changing the shock absorbers & springs....
If you do end up changing bearings I would recommend that you do both bearings at the same time.
In my case , one of the bearings was solidly rusted into position and only came loose after drifting it out with some suitably sized sockets and using blocks of wood as support....I don’t know how I would have managed had the strut still been in situ!
The other side the bearing easily tapped out after hitting all 4 loosened fasteners in a radial pattern.
Whichever way you try it, be prepared for rust to have taken its hold, and you’re going to need to remove the driveshaft end enough for it to have disengaged with the splined section inside the bearing?
Lastly , buy a decent brand bearing , I went for a FAG one which only cost £50 from Germany, off the shelf from the likes of ECP and GSF they cost an arm and a leg .

 

[Abi]

I paid £92 from Europarts with discount code


Sent from my iPhone using Tapatalk

 

[guysy]

Thanks for the reply mate the pics and comments really help.

Yeah I think I may have underestimated the job a bit. I penetrating oiled some of the bolt ends etc when I was doing the brakes so that may help.

Yeah I see now why the track and lower joint has to be cracked off for the driveshaft to come away from the hub.

I’m hoping to do as you said and tap the hub bolts in a circular pattern.

I’ll report back once it’s done. Cheers.

 

[Nessy]

Glad to help!
The 2 lower splined bolts (when in situ and tightened) protrude through the end of the bearing housing and consequently end up having quite rusty ends, these 2 bolts were quite difficult to remove as they put up a lot of resistance to coming out, despite the use of PlusGas!
The upper bolts were much easier to undo as the entire threaded part of the bolt lies within the bearing housing and the ends don’t become as rusty.
If you look at the last picture (of the old bearing being removed ) you can see the old bolts on the ground, the 2 top pics of course showing the new bearing in place.

 

[guysy]

Yeah, well hopefully when it comes to it I can do it with the shock and hub in place, im sure it will be a right pain in the **** though.

In terms of tightening the hub nut back up im a bit lost, is it a certain nm to be torqued then im reading its slackened half a turn then back up to another setting?

Another said 200Nm then 180-degrees after?

Thanks

 

[Nessy]

I did quite a bit of research about the front hub bolt, confusion has arisen as there was originally a 27mm hex head bolt (as my car was from the factory and some suppliers eg GKN still supply with cv joints ) , then a 12 point 24 mm bolt with ribbing under the flange head (with much lower torque) and now a 12 point with no ribbing.
If bolt has no ribbing under the head everyone now agrees it is 200 Nm and then 180 degrees.
The bolt that came with my FAG bearing was of the 12 point variety and I used a 1/2” drive socket to torque it up.
For the final tightening I used a 3/4” drive socket on a bar with a 6ft aluminium scaffolding pole for leverage and struggled to get to 180 degrees, even with my full weight on it!
Think I got to about 130 degrees and decided to call it a day,lol.

 

[guysy]

Thanks for that very useful, yeah I tried a socket to check I had the right size, mines 24mm, 12 point I assume.

Ill torque it to 200 then see If I can get any further ha!

Cheers again.

Ive seen a FAG bearing (will need to check further its definitely the right part in this link

https://www.autodoc.co.uk/fag/23312...u5u_ceeL-Y8rhi8WgB9SReiNzZkOWDWRoC-0gQAvD_BwE

Also a LUK but with no fixing kit so pointless, or this SKF

cant link but amazon uk :
SKF VKBA 3643 Wheel bearing kit

 

[Nessy]

The initial torque of 200Nm is surprisingly easy TBH, as was the first 90 degrees when the car was on the ground , it was the final 30-40 degrees ( as the bolt is stretching, like I said I never made it to 180) that’s difficult and nerve-wracking,lol.
Here’s the part number of my bearing taken from my order off the Autodoc website.....

I’m sure all the bearings, no matter what make would come with all fixing hardware though?...
I went for FAG as I know they were OEM on my previous A4 and Audi 80, I did try and see the maker of the bearings that came off the A3 but they were too rusty to identify.
Amazon UK I think have them around £55-60, ECP and GSF are the last place to buy them from as they are so expensive !
Luckily I had planned to do my bearings and so the 7 days delivery time from Autodoc in Germany wasn’t an issue.

 

[samisnake]

The luk kit has the same part number as the fag bearing so I'd guess they are just reboxing the fag part. As such I'd assume they also come with the fittings.

Id go with fag, skf, ina. The cheapest of the 3 from a reputable seller.

 

[SootySport]

Tip for large high torque nuts and bolts-
Smear lithium grease onto the mating surfaces of the nut, bolt or washer, it takes away most of the friction of the metal to metal surfaces.