Front wheel bearing centre nut tightening

[Gdcobra]

Hi, I'm just looking at replacing a front wheel bearing, as I understand it the centre bolt (which presumably sets the bearing preload rather than just attaching the drive shaft) is a stretch type which requires setting to a torque then winding the bolt a further number of degrees so I guess what I'm looking for is the torque and the number of degrees.

 

As alway as help greatly appreciated.

[Shaunieboy]

That info in definitely floating around here and out on Google. I've done the job myself but can't remember the numbers. There's 2 bolt head types to bear in mind too.

 

I'm sure someone will be along to help soon....

 

 

[Gdcobra]

Thanks Shaunieboy, found it dventually (I think), 70nm the 90* for the 12 sided bolt head. Apperently the 6 sided bolt head is 200nm the 180*. Which I think is technically known as 'kin tight.

 

Just for anyone else looking for this info, it seems the four bolts which hold the bearing in place are also 70nm + 90* and need a 12mm spline or triple square adaptor.

Also worth noting that the lower bolts are sink deeper than the upper ones so the thread protrudes and the ravages of time and salty road grime mean the bolts will probably be rusty on the exposed threads and need a bit of care to extract.  Care and WD40 help out here but it can be messy.

 

[chimaera]

Service Manual says:

Quote

12 sided bolt with serration: 70 Nm + 90°

12 sided bolt without serration: 200 Nm + 180°

For either type it says the vehicle must not be standing on its wheels while tightening.

[Gdcobra]

2 hours ago, chimaera said:

Service Manual says:

For either type it says the vehicle must not be standing on its wheels while tightening.

Interesting, what is the "serration" referring to.

[chimaera]

12 minutes ago, Gdcobra said:

Interesting, what is the "serration" referring to.

That I don't know. That's the wording from the manual. There's probably a PR code for it somewhere that a dealer can check against.

[Gdcobra]

https://workshop-manuals.com/skoda/octavia-mk2/axles_steering/front_suspension_drive_shafts/the_wheel_bearing/removing_and_installing_the_wheel_hub_with_wheel_bearing/

 

This is what I was going from, I know that's an Octy but as I understand it the assembly is very similar.

Guess I need to dig a bit deeper.

[Breezy_Pete]

Serration refers to the texture (serrated or smooth) of the underside of the bolt head, I think.

[jafo]

[Gdcobra]

My bolt has no serrations so it looks like it needs the big torque, that's nearly twice as high as my torque wrench goes! And then another 180* on top, seems a bit OTT to me.  You'd think it was holding a battleship down!

[Gdcobra]

Had a go at this at the weekend.  The underside of the new bolt is not serrated so should be the 200NM +180°, I managed to get the torque but no way was I going to get that extra 180°.  Managed about 45° that was with an extension on my breaker bar, maybe if I'd had a 10' scaf' pole handy I'd have had a chance, suspect something would have broken first though.

Although the original bolt was serrated this was not very tight, don't think it was even the 70nm.

Anyway, I can't see it going anywhere.