How to determine correct wheel bearing size

[malt56]

Hi - looks like I need to replace wheel bearing to resolve my ABS issue - there are 2 options of bearing which have different diameters :- outer 137 vs 136 & inner 32 vs 30 mm - I measured circumference of the bearing and it appears to be related to the 137/32 combination - short of removing the bearing , is there any way to verify which version I have - any online look ups which will detail correct size based on VIN and/or REG plate ?

[malt56]

- Car is an audi A3 8PA 1.6 tdi 77kW - listed as a 2010 - date of first registration /Registered in UK 28/12/2009 - SB59UCL /WAUZZZ8P2AA100175 -27% discount from ******* - so may have to take a punt in next 3 hours to get the 32mm version to secure the discount.

[Crasher]

Painful one, using your VIN in FI Suggestion it can have either a 30 or 32mm inner bore wheel bearing, you have to take the old one off and measure the location.

[malt56]

Started to clean up the edge of the bearing - there are stamped numbers/letters on there, however even after a lot of de-rusting - I noted at least a 30 stamped on it /VW + Audi logo + some letters/numbers - however not convinced this 30 relates to the bore - so going to remove the bearing tomorrow and physically measure it

[Crasher]

Deploy the stick of truth...

[malt56]

Another quick question - according to an ******* video - the bearing should be torqued to 155Nm , My Haynes manual lists 2 tightening Phases :
Phase 1 - Torque to 180Nm
Phase 2 - Overtighten by 180 degrees - ie an extra half turn

Seems a big discrepancy - which instruction should I follow ?

[VAG-Abound]

I measured circumference of the bearing ...

My tip for getting the circumference of something reasonably accurately is to put a slip of paper about 10% too long around or inside it, with a square cut edge being the "top" wrap. Get it snug and stroke a pencil a few times from the top wrap onto the lower one so your marks cross the join. Then remove, lay flat ans measure to the edge of the marks. You can get about 0.5mm accuracy by eye on the linear measurement, and by the time you do divide by pi you have 0.25mm or so.

[VAG-Abound]

The single bolt through the middle? ETKA says torque up with wheel off ground and helper pressing brake pedal, then lower and do additional degrees. Depending on the bolt type:

• Hex bolt: 200Nm + 180 degrees
• Triple square with smooth underface: Same
• Triple square with ribbed underface: 70Nm + 90 degrees

[malt56]

i tried something similar - wrapped a piece of string around the circumference and then measured, however this led me believe that I had the 137/32 type - on checking the edge of the bearing - there is a prominent 30 stamped . I wondered what ETKA was and found out its a web site which list VAG parts - it quotes that 2 types of bearing BUT they depend on which brake option is selected - on checking the build options sticker in my car , I have a 1KD listed which from ETKA appears to point towards the 136/30mm as being the correct bearing to be installed - Once removed I will confirm physically

[malt56]

Just as well I did not go with my string approach . Finally got the bearing off and measured - it is a 30mm bore !! Parts ordered