Front hub bearings

[stroprock]

I am in the process of changing my saloon's front hub bearings. The drawings I have seen of the front hub bearings show both inner and outer up against the inner faces of the hub, but when I press in the new inner bearing and add the tapered spacer, the outer bearing can't sit far enough down into the hub to be up against the step in the hub. Is there something I am missing here, or is the outer bearing meant to be further out?
The pale blue bit in the attached picture is the hub, and illustrates the step in the hub to the bearings I am trying to explain.[frame][/frame]

[philthehill]

The outer races of both inner and outer bearings should be had against the inner shoulders of the hub.
The spacer (grey tube) is what gives the clearance/pre-load on the bearings.
Have you got the bearings in the right way round as per the diagram?

[bmcecosse]

Where did you get the new bearings? Hopefully not the excessive clearance 'C3' type...often sold cheaply..

[stroprock]

Bought them from ESM (this one: http://morrisminorspares.co.uk/shop/pro ... fb9125e1ed). If you press in the rear bearing, the spacer sits higher than the outer shoulder when put in place

[bmcecosse]

'Non branded kit' - oh dear..... These are safety critical items, I would only buy well know branded items. So saying - I have never had any front hub problems in all my years of Minor motoring ! If they are C3 (look at the markings) then they will be loose when assembled and won't pass the MOT.

[stroprock]

What makes you say they are wrong? They are branded powertune. What now?

[MikeNash]

Does the spacer sit much higher? If its very little might a bit be ground off the spacer? Or more to my liking, might a large diameter "shim washer" of the right thickness be fitted to take up the clearance so that both outer races are in proper contact with the hub?
Regards, MikeN.

[Sparticus]

Hi guys I believe that the we've just sourced some new bearings, the proper face adjusted ones, at DSN. I will try and get some more details for you today, if it would be of any use?

[philthehill]

Bought them from ESM (this one: http://morrisminorspares.co.uk/shop/pro ... fb9125e1ed). If you press in the rear bearing, the spacer sits higher than the outer shoulder when put in place

A photo of how the spacer is in relation to the bearing would not go amiss as I cannot get my head round how the spacer can sit higher than the outer shoulder.
Phil

[stroprock]

Hubs at work, I will get a shot early next week

[bmcecosse]

The ESM link says they are 'unbranded' - which would have me running for the hills. You should NOT have to machine anything - or add random washers....

[stroprock]

What kit would you recommend instead?

[bmcecosse]

Buy from bearing specialists - or follow up the DSN suggestion above.

[M25VAN]

Hi guys I believe that the we've just sourced some new bearings, the proper face adjusted ones, at DSN. I will try and get some more details for you today, if it would be of any use?

Yes please Sparticus! This topic seems to come up quite a lot so some proper bearing numbers that are known to work would be a useful target.

[IslipMinor]

The basic front hub bearing numbers are 7303B and 7205B, and for the 40°angular contact and 'face adjusted' versions the numbers are:

NSK
Outer - 7303BEAT85SUN
Inner - 7205BEAT85SUN

SKF
Outer - 7303BECBP
Inner - 7205BECBP

With the significant passage of time the hubs can also become worn/damaged on the inner register faces, so even fitting the correct design and tolerance bearings does not always provide the complete answer.

The whole hub and bearing set up is a precision assembly, I would not suggest trying to adapt anything unless you know exactly what the problem is.

Stoprock, Where do you live? If anywhere near Oxford I can measure hubs, spacers etc. to make sure all is as it should be for you.

[stroprock]

No good, I am in South Somerset, bit thanks for the offer.
Regarding these angular faced bearings, where is a good place to get them from and a fair price to pay?

[bmcecosse]

That's what you should have from your supplier! If they don't fit - send them back and demand a refund. I assume your car has the normal drum brakes - not a disc brake conversion ??

[stroprock]

Had a look today, the outer bearing was fitted the other way round which explains the spacer sitting too far out conundrum, but I just want to confirm, is the inner bearing definitely meant to have the thick part of the outer race facing the hub, as my boss thinks it should go the other way?

[philthehill]

The front wheel bearings should be fitted as per the diagram in your original post.
The thrust side of each bearing should be towards the spacer (and quoting from the BMC wksp manual section K7) "The thrust side is that side which carries the bearing part number" (if fitting original equipment (OE) parts).

[IslipMinor]

The thrust sides of the bearings are shown in the top 2 bearings in the picture below and these sides must face the inside hub faces, the spacer and each other.
[frame][/frame]
The thinner outer ring of the outer race of each bearing, shown in the bottom 2 bearings, faces the outside of the hub, away from the spacer and away from each other.