What causes this then?

[zcacogp]

Chaps,

History: My (superior []) S2 hasn't been used much of late, as my work situation has changed. However I've done around 600 miles in it in the last week, and after around 400 of them noticed this:

It's in good mechanical order, and I am assuming this is wheel bearing related - but I haven't done anything with them recently. In fact, I have never done anything with them - I have done 60k miles in the car since I bought it, so they are at least that old and probably a chunk older (I can't remember the history but don't think they were changed before I bought it.)

So ... what causes this pattern of stuff to come out of the centre of them? Time to take the bearing apart and have a look at what is going on in there? Time for a new bearing? (Not too difficult, non?) If so, I'll do both sides at the same time. I seem to recall that there is slight play in both front wheel bearings, and has been for a while; the MOT chap has called my attention to it, but it's not bad enough to warrant even a formal 'warning' at MOT, let alone a fail.

Suggestions welcome. And I'll post more when I dismantle it.

(Sorry about the poor photo - it was driven in the rain yesterday and some of the traces have washed off. It was more obvious before!)


Oli.

 

[andy watson]

Hi Oli,

I assume that it is not just general dirt and brake dust etc running out with all this lovely wet stuff falling out of the sky causing hose pipe bans?

 

[zcacogp]

Andy,

Don't think so. Partially because it seems to be coming from the centre of the wheel, partially because it happened after doing a reasonable distance (at speed) in the dry. Only the last couple of hundred miles were in the wet, and that caused the traces to get less noticeable.


Oli.

 

[colin944]

Only thing I can suggest is pull the wheel off and have a look.It could be just cack comming out from the bearing cover(cap thing) or maybe the bearings are on the way out.

 

[Mike_Pollock]

I would guess wheel bearing.
Not too sure if S2 have different ones but earlier ones are adjustable.
They have a push on cap which should keep the greasy stuff in, so I'm surprised it is coming out like that, which in turn suggests that it has got very hot, or the cap has fallen off. Or S2s have a completely different arrangement.

 

[Buddy]

As Mike says, Check the bearing play and rotation ( in case of noises ) when jacked up and maybe adjust as necessary if it's not been touched in 60K then it possibly needs adjustment.

 

[colin944]

The wheel bearings are practically the same.big domed cap with all the gubbins in behind.they are easy to adjust with an allen key to loosen the lock bolt and then just turn the whole thing in or out.Sorry for the pish description as I can't remember the name for the nut thing.

 

[Alpine]

I'd put it down to brake dust and forget about it .......

my wheel nuts are black, whereas yours look silver/grey. Could it be the black coating coming off your nuts?

 

[hotblack944]

ORIGINAL: Alpine
Could it be the black coating coming off your nuts?

[][][]

 

[zcacogp]

Update on this - I finally found the time to take the hub apart and see what was going on in there. I knew that the wheel bearings had had a slight amount of play on them at the last couple of MOT's so it was due to be looked-at, although there were no signs of anything amiss.

As described, the wheel bearing arrangement is simple. I had bought a couple of replacements as a back-up, but they proved un-necessary (I think). I took the grease cap off to discover the grease looked fine. Loosened the centre nut-thing (what's the proper name for this?) and removed it, removed the bearing and wiped all the grease out. All looked fine so I cleaned everything, re-packed it with some Castrol LM and re-assembled, adjusting it in line with the instructions on Clarks Garage (i.e. so that the tabbed washer behind the nut-thing can be just about moved around with a small screwdriver, but not easily.)

I also did the other side, with exactly the same result.

I've driven it 'round the block to make sure that all is well, and there seems to be no difference to anything. So I guess I now need to wait and see whether the fresh LM is thrown out as well. Although, having said that, neither side seemed short on grease when I took the caps off so maybe the black traces on the wheel faces were something other than bearing grease - as Andy Watson and Alpine suggested.

So ... all a bit inconclusive. I'll update this if anything else develops.

Particular thanks to ChrisG on here for calling me up to offer advice and help after I first posted this thread. Thanks Chris - and sorry I didn't get to talk to you!


Oli.

 

[Mike_Pollock]

Sounds like a good job.

Castlated nut!

 

[zcacogp]

Mike,

Thanks.

No - this is a castallated nut:

... so called because it looks like a castle, with castellations around the top.


Oli.

 

[Hairyarse]

Just a 'nut' then?

 

[colin944]

No I would say it was more of a clamp type thing.

 

[George Elliott]

assuming all this refers to the front axle, its a unique split nut with an M6 Cap Screw to lock it. (infinitely variable as opposed to the 6 position castellated job such as would be on a motorbike rear spindle)

the infinite adjustment is required as a bearing should have maybe a couple of thou (0.002") clearance which cannot be achieved with a castellated nut with 60 degree increments in position, (think of a 1.2mm thread pitch divided by 6 positions, giving 0.2mm adjustment increments - 0.008")

Oli, is it possible the locating boss on the hub has been greased to aid wheel removal? I have seen similar symptoms from that.

George
944t

 

[Hairyarse]

ORIGINAL: colin944

No I would say it was more of a clamp type thing.

Nail on head, checked parts catalogue (as bored!) and its a 'clamping nut' at the front, and a nut at the back []

 

[DavidL]

Oli,
It happens becasue you can't go fast enough! []



Sorry, not being much help! Nothing constructive to add but hope you get to the bottom of it.

 

[Mike_Pollock]

Sorry chaps - thinking about the rears[][]

 

[peanut]

ORIGINAL: Alpine

Could it be the black coating coming off your nuts?

if the black coating is coming off your nuts Mr bedroomslippers ..you could be in big trouble [][][]

You don't think it could just be dirty water coming out, that had seeped under the bearing cover during this recent monsoon do you ?

 

[zcacogp]

ORIGINAL: peanut
You don't think it could just be dirty water coming out, that had seeped under the bearing cover during this recent monsoon do you ?

I think that is possibly the most likely explanation yet - thanks Peanut. I'm not sure how the water would have got under the bearing cover (it's a pretty tight fit, and is sealed with grease all 'round) but it would certainly explain the symptoms. And the weather has been more than a little humid recently ... []

Oh, and nuts to you too! [:'(] (<<Nearest smiley I could find to one putting his tongue out at you!)


Oli.