Wheel bearing disintegrates - F800

OK, thanks. I have put in quite a bit too much grease, should be around .116 fl oz. (apparently), according to this BelRay site:
http://www.belray.com/bearing-failure-due-over-lubrication
I'll probably just continue and monitor the bearing, given that it is a press fit and I'd destroy the bearings anyway in order to remove them and de-grease. CRAP, quite a few $ and lots of time involved but thanks for the education on greasing.
Greg

It never seases to amaiz me why ametures think they know more about how much grease a bearing needs than manufactures that have been making bearings for decades in all sorts of applications

Well, 2 things come to mind, one is your cheap shot and the other the manufacturing source of the bearings, both of which are apparently seeking the quality-level bottom.

oh snap.

Interested to know because i just cant remember, is the side that was dry and failed the spacer side or the side that the grease seal runs on the larger dia part of the axle ?

If its the spacer side that failed i’ll almost bet you find a groove on the surface of the spacer tgat the grease seal has made, thats what lets the shit in and grease out

Edit: partly answered my own question as i found an old photo i had, it is the spacer side that failed for you as i suspected, where i put the red arrow is where you find a groove in the alloy spacer, lets the shit in and grease out

Either buy new BMW alloy spacers which will groove again in 20,000km or buy the stainless after market ones and fix the problem for ever and reduce the bearing failure rate down to what a normal motorcycle wheel bearing failure rate is

I checked the spacer carefully and no pronounced groove just a shiny spot where the seal rides can't even feel it with my fingernail.
Far fetched but could be from being on the side toward traffic and road splash.
I know cars usually wear front suspension part more on the shoulder side of the road due to potholes being more prevalent on the shoulder.

Why is your axle nut rusted? Mine is aluminum as is the spacer.

Did you put a new grease seal in ?
If the seal was doing its job it wouldnt matter about the road splash

Never seen an alloy nut there

Example spacer, seal lip wears too

Yes both seals and bearings new and my spacer looks like a new one compared to that!
In the kit there were three seals, two of the same ID and one of a larger ID which is what my 2013 uses. I assume earlier bikes have the same size seals on each side. Perhaps that is the reason for the accelerated wear on the spacer?
My bike has the WP forks and the axle saddles are different sizes.

Check your rear Axle to see if it's bent. My local bike shop that has been helping me sort out my wife's bearing failure found a bent rear axle as they were putting it all back together.
You couldn't see the bend by looking at it, but they put the axle on a lathe to spin it, and it was then apparent it was bent. Unsure if it was bent before the bearing failure, or as a result of the bearing failure. Not even sure how you would bend the dang thing...

So here is the final update (hopefully) on my wife's bike.

After the bearing failure, we towed the bike to a shop. The mechanic diagnosed the failed rear bearing(s) and then replaced them without discovering a reason as to why bearings with 6,000 miles on them failed.
Bike was back on the road for 3 weeks or so.

Upon doing some research I found this thread and read the whole thing which took a while. The things I read and the other failures people experienced had me feeling uneasy about just replacing the bearings without understanding why they failed in such a short time frame.

We were at a point in the summer where we weren't going to be able to ride for two weeks, so I talked to a number of local bike shops that worked with machine shops that could measure the bore.
I took the rear wheel and all the components to the chosen bike shop along with a new set of bearings with green waterproof grease in them. They had the machine shop measure the bore and the report was that the crush was correct. That was not the problem.

The tube spacer (SPACER SLEEVE, INTERIOR) in the middle of the hub looked suspect and we decided to replace all of the spacers. Took 1.5 weeks to get them from BMW.
When the bike shop put the wheel back together something didn't feel right, so they looked at the axle. It looked fine, but when they put it on a lathe it was clearly bent. You can't see it by eye, but when it's spinning it's obvious.

I've ordered a new axle from BMW, but in the meantime found a good used one not too far away, had it verified straight by the bike shop and have that in the bike until the new one comes in.
Bike was down for about 3 weeks, and feel that all the components in the hub are either new or at least to spec, but didn't find a definitive problem other than the axle.

Big question is, did the bent axle cause the bearing failure or was it bent as the result of the bearing failure?

We'll probably never know...

Very good question ......which preceded the other.....and do you know the history of the bike well enough to know whether the axle was subjected to abnormal use/abuse?

my bet would be the failure bent the axle

We bought the bike used, so no, not really. The person we bought it from was a very nice guy and he did far more off road on the bike than we have done. He had even changed the countershaft sprocket to -1 tooth for better off road response, so he was serious about his off road.
It had about 12,000 miles on it when purchased. Has 26,000'ish miles today. During a tire change around 20k miles we had the bearings changed.
Normally, I take the wheel off the bike when I have the shop do the tires, and don't take the axle in with it.

The first shop after the bearing failure had the whole bike and didn't see the bent axle although it clearly was bent by this point. not visible by eye, had to spin it at speed to see the bend. It was was second shop 3 weeks later that found the bent axle luckily...

Quite likely. When the bearing failed it took about 50-100 ft to get the bike to the side of the road. The whole bike shook like it was breaking at the steering tube about once per chain rotation. At first we thought it was in the front, then realized it was in the back. I had just riveted my first chain 5 riding hours prior (dirt bikes use clips) and I wondered if I did something wrong. We had to get the bike another 100ft or so from our stopped position to a safe area once we got to the side of the road, so there was plenty of opportunity to bend the axle after the failure.

I just can't image how you would bend that thick tube of steel while it was in the bike properly supported by 3 good bearings and that inner sleeve.

I wish I had found something more definitive than the axle so I could feel more comfortable about the wheel going forward. Just not the case. I've taken every reasonable suggestion from this 83 page thread and used the knowledge to have the wheel inspected and measured for the existing parts, and added new parts (all spacers) and well lubed quality bearings.

It's all I can think to do... Ride and Pray...

Well there is definitely something wrong with the wheels or bearing for it to happen and to have a thread like this.
I myself don’t feel to comfortable repairing the BMW rear wheel in hopes that it or when it will happen again.
I think I will just order a custom wheel from Woodys wheels and call it a day.
Your suppose to be on the bike to enjoy the ride not wonder when your wheel bearings are going to go out after a few thousand miles.
Kind of bullshit that BMW doesn’t do anything about it or even recognize that it is some sort of design flaw.



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So after my wife's rear catastrophic failure in 2018, I replaced all of the bearings in both bikes. Best bearings I could find by SKF. Cleaned the grease out and put in waterproof grease (green grease) as suggested by Woody.

Had a rear brake side bearing failure again today. 2 years and probably 12,000 miles. Taking 30 days to ride the west and failure happened in yellowstone park.
NAPA had a bearing, found a garage that had some of the tools that I didn't have with me. Luckily, I felt what seemed to be the chain catching for a second at low speed. Pulled over and checked the chain and sprocket. Saw grease being pushed out of the brake side by the dust seal. Suspected the bearing right away...

Getting tired of this crap for sure...

Sorry to hear this happened to you again, particularly on a long trip. That stinks.

You mentioned in an earlier post that you had read through this entire thread looking for ideas/causes. Maybe you could tell me whether this bearing problem is also endemic on the F650GS and F700GS? Was there anything improved in the 2013 update that corrected this problem? It will save me a lot of time reading through what is quite a long thread. Thanks.

Maybe the squish is too tight. Mine had to be honed out by Woody. There is something about the design that does seem to let more crap in there than other bikes. If I still had my 800 I would just change them before a big trip.

Vark, I can only assume it is. You should compare the BMW microfiche for hub part #'s. I would bet the F700 and F800 are the same hub unit. I'm not sure about the 650.

Motoriley, I had my local bike shop take the hub to a machine shop to check the specs per Woody's thread and the hub checked out. Hers is a 2010, mine a 2012.

I can only tell you that after my wife's bearing failure, I've been super careful and repacked the bearings with marine grease, etc. per Woody's instructions...

2 days prior to my bearing failure, we were in Moab where the speed limit is 70+. Had the bearing failed then, I might not be typing this right now...

Guess it's a new set of bearings every winter for the wife (she won't part with her F800). For me, I'm probably going to buy a new wheel/hub from Woody...

I would also tell you that if you experience a rear wheel bearing failure, you need to check your axle. Put it in a lathe or drill press and see if it wobbles. If it does it's another $100+ for a new one. a wobbly axle will start the up/down movement that can make bearing fail early.

You saw the picture of my bearing, I thought I caught it early, but the axle does have a slight bend in it....