LCGB Forums

I've got a photo to show you revealing that the god's have been with me recently. Not so long ago I was doing 8600 revs in fourth on M58 (17x46 pacemaker). I decide to check over the scooter before the Euro. Casing off, give gears a prod and plenty of wiggling and side movement going on. So I take out the gearbox, well worn by the way and find this:



Some advice please, best rear hub bearing suggestions?

Lucky boy.

Very lucky Dave

Hi,

Similar thing happened to me, I'm using at the moment a mb & scotopia bearings.... Both been in for a couple of years, no problems at all. Don't be tempted to fit a cheap Indian bearing even from a reputable dealer, the're so hit & miss quality wise & even "good" ones will be lucky to last a season.

Cheers Mark.

davet wrote:I've got a photo to show you revealing that the god's have been with me recently. Not so long ago I was doing 8600 revs in fourth on M58 (17x46 pacemaker). I decide to check over the scooter before the Euro. Casing off, give gears a prod and plenty of wiggling and side movement going on. So I take out the gearbox, well worn by the way and find this:



Some advice please, best rear hub bearing suggestions?

Very sobering photo
Glad you found this in time before disaster struck.
Is this an old original bearing ?

I found a very similar situation when asked to sort out a motor that a pal had recently had rebuilt by a lesser known dealer. The motor had done less than 400 miles since being rebuilt, including rear hub bearing, and the cage had broken up as per the photo, leaving the loose balls to move independently. The bearing was Indian but hopefully not genuine SIL.

The motor also had 2 shims under the xmas tree, causing the endplate to have seated on the xmas tree rather than seating correctly in the casing, no oil thrower washer under the front sprocket assembly and a whole host of other issues. The dealer was paid good money for his poor work, whereas I got a 'thanks mate' for putting it right! Oh well, that's mate's rates (LOL).

Adam

In my case it was an MB, always had oil level checked and changed regularly. Engine has done a few euros and I had IMHO one of the best engine builders around guiding and assisting.

A strange case indeed. I suppose there could be a number of individual and collective causes:

Poor quality batch of oil, Bad Indian layshaft, poor quality bearing etc.

Bearing wise you wouldn't expect any dealer to inspection test and check bearings. They like us place trust in the manufacturer and supplier.

You need to slow down Dave....!

Slow down Dave ? It'll never happen ,

Aye... I was being rhetorical...1

All joking aside as this is a serious safety issue...

The cage has come apart/broken up & the consequences could have been disastrous.

If you had died as a consequence, any UK Coroner would seize that bearing & all associated parts.

Unless you think that you are responsible for badly fitting (or seriously consider other components are truly likely to have caused the failure) you should be taking this issue up with MB.

Fitted correctly and always used recommended oil, which was changed regularly. The bearing's done about 15k. Will be sending it to MB to let them know. I hope it's sent back to manufacturer for a look see. I ain't blaming MB coz the problem lies somewhere else.

davet wrote:Fitted correctly and always used recommended oil, which was changed regularly. The bearing's done about 15k. Will be sending it to MB to let them know. I hope it's sent back to manufacturer for a look see. I ain't blaming MB coz the problem lies somewhere else.

The bearing failure is most likely due to a defect on the part of the supplier to MB, but presumably the choice of supplier & ultimately the quality control are down to him.

If you read his own opinions on many products, he has a lot to say about his competitors, most notably other Clubman type exhausts that he says “fall to bits!” Bizarrely, that does seem to be occurring with the Big Box system as Forum members can testify.

Personally, I’ve known other products of ‘his’ manufacture fail, such as the drive sprocket centre bolt.

Presumably he’s managed to make a good enough profit over the years, so I don’t feel much sympathy toward him.

Thankfully, it's rarely we see this situation and as alarming as it is, it can and does happen.
I've seen it, and attributed it to detritus entering the bearing from a disintegrating duplex chain. Looking at that bearing with its failed cage I'm thinking, perhaps it's more a design and application failure than a product failure. A design that could filter the lube oil before tying to use it might be all that's needed.

Top tip:- Always use magnetic drain plugs.

Warkton Tornado No.1 wrote:

davet wrote:Fitted correctly and always used recommended oil, which was changed regularly. The bearing's done about 15k. Will be sending it to MB to let them know. I hope it's sent back to manufacturer for a look see. I ain't blaming MB coz the problem lies somewhere else.

The bearing failure is most likely due to a defect on the part of the supplier to MB, but presumably the choice of supplier & ultimately the quality control are down to him.

If you read his own opinions on many products, he has a lot to say about his competitors, most notably other Clubman type exhausts that he says “fall to bits!” Bizarrely, that does seem to be occurring with the Big Box system as Forum members can testify.

Personally, I’ve known other products of ‘his’ manufacture fail, such as the drive sprocket centre bolt.

Presumably he’s managed to make a good enough profit over the years, so I don’t feel much sympathy toward him.

with you 100% on the above

Fast n Furious wrote:Thankfully, it's rarely we see this situation and as alarming as it is, it can and does happen.
I've seen it, and attributed it to detritus entering the bearing from a disintegrating duplex chain. Looking at that bearing with its failed cage I'm thinking, perhaps it's more a design and application failure than a product failure. A design that could filter the lube oil before tying to use it might be all that's needed.

Top tip:- Always use magnetic drain plugs.

I’ve never seen, firsthand, a failed hub bearing & tend to use the originals, even with some element of play in them compared to a fresh, deep groove ball bearing. Due to the cantilever effect of the lay-shaft journals, I’m fussier about the needle bearings on the other end of the lay-shaft as quality (Ina etc) needle bearings are readily available as well as ensuring that the hub & cone are lapped in.

I’m certainly not cynical that debris may cause failure, but believe it would have to be huge to have caused the type we see in the image above, especially when the drain magnets are in places. In fact, in competition use, I’ve used magnetic drains in the ‘level’ position, as well. Breaking a gear tooth was fairly commonplace & either magnet would usually capture the broken pieces, enabling completion of a race, (with the obligatory left hand hovering over the clutch lever, yet more so)

Somehow, the cage we see here, has failed in its function.

However, ‘open mind’ & all that!

It will be interesting to know what the Vendor has to say about his own brand of bearing & it’s failure....

Am I correct in thinking that "lapping " in the cone and hub you should use valve grinding paste ?
Also what's the best way to actually do it (an old layshaft perhaps)?

Phil D wrote:Am I correct in thinking that "lapping " in the cone and hub you should use valve grinding paste ?
Also what's the best way to actually do it (an old layshaft perhaps)?

Sorry, but yes, a spare lay-shaft in a vice works (with grinding paste) but you need to pack it so that the splines don’t engage with the hub.

I suppose it can be done in situ, but it is a bit unwieldy, I would imagine.

The one time I saw it (Many years ago) The roller shells on the chain had broken up and we figured that one of these sharpe pieces had gotten lodged in the bearing causing the break-up of the cage. I can't be absolutely certain about this but judging from the mitigating evidence it made sense.
Also... It was an Indian bike and it was common for Indian machines to not have a mag drain fitted as standard.

I poked the plastic cage out of an MB bearing by mistake and it looked like that.

Bugger of a job getting it back in.