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dodgy main bearing

Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models

dodgy main bearing

Postby peejay » Fri Nov 09, 2018 5:56 pm

hi peeps
this bearing has done just 3,000 miles in 3 years and is knackered enough to blow the oil seal

Image

it was bought from a well known dealer and came in what looked like genuine packaging.

a couple of months ago a similar bearing bought from another dealer in similar packaging failed after just 1'000 miles!!

both bearings were fitted by a very competent mechanic.

has anyone else had similar problems?

cheers

PeeJay
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Re: dodgy main bearing

Postby Adam_Winstone » Fri Nov 09, 2018 6:22 pm

This frustrates me as I've had concerns about the Indian FAG bearings that I have had too, however, I have so far not run into any problems. Fingers crossed that genuine FAG from other countries with genuine FAG factories, not fakes, are of suitably high standard. I've always used FAG or SKF bearings and hope that they will continue to serve me well.

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Re: dodgy main bearing

Postby Scooterdude » Fri Nov 09, 2018 6:32 pm

That looks very dry, not as I’d expect to see a bearing that has been swimming in gearbox oil. I know that on some of these bearings they come with a fitted metal seal that has to be winkled out with a screwdriver prior to fitting, is it possible that it hasn’t?
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Re: dodgy main bearing

Postby Fast n Furious » Fri Nov 09, 2018 7:49 pm

There's also signs of overheating consistent with a lack of lubrication.
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Re: dodgy main bearing

Postby peejay » Sat Nov 10, 2018 2:24 am

Adam_Winstone wrote:This frustrates me as I've had concerns about the Indian FAG bearings that I have had too, however, I have so far not run into any problems. Fingers crossed that genuine FAG from other countries with genuine FAG factories, not fakes, are of suitably high standard. I've always used FAG or SKF bearings and hope that they will continue to serve me well.

Adam


thanks Adam
FAG and SKF are our preferred bearings so far.

the word "KOREA" did surprise me
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Re: dodgy main bearing

Postby peejay » Sat Nov 10, 2018 2:26 am

Scooterdude wrote:That looks very dry, not as I’d expect to see a bearing that has been swimming in gearbox oil. I know that on some of these bearings they come with a fitted metal seal that has to be winkled out with a screwdriver prior to fitting, is it possible that it hasn’t?


i'm sure our engine man would have noticed this metal seal, i'll ask the question :)
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Re: dodgy main bearing

Postby peejay » Sat Nov 10, 2018 2:29 am

Fast n Furious wrote:There's also signs of overheating consistent with a lack of lubrication.


the bearing does look a bit on the dark side i agree, the scoot in question was smoking like a very smokey thing when 30 miles from home
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Re: dodgy main bearing

Postby Scooterdude » Sat Nov 10, 2018 6:49 am

peejay wrote:
Scooterdude wrote:That looks very dry, not as I’d expect to see a bearing that has been swimming in gearbox oil. I know that on some of these bearings they come with a fitted metal seal that has to be winkled out with a screwdriver prior to fitting, is it possible that it hasn’t?


i'm sure our engine man would have noticed this metal seal, i'll ask the question :)

Well judging by your dry overheated bearing failing in such a short space of time and having a second one go in even less time might I suggest your “engine man” is getting something wrong or missing the obvious so yes definitely ask him the question :?

I notice you have used the C3 spec bearing, good choice and popular with many builders, I’ve built a few engines using these bearings both from FAG and also Koyo without issue, I’ve also used the “M” spec bearing from Koyo in a couple of builds including my own again without issue.
The “M” spec are a tighter tolerance than the C3 and as you probably already know are widely used in electric motors and generators for this reason.

Good luck and let us know what he says.
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Re: dodgy main bearing

Postby davej » Sat Nov 10, 2018 10:34 am

Having fitted many Drive Bearings,I am very cofident in what I do, To clarify points raised:
1. Bearing fitted with RS seal only on the crank side
2. Torch used to free bearing hence heat marks
3. Bearing has been wiped after extraction
4. Wear in bearing noticed when oil seal failed and gearbox oil burning
5. Showed bearing to a 2 stroke motorcycle expert he agreed it was a faulty bearing
6. The two bearings were fitted in two differint bikes
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Re: dodgy main bearing

Postby lam1962brettagg » Sat Nov 10, 2018 12:46 pm

Hi Yep have had the same prob with Korea bearings again from reputable dealer. first one started rusting after only 2 months in well oiled engine .
second is overheating and will be coming out soon.
thought it was just me and the way i fitted it or somethin.
hope you get a descent one.
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Re: dodgy main bearing

Postby Scooterdude » Sat Nov 10, 2018 2:07 pm

davej wrote:Having fitted many Drive Bearings,I am very cofident in what I do, To clarify points raised:
1. Bearing fitted with RS seal only on the crank side
2. Torch used to free bearing hence heat marks
3. Bearing has been wiped after extraction
4. Wear in bearing noticed when oil seal failed and gearbox oil burning
5. Showed bearing to a 2 stroke motorcycle expert he agreed it was a faulty bearing
6. The two bearings were fitted in two differint bikes

Ok fair enough. Funny thing FAG bearings had two identical one marked made in Korea and one marked made in India. So if your confident you got the build right all to do is change bearing brand and see how it goes.

I once had a FAG Indian rear hub bearing off of a very reputable dealer, upon inspection it was clear it was way out of tolerance to the point that it was worce than the one i was replacing not only that it had patches of rust all over it, so yes definitely bad ones out there floating about.
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Re: dodgy main bearing

Postby Fast n Furious » Sat Nov 10, 2018 2:37 pm

Scooterdude wrote:
davej wrote:Having fitted many Drive Bearings,I am very cofident in what I do, To clarify points raised:
1. Bearing fitted with RS seal only on the crank side
2. Torch used to free bearing hence heat marks
3. Bearing has been wiped after extraction
4. Wear in bearing noticed when oil seal failed and gearbox oil burning
5. Showed bearing to a 2 stroke motorcycle expert he agreed it was a faulty bearing
6. The two bearings were fitted in two differint bikes

Ok fair enough. Funny thing FAG bearings had two identical one marked made in Korea and one marked made in India. So if your confident you got the build right all to do is change bearing brand and see how it goes.

I once had a FAG Indian rear hub bearing off of a very reputable dealer, upon inspection it was clear it was way out of tolerance to the point that it was worce than the one i was replacing not only that it had patches of rust all over it, so yes definitely bad ones out there floating about.


I concur. Had the same issue a number of times with these Indian made rear wheel bearings. There are some good ones out there now but don't fit the ones with the plastic race cages. These are dangerous.
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Re: dodgy main bearing

Postby nickw » Sat Nov 10, 2018 3:16 pm

I can't remember how long ago but a local dealer also had problems with same bearings with almost same problems identified here. IMO nothing to do with dealer or fitter. They are fake bearings I believe and difficult to identify.
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Re: dodgy main bearing

Postby peejay » Sat Nov 10, 2018 11:40 pm

thanks guys for your replies

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Re: dodgy main bearing

Postby Ranburetta » Sun Nov 11, 2018 12:24 am

Get my bearings from a specialist trading from bricks and mortar where I can go in, inspect and buy.

I was warned by them some time ago about fake FAG but fortunately they are big enough to deal direct with the manufacturers.

I always insist on branded European or Japanese made, but never been impressed by FAG and no longer use them.

Still using my stash of NOS RIV rear hub bearings (not the re-made ones good as they may be) but I only have three or four left.

[url][URL=http://s58.photobucket.com/user/Botohp/media/RIV_zpsvsbtuv0m.jpg.html]Image[/url][/url]
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Re: dodgy main bearing

Postby nsaints » Mon Nov 15, 2021 1:11 pm

Just experienced an issue with a FAG main bearing, this time non drive side
The machine in question was restored approx 6 years ago by AN Other not known to me directly, and still hasn't been run in (I don't know the exact mileage), but I'll guess sub 500 miles based on piston wear

approx 40 mph the Scooter would start shuddering with vibration. Close inspection revealed the flywheel would move up and down by approx 1mm :(

Pulling the mag flange off revealed a FAG (made in Germany version) roller bearing. the inner race mounted on the crank had weird (not what I'd expect to see) wear marks, mainly a lot of wear around one part of the bearing inner track circumference.
I suspected a fake bearing or a genuine FAG bearing with a manufacturing defect

I bought new FAG main bearings from a scooter dealer, and whilst researching the fake bearing problem found a 'world bearing association' (WBA) website with an aim to stop fake bearings. https://www.stopfakebearings.com/ - There's a smart phone app to scan bearing packaging, which cross checks the serial numbers and markings with the manufacturers database - as a user you get instant feedback. yes genuine, or possible fake check with manufacturer.

So I scan the new FAG bearings - one genuine, one reported as possible fake!!
I send the bearings back for a refund with an explanation. Apologize from the very good dealer, they take the matter up with their supplier
I still use the dealer to this day

I thought I'd bypass scooter dealers and found a supplier (not ebay) of SKF bearings instead of FAG
Bearings came - tried the genuine/fake bearing app - all reported as fake (Grrrrr)

So - Next step I contact SKF who have their own department to check bearing validity genuine/fake
1st response from SKF always use their dealer network (the supplier I found wasn't one)
2nd they asked for lots of detailed photo's of the bearings and packaging

Next day SKF came back and confirmed the bearings were genuine after all - sigh of relief

so lesson's learn't
1 - I'll go directly next time to a manufacturers supplier - so what if it costs a £1 or so more for a bearing. Piece of mind and all that
2 - the WBA app isn't totally reliable - as such I'm not sure the FAG bearing I was initially supplied was fake or not. I'm happier with SKF bearings now SKF have confirmed they're genuine anyhow

The flywheel no longer moves up and down with the new bearings fitted - still haven't finished the engine rebuild, so no feedback on the vibration and whether it's sorted
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Re: dodgy main bearing

Postby hullygully » Mon Nov 15, 2021 2:04 pm

your mag brg could be new in the housing but sounds like the crank half didn't get changed :roll:
as for the drive bearing, or any brg for that matter, they're all mechanical & can fail @ any time, hence why you should try to purchase quality
I've just spent 3 weeks trying to shim up an Indian 150 (changed layshaft, g/box, endplate, shimmed the layshaft) with a FAG rear hub brg, only to find the flange (that sits in the casing) thickness to be 6.80mm (bigger than 3.0mm shim :shock: ), as opposed to any other old stock one of 6.0mm
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Re: dodgy main bearing

Postby nsaints » Mon Nov 15, 2021 2:22 pm

At our club meeting we did discuss the strange inner track wear, and the possibility of a non matched inner track to roller bearing as the cause for the excessive flywheel movement was suggested, along with crank out of alignment causing excessive wear, or flywheel massively out of balance (you have to see the wear marks for the flywheel suggestion to make sense).

Once I had removed the inner track from the new MEC style crank and could see the markings, the inner track is FAG and being a new crank kinda discounts your valid suggestion
I took the crank to a motorcycle dealer and it was within the 1 thou tolerance so crank out of alignment is not a cause

I don't know about the flywheel being out of balance, but have sourced a replacement genuine Ducati flywheel to replace the Indian bolt in boss flywheel

it's back to fake or poorly manufactured genuine parts as the explanation as favourites :roll:
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Re: dodgy main bearing

Postby Warkton Tornado No.1 » Mon Nov 15, 2021 4:50 pm

Perhaps because I am a time served engineer, it surprises me that power transmission products are sourced from 'Lambretta specialists' for any reason whatsoever. Other than the Lambretta specific rear hub bearing*, the power transmission components are a common part. I wonder how Lambretta enthusiasts can truly be unaware of the fact! There can't be many of us that haven't read Dave Webster's tuning manual in which it clearly states the fact. Yet people still buy Rolon chain :lol:

Unfortunately, counterfeit goods exist, the profits of which may fund any types of horrific intentions. Genuine FAG bearings are as good as you can buy, as are all genuine 'West European' & Japanese bearings. There are specific manufacturing plants producing only certain genuine bearings, to be shipped out with any of a number of manufacturer's markings, including Ina, Koyo, Nadella, SKF, Timken etc. They are all appropriately sold through a network that does not risk inferior products.

As a point of fact, CN (Class Normal) is the base line class of running clearance for a bearing. C2 are tighter, whereas C3 has more clearance & the class of bearings specific for engine assembly upon initial build where everything is brand new. Many years on, the bearing journals in an engine crankcase & magneto housing are unlikely to have remained the exact same size. More likely that they will be enlarged. The material is a soft alloy rather than a hardened steel, so the transition fit will be affected by bearings being fitted, removed, vibration, heat cycling etc. For that reason, I have used CN bearings & they are my preference. In fact, during the 80's,I had obtained some tighter bearings that I wished to trade with. They were NU2205 E C2 & MSC had the lot from me.


* IMHO the OEM Innocenti/Spanish rear hub bearing is/was the best available without compromise. Of the two alternatives available, the MB plastic caged bearings are potentially dangerous & the other AF product places the rear wheel off line.
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