Hemmings Layshaft bearing

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to quote pete v

No you can't. And if you had made an effort to make said purchase of a 6203-tb-p6-c3 (aka 6203TB.P63) you would have known for yourself.

But let's give you the benifit of the doubt. There must be dozens global FAG distributors. Please offer up three or four to choose from with pricing and availability.


I will even start it up for you. Notice that the country of orgin is subject to change and the available to order status mean "not in stock". Oh, and don't forget about the price.
http://www.motionindustries.com/motion3 ... q=02297983

Here is another under a different number. Notice the price and availability. I double dog dare you to call this distributer and try to order one. "Non Exsistant" Their FAG rep will tell you what they told me. That FAG has reclassified these bearings and they will be around $300 each and be exclusively made in Germany.
http://www.applied.com/apps/commerce/ca ... 203-TVH-C3

YOU ARE QUICK TO FORGET SIR the good old USA has ( trade restrictions on bearing import ) in the form of a high import duty tariff for foreign made bearings
to protect any USA bearing manufacturing from cheap imports ( in Europe we have a free trade policy ) and our bearing brokers can source without restriction

your FAG / SKF / RHP US distributors may choose not to import due to duty issues and MOQ batch production / sales issues , In Europe we have bearing brokers who actually buy up manufacturers production runs and then supply local distribution companies which all have trade / retail outlets in most sizable towns and city`s

I can assure you we in the UK we can go down to our local distributors and obtain them ( if they are available for sale )

through my work I have regular dealings with one of the UK bearing brokers these guys hold more than 1 million bearings in stock at all times and have access to all global manufacturers stock lists and production dates so they can tell you how much and how long normally within 24 hours and strange as it may seem they also have access to competitors stock lists as they all freely trade stocks
 
kiwi said:
YOU ARE QUICK TO FORGET SIR the good old USA has ( trade restrictions on bearing import ) in the form of a high import duty tariff for foreign made bearings
to protect any USA bearing manufacturing from cheap imports ( in Europe we have a free trade policy ) and our bearing brokers can source without restriction
Click to expand...
Quick to forget? Uppercase? I am afraid that I am just not that astute in bearing lore or legalese. My field is in application, yours seems to be acquisition. All differences aside, we may have chance.


kiwi said:
I can assure you we in the UK we can go down to our local distributors and obtain them
Click to expand...
How fortunate for you.



kiwi said:
( if they are available for sale )
Click to expand...
I guess that's the whole jist of it, isn't it.


Thanks, B.Rad :oops:
 
Im just trying to get a bit of perspective on this layshaft bearing thing so please correct me if Im wrong with any of this

• Early Commandos had a 6203 steel cage bearing of some sort, and although it may not be the best they werent a massive problem either.
• At some stage the bearing suppler/quality changed and the cages would fail leading to gearbox lockup.
• At some stage Hemmings et al found that the 6203 TB P63 was reliable in this application and did not suffer cage failure.

6203 = Single row deep groove ball bearing 17*40*12mm C 10.1kN
TB = Machined textile laminated phenolic cage
P63 = P6 is a tolerance class for the ID and OD of the bearing and is a tighter tolerance than standard (this does not necessarily mean a tighter fit), although it looks like SKF bearings are made to P6 as standard anyway. C3 is the internal radial clearance of the bearing (balls to race) and is lager than standard.

The problem at the moment seems to be finding a bearing with the laminated textile cage, C3 clearance not a problem, P6 not all that important, good quality steel cages used to work.

Now with this in mind there are definitely other deep groove ball bearings that will work, for instance an SKF 6203 ETN9 C 11.4kN (it would still have to be C3 or C4) may be suitable. I would bet that there is an NSK and FAG version of this as well.

Then there is the roller bearing which I think is a much better solution......
Some will argue that this is in the too hard basket as it needs shimming, however realistically the deep groove ball also needs shimming as it does not positively locate the layshaft.
 
Cheesy said:
Early Commandos had a 6203 steel cage bearing of some sort, and although it may not be the best they werent a massive problem either.
• At some stage the bearing suppler/quality changed and the cages would fail leading to gearbox lockup.
Click to expand...

Any standard steel or brass cage 6203 layshaft ball bearing can potentially fail, so the problem is not entirely confined to the Portuguese-made 6203 bearing although the failure rate of Portuguese bearing seems higher.
 
mkv750 said:
Hello NorBecer,

The price difference will be down to the suppliers, apparently the bearings are not too easy to get hold of!, and the prices do fluctuate some!!, guess I was lucky on the day!.

I will agree, very nice people to deal with, I have just ordered the engine and gearbox DVD's, and also have an article showing Mick Hemmings rebuilding the AMC box, classic and motorcycle mechanics, very good article.

John
Click to expand...

John,I have the DVDs as well, they are better than GREAT! Super well detailed, gives me the confidence I needed to dig in! Good luck with your project!
Best, Dennis
 
Cheesy said:
Im just trying to get a bit of perspective on this layshaft bearing thing so please correct me if Im wrong with any of this

• Early Commandos had a 6203 steel cage bearing of some sort, and although it may not be the best they werent a massive problem either.
• At some stage the bearing suppler/quality changed and the cages would fail leading to gearbox lockup.
• At some stage Hemmings et al found that the 6203 TB P63 was reliable in this application and did not suffer cage failure.

6203 = Single row deep groove ball bearing 17*40*12mm C 10.1kN
TB = Machined textile laminated phenolic cage
P63 = P6 is a tolerance class for the ID and OD of the bearing and is a tighter tolerance than standard (this does not necessarily mean a tighter fit), although it looks like SKF bearings are made to P6 as standard anyway. C3 is the internal radial clearance of the bearing (balls to race) and is lager than standard.

The problem at the moment seems to be finding a bearing with the laminated textile cage, C3 clearance not a problem, P6 not all that important, good quality steel cages used to work.

Now with this in mind there are definitely other deep groove ball bearings that will work, for instance an SKF 6203 ETN9 C 11.4kN (it would still have to be C3 or C4) may be suitable. I would bet that there is an NSK and FAG version of this as well.

Then there is the roller bearing which I think is a much better solution......
Some will argue that this is in the too hard basket as it needs shimming, however realistically the deep groove ball also needs shimming as it does not positively locate the layshaft.
Click to expand...

Cheesy, well put. I like your thinking and agree with almost everything you said. I may disagree with the shimming part but that just me.

I might add one more thing and that is the abuse factor. It is hard to determine how hard these failed bearing gearboxes bearings were used, particularly the Combat or higher torque 850's.
We're adding cams, pipes, beltdrives, all kinds of intake solution, brake upgrade, high speed tires and on and on and on. These gearboxes need to be treated with even more care than before.

I think they are great gearboxes if used within the realm of their limits. I also think the forces put on the layshaft and its relationship to the layshaft bearing must be concidered during hard shifting and/or
engine braking.

A true advantage to these units are how easy they are to work on. Thank goodness.
 
L.A.B. said:
Cheesy said:
Early Commandos had a 6203 steel cage bearing of some sort, and although it may not be the best they werent a massive problem either.
• At some stage the bearing suppler/quality changed and the cages would fail leading to gearbox lockup.
Click to expand...

Any standard steel or brass cage 6203 layshaft ball bearing can potentially fail, so the problem is not entirely confined to the Portuguese-made 6203 bearing although the failure rate of Portuguese bearing seems higher.
Click to expand...

Thats interesting, so basically there is a fundamental design issue with using the 6203 bearing in this application, unless the problem stems from people not using C3 or C4 bearings which may account for the cages failing as opposed to badly pitted/spalled balls and races that would be more likely for an overload failure.
 
pete.v said:
Cheesy, well put. I like your thinking and agree with almost everything you said. I may disagree with the shimming part but that just me.

I might add one more thing and that is the abuse factor. It is hard to determine how hard these failed bearing gearboxes bearings were used, particularly the Combat or higher torque 850's.
We're adding cams, pipes, beltdrives, all kinds of intake solution, brake upgrade, high speed tires and on and on and on. These gearboxes need to be treated with even more care than before.

I think they are great gearboxes if used within the realm of their limits. I also think the forces put on the layshaft and its relationship to the layshaft bearing must be concidered during hard shifting and/or
engine braking.

A true advantage to these units are how easy they are to work on. Thank goodness.
Click to expand...

Ill meet you in the middle, some gearboxes need shimming with balls, although I have a roller in mine it would have needed shimming with a ball as well, way too much float in the kick start shaft, and also not enough clearance between inner face of 1st gear and the end of the kick start shaft
 
I know it's all been said before, but what the hell..

The original gearbox design was fine (Model 50, G3LS, etc), but increased power imposes flex into the mainshaft with correspondingly increased flex onto the layshaft via the gears - I have quite a collection of spalled gears which bear witness to this.
Steve Maney's outrigger and the Factory JPN racers introduced a third mainshaft bearing immediately behind the clutch which controls the mainshaft flex. In this case I presume the standard bearing would still be well up to the job.

The bearing fails because the cage breaks up due to the flex (whirl, whip or whatever) in the layshaft, which is progressively prising the cage apart.
The bearing is up to the job it was designed for, but the gearbox is being used outside its original design parameters.

The Hemmings bearing - like the superblend roller - accommodates the flex, and still positively locates the layshaft. I've used both, and the roller is coming out of my 850 gearbox at the first opportunity, as I've had to re-shim it twice, and every time I do the kickstart shaft migrates further into the outer cover, compromising the kickstart location on the spline. I've had to take off my beloved RGM T160-style kicker for this reason.

Buy one from Mick - it's worth it just to talk to Angie - she's more unique than most!
 
B+Bogus said:
Buy one from Mick - it's worth it just to talk to Angie - she's more unique than most!
Click to expand...
I just wanted to echo this part because I think that if you buy from a bearing supplier etc... then your supporting them in their business, if you buy from Mick then you are supporting a business that directly supports Norton's. To me, it's worth the extra 10 or 20 just for that. IMHO
 
B+Bogus said:
I know it's all been said before, but what the hell..

The original gearbox design was fine (Model 50, G3LS, etc), but increased power imposes flex into the mainshaft with correspondingly increased flex onto the layshaft via the gears - I have quite a collection of spalled gears which bear witness to this.
Steve Maney's outrigger and the Factory JPN racers introduced a third mainshaft bearing immediately behind the clutch which controls the mainshaft flex. In this case I presume the standard bearing would still be well up to the job.

The bearing fails because the cage breaks up due to the flex (whirl, whip or whatever) in the layshaft, which is progressively prising the cage apart.
The bearing is up to the job it was designed for, but the gearbox is being used outside its original design parameters.

The Hemmings bearing - like the superblend roller - accommodates the flex, and still positively locates the layshaft. I've used both, and the roller is coming out of my 850 gearbox at the first opportunity, as I've had to re-shim it twice, and every time I do the kickstart shaft migrates further into the outer cover, compromising the kickstart location on the spline. I've had to take off my beloved RGM T160-style kicker for this reason.

Buy one from Mick - it's worth it just to talk to Angie - she's more unique than most!
Click to expand...

The roller bearing (no such thing as a superblend) does not accommodate the flex, in fact they are much less tolerant of it than the ball, I think they survive in this situation though just because the load rating is around 4 times that of the ball (from memory), this is probably why Mick recommends the ball.

The other thing is to think through how we end up with angular missalignment in the bearing, the steel case bush to kickstart shaft and then the bronze bush in the kickstart shaft. I wounder if there is any correlation between a worn bush in the kickstart shaft and bearing failure....
 
Cheesy said:
The roller bearing (no such thing as a superblend) does not accommodate the flex, in fact they are much less tolerant of it than the ball, I think they survive in this situation though just because the load rating is around 4 times that of the ball (from memory), this is probably why Mick recommends the ball.
Click to expand...

Not all roller bearings are alike. The proven 306 crankshaft roller bearing (drive side) failed in large numbers when Norton introduced the more powerful Combat, caused by high revs crankshaft flex. The succesfull solution was the 306E roller bearing (so called "superblend") to cope with the flex. This type of roller bearing certainly does accommodate flex and used in our gearbox it will outlast any ball bearing :!: About end float: keep the mainshaft tight, some layshaft end float is no problem at all :!:
 
nortonspeed said:
Cheesy said:
The roller bearing (no such thing as a superblend) does not accommodate the flex, in fact they are much less tolerant of it than the ball, I think they survive in this situation though just because the load rating is around 4 times that of the ball (from memory), this is probably why Mick recommends the ball.
Click to expand...

Not all roller bearings are alike. The proven 306 crankshaft roller bearing (drive side) failed in large numbers when Norton introduced the more powerful Combat, caused by high revs crankshaft flex. The succesfull solution was the 306E roller bearing (so called "superblend") to cope with the flex. This type of roller bearing certainly does accommodate flex and used in our gearbox it will outlast any ball bearing :!: About end float: keep the mainshaft tight, some layshaft end float is no problem at all :!:
Click to expand...

If the "E" does accommodate angular misalignment I would have expected it to be mentioned in the application notes unless Im missing something?
I did get the load capacity wrong for the roller, its only 17kN, still significantly more than the ball
 
Hi Gents, I just received my Mick Hemmings layshaft bearing that my buddy's daughter brought back from the UK. In the photo you can clearly read the digits. No more guessing as to what model he uses 6203 TB :wink:

[ATTACH=full]27819[/ATTACH]
 

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NORBECER said:
In the photo you can clearly read the digits. No more guessing as to what model he uses 6203 TB :wink:
Click to expand...

Mick has been using/supplying that FAG 6203 TB bearing for several years. :)
 
L.A.B. said:
NORBECER said:
In the photo you can clearly read the digits. No more guessing as to what model he uses 6203 TB :wink:
Click to expand...

Mick has been using/supplying that FAG 6203 TB bearing for several years. :)
Click to expand...

Yes I understand that but others seemed to be a little confused about which one he actually puts into his gear box rebuilds so I thought I would share :)
 
Looks just like the bearing I started this thread with 4 years ago.
 
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