layshaft bearing

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stu

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Jul 22, 2012
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commute into town yesterday, pulling away from the lights and the kicker knocks back sharply about 45degrees. Pulled off into a side road and all sounds smooth but i'm thinking layshaft bearing failure. 3 miles through town at slow speeds and nearly at work, same thing again pulling away in first from a set of lights. This time i can hear a roughness rolling the bike with the engine off so its a call to the AA and a lift back to the shed.

I've done a bit of reading and have Mick Hemmings excellent workshop dvd so looking forward to learning all about gearboxes and (most likely) layshaft bearing replacement.

I'd be inclined to go with Micks advice and fit the FAG 6203 TB bearing but I wondered if concensus had changed much over the last few years (RGM and Andover seem to favour/sell roller bearings) Also - is Mick still taking telephone orders ?

thanks
Stu
 
The TB bearing gets my vote after using both types.
The roller is OK but doesn't positively locate the layshaft.
Shimming is necessary and caused me some issues with the kickstart shaft being pushed back into the case.
A quick call should answer the other question - I haven't bought off them this year but Angie is very helpful.
 
Mick is still open for business, just not sure what that is though, parts or rebuilds ?
 
Hi Stu,
It does sound like it's the layshaft bearing.
The roller bearing works well and for me has proven reliable though you might have to reduce end float with shims. The solid brass caged ball race could be the better option as the usual cause of failure is not the rolling elements but the wire cage breaking up. Check the bush for wear at the same time.

Dave
 
cash said:
The solid brass caged ball race could be the better option as the usual cause of failure is not the rolling elements but the wire cage breaking up.
Click to expand...

I don't believe I've heard of a solid brass cage ball bearing option before, or think why any solid cage ball bearing would be better than the 'Hemmings' 6203 TB bearing which I would also recommend? :|
 
Thanks all - I'll try Mick again and order up the 6203 TB.

btw - Kommando, wherabouts in Scotland are you ? I'm Fife - regular commuter over the bridge to Edinburgh on a 750 roadster (until recently anyway)
 
So, does anyone have a source for the 6203 TB in the US? I found FAG 6203-TB-P63 at 123 Bearings with an internet search but wonder if any of the US Norton suppliers provide this bearing.

Ed
 
APRRSV said:
So, does anyone have a source for the 6203 TB in the US? I found FAG 6203-TB-P63 at 123 Bearings with an internet search but wonder if any of the US Norton suppliers provide this bearing.

Ed
Click to expand...

Purvis Industries is a FAG distributor. You will have to call your nearest outlet and speak to a rep. They will sell in quantity of one. Might have to wait 2-3 weeks .

http://purvisindustries.com/locations.html

Slick

PS: Don't say it is for a motorcycle .... tell 'em it's for an air compressor.
 
APRRSV said:
So, does anyone have a source for the 6203 TB in the US? I found FAG 6203-TB-P63 at 123 Bearings with an internet search but wonder if any of the US Norton suppliers provide this bearing.

Ed
Click to expand...


Be careful of this source. Mine was not the same as Mick's so I sent it back. Country of manufacture was not the same, labeling also.
This PN bearing should be made in Portugal, like his. I bought from Mick's stock to be sure. His delivery to the US was fast, less than 1 week.
 
elefantrider said:
APRRSV said:
So, does anyone have a source for the 6203 TB in the US? I found FAG 6203-TB-P63 at 123 Bearings with an internet search but wonder if any of the US Norton suppliers provide this bearing.

Ed
Click to expand...


Be careful of this source. Mine was not the same as Mick's so I sent it back. Country of manufacture was not the same, labeling also.
This PN bearing should be made in Portugal, like his. I bought from Mick's stock to be sure. His delivery to the US was fast, less than 1 week.
Click to expand...

Agree! There are a lot of counterfeit bearings out there. Purvis Ind. has a big red warning label on their Home Page re. bogus bearings.

Slick
 
I went with the CNW open roller bearing on my rebuild. I eliiminated the gaskets and used the grey sealant (forget the name) My kickstart doesn't have excessive side play that I can see... but maybe it does and I am too clueless to observe it... The choice between roller and ball may be moot if both improved bearings outlast the rest of the gearbox parts. I like roller bearings, so I went with the spec'd CNW roller bearing. I can't imagine mick hemmings suggested a bearing which is a poor choice either... I would bet money that you could chose either and be totally fine...

I also installed the CNW sealed mainshaft inner bearing to cut down on any gear oil leaks at the output shaft. That has worked flawlessly too.
 
o0norton0o said:
I went with the CNW open roller bearing on my rebuild. I eliiminated the gaskets and used the grey sealant (forget the name) My kickstart doesn't have excessive side play that I can see... but maybe it does and I am too clueless to observe it... The choice between roller and ball may be moot if both improved bearings outlast the rest of the gearbox parts. I like roller bearings, so I went with the spec'd CNW roller bearing. I can't imagine mick hemmings suggested a bearing which is a poor choice either... I would bet money that you could chose either and be totally fine...

I also installed the CNW sealed mainshaft inner bearing to cut down on any gear oil leaks at the output shaft. That has worked flawlessly too.
Click to expand...

After watching Comnoz's excellent video I also went with a roller. There's really no thrust issue on the shaft and the explanation for shimming the kick shaft makes sense.

I think that if I ever have to disassemble the box for any other reason, such as to install a sealed main shaft bearing, the process will be faster as one can just remove the layshaft without resorting to heat again. A slight advantage, I know but I also like roller bearings where appropriate.
 
With the roller bearing, how do you pull the bearing out for inspection without removing the gearbox, or destroying the bearing (taking the rollers out)?

Can you use heat and get a puller behind the rollers? Will heat and a puller damage the rollers and plastic cage?
 
You don't have to remove the roller brg to remove the layshaft, it just slips out. A big advantage in my book.
Jaydee
 
Use a heat gun to remove the bearing, if you need to. The inner race will pull out with the layshaft.
Cheers,
Thomas
 
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