 |
|
|---|
Good News, Bad News, and Really Bad News!
Re: Good News, Bad News, and Really Bad News!
by britbike220 » Wed Sep 01, 2010 9:11 am
Crap, now I'll be worried my whole trip to barber and back.
-
britbike220 - Posts: 1305
- Joined: Sat Aug 06, 2005 1:53 pm
- Location: princeton Illinois
Re: Good News, Bad News, and Really Bad News!
by pkeithkelly » Wed Sep 01, 2010 9:54 am
I see a couple of references to the 12,000 mile mark as a potential failure point for lay shaft bearings.
My Mark III just ticked over 21,000 miles, and had 14,000 when I bought it 3 years ago. I don't think the previous owner did anything to the gearbox, so my bike and its lay shaft bearing made it a long way past the 12,000 mile point.
The best part, though, is that it failed when I was just pulling out of a parking spot in a parking lot, in first gear, and going 5 miles per hour.
Failure a mile earlier or a mile later would have been downright ugly.
My wife is more shook up about this than I am, since I have more than one bike and ride about 15,000 miles a year. She thinks this is a motorcycle issue, as opposed to a 35 year old Brit bike issue. I am more concerned about the down time, hassle and cost to get the Commando back in action.
Oh well.... ride on. What else can you do?
My Mark III just ticked over 21,000 miles, and had 14,000 when I bought it 3 years ago. I don't think the previous owner did anything to the gearbox, so my bike and its lay shaft bearing made it a long way past the 12,000 mile point.
The best part, though, is that it failed when I was just pulling out of a parking spot in a parking lot, in first gear, and going 5 miles per hour.
Failure a mile earlier or a mile later would have been downright ugly.
My wife is more shook up about this than I am, since I have more than one bike and ride about 15,000 miles a year. She thinks this is a motorcycle issue, as opposed to a 35 year old Brit bike issue. I am more concerned about the down time, hassle and cost to get the Commando back in action.
Oh well.... ride on. What else can you do?
Keith Kelly
'75 Mark III
2007 Harley Fat Boy
2004 Ducati 999 Teststrata
2006 Suzuki DR 650SE
Check out this cool site: http://www.myridz.com
'75 Mark III
2007 Harley Fat Boy
2004 Ducati 999 Teststrata
2006 Suzuki DR 650SE
Check out this cool site: http://www.myridz.com
-
pkeithkelly - Posts: 217
- Joined: Wed Sep 26, 2007 1:54 pm
- Location: Oceanside, California
Re: Good News, Bad News, and Really Bad News!
by 79x100 » Wed Sep 01, 2010 10:02 am
It's a full strip to replace the bearing as it is deep in the case. The NOC Service notes stated that it was most likely to occur with larger (greater than 21t) gearbox sprockets.
It has been stated on the forum a number of times but you'll find no experienced long-term owners giving you any advice other than 'replace it' Once it's sorted then you'll never need to do it again.
Failure is so potentially disastrous that the only sensible course id to do it as soon as possible. In the meantime, watch your kick start lever like a hawk for signs of flinging back.
I expect we'll be seeing some photographs soon of what goes on.
If Pkeithkelly's has only trashed the bearing then it's an easy job over a weekend.
It has been stated on the forum a number of times but you'll find no experienced long-term owners giving you any advice other than 'replace it' Once it's sorted then you'll never need to do it again.
Failure is so potentially disastrous that the only sensible course id to do it as soon as possible. In the meantime, watch your kick start lever like a hawk for signs of flinging back.
I expect we'll be seeing some photographs soon of what goes on.
If Pkeithkelly's has only trashed the bearing then it's an easy job over a weekend.
1975 850 MkIII
1939 WD16H
Compulsive tinkerer.
1939 WD16H
Compulsive tinkerer.
-
79x100 - Posts: 1377
- Joined: Fri May 19, 2006 2:25 pm
- Location: Flanders/ UK if there's a jumble on.
Re: Good News, Bad News, and Really Bad News!
by hobot » Wed Sep 01, 2010 10:04 am
1973 850, I was leaving work and as I got into third gear the Universe went NUTS, the rear wheel locked up, the front wheel made a fast and ugly trip back to the pavement (hey, I was 18 and the Commando was FUN to pound on!). I ended up having the 'box rebuilt 7 times in 9 years and it was not until years after I sold the bike that I determined I had pulled the Case out of square and the rebuilds were just hiding the symptoms (for a while, anyway). That day (pretty much) ended my Wheelie-career, surprises on one wheel SUCK!
Unclviny and me have similar events with identical conclusions. Can not go by mileage at all as a single event like to tight a primary drive or an item breaks in gearbox - can mean whole power train distorted - cases to shafts to bearings and cogs and control linkages. Trixie Combat I'm about to re-do engine on, locked up instantly at 50 mph cruise so I'm pensive as hell the drive train may catch me out during mere break in interval. I think re-used rod bolt let go, as one had corroded fracture face the other did not.
It can cost nearly $1000 to get a really broke bike back home form out of the way locations. A weekend to motel while locating a truck that maybe 10's of miles away and way over size but only thing available. Its about a wash if trying to repair major stuff far from home. Moteling-camping awaiting parts and shops to fix. Too often climate dictates and inside job.
Travel long and safe in scared confidence.
hobot
Throw yourself at the ground and miss!
-
hobot - Posts: 6520
- Joined: Wed Oct 19, 2005 6:59 pm
- Location: Arkansas, Dixieland
Re: Good News, Bad News, and Really Bad News!
by MarshalNorton » Wed Sep 01, 2010 11:50 am
PKK,
I'm awaiting my 932's back from Lunds.
Then I am doing the layshaft bearing as well.
I have a 72 combat w/ now 9900 miles on the clock.
I have no reason knowing the history of this bike doubting the miles are true/correct.
This being said and all the failures reported no sense ruining a great bike over a $5.00 bearing.
I contacted a local bearing distributor and got an exact replacement 6203 c-3 for a little over $5.00.
I have not experienced bearing failure YET!!!
You can go roller or ball type bearing.
It's not a big job to shim the roller bearings end play per this forum.
Just avoid binding of the shaft and kickerbush is all you are trying to accomplish there.
I'm a Sunday solo rider so by the time the bike has an additional 12,000 miles it may very well be my sons.
I went OEM ball bearing w/ stainless steel cage as thats what was called for.
I don't race so I don't need a heavy duty mk 19 bullet proof roller type w/ kevlar reinforced jacket.
It's you call check forum for how to do it its covered.
Oldbritts.com has an excellent how to in the tech section of their site
I'm over do as well so no sense taking a chance.
Marshal
I'm awaiting my 932's back from Lunds.
Then I am doing the layshaft bearing as well.
I have a 72 combat w/ now 9900 miles on the clock.
I have no reason knowing the history of this bike doubting the miles are true/correct.
This being said and all the failures reported no sense ruining a great bike over a $5.00 bearing.
I contacted a local bearing distributor and got an exact replacement 6203 c-3 for a little over $5.00.
I have not experienced bearing failure YET!!!
You can go roller or ball type bearing.
It's not a big job to shim the roller bearings end play per this forum.
Just avoid binding of the shaft and kickerbush is all you are trying to accomplish there.
I'm a Sunday solo rider so by the time the bike has an additional 12,000 miles it may very well be my sons.
I went OEM ball bearing w/ stainless steel cage as thats what was called for.
I don't race so I don't need a heavy duty mk 19 bullet proof roller type w/ kevlar reinforced jacket.
It's you call check forum for how to do it its covered.
Oldbritts.com has an excellent how to in the tech section of their site
I'm over do as well so no sense taking a chance.
Marshal
Stings Like A Bee!
-
MarshalNorton - Posts: 566
- Joined: Fri Jan 30, 2009 12:14 pm
- Location: Horsham, PA USA
Re: Good News, Bad News, and Really Bad News!
by comnoz » Wed Sep 01, 2010 12:09 pm
Quote;
It's not a big job to shim the roller bearings end play per this forum.
There is no need to shim the roller bearing. There is no way to control the end play of the layshaft and it does not need control as there is no thrust applied. If you were to shim it on the left side there is still no stop on the right side unless you call the end of the splines butting up against the end of the kick-shaft bushing a wear surface. The ball bearing does not really control the end play either. It has no snap ring to locate it on the shaft and the fit is not tight enough to keep it from ending up where-ever it stops. Nor is the ball bearing retained in the case. When the case is at operating temperature the bearing is barely if at all gripped by the housing. I am not sure who determined that the layshaft rollers need to be shimmed but it was not Norton. I have installed countless roller bearings on the layshaft and have never shimmed one yet. Jim
It's not a big job to shim the roller bearings end play per this forum.
There is no need to shim the roller bearing. There is no way to control the end play of the layshaft and it does not need control as there is no thrust applied. If you were to shim it on the left side there is still no stop on the right side unless you call the end of the splines butting up against the end of the kick-shaft bushing a wear surface. The ball bearing does not really control the end play either. It has no snap ring to locate it on the shaft and the fit is not tight enough to keep it from ending up where-ever it stops. Nor is the ball bearing retained in the case. When the case is at operating temperature the bearing is barely if at all gripped by the housing. I am not sure who determined that the layshaft rollers need to be shimmed but it was not Norton. I have installed countless roller bearings on the layshaft and have never shimmed one yet. Jim
No Carbs
"If the facts don't fit the theory, change the facts." Einstein
You're never too old, to learn something stupid.
"If the facts don't fit the theory, change the facts." Einstein
You're never too old, to learn something stupid.
- comnoz
- Posts: 1678
- Joined: Wed Dec 10, 2008 10:28 pm
- Location: Pueblo Co.
Re: Good News, Bad News, and Really Bad News!
by swooshdave » Wed Sep 01, 2010 12:19 pm
comnoz wrote:Quote;
It's not a big job to shim the roller bearings end play per this forum.
There is no need to shim the roller bearing. There is no way to control the end play of the layshaft and it does not need control as there is no thrust applied. If you were to shim it on the left side there is still no stop on the right side unless you call the end of the splines butting up against the end of the kick-shaft bushing a wear surface. The ball bearing does not really control the end play either. It has no snap ring to locate it on the shaft and the fit is not tight enough to keep it from ending up where-ever it stops. Nor is the ball bearing retained in the case. When the case is at operating temperature the bearing is barely if at all gripped by the housing. I am not sure who determined that the layshaft rollers need to be shimmed but it was not Norton. I have installed countless roller bearings on the layshaft and have never shimmed one yet. Jim
Fred from Old Britts says (underline is mine):
http://www.oldbritts.com/gearbox_a.html
When using the roller bearing (06-7710) for the layshaft, the layshaft is allowed to float, so the end play needs to be checked. You check the amount of end play by using a dial indicator as shown in the following picture. Zero end play will lock up the gears and too much end play will make for sloppy meshing between gears. I try to have around .005" to .010" end play. The end play will grow slightly when the gearbox heats up during riding, so the .005" is a good value to try to obtain.
Now I would never want to tell Jim anything about how to put a Norton together, I just followed what Fred said. When I did my box I did shim it just in case. If it doesn't do any good at least I hope it doesn't do any harm.
You probably want to go into town, and find a up to date Jap Bike store,
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
-
swooshdave - Posts: 6044
- Joined: Wed Apr 15, 2009 10:53 pm
- Location: Portland, Oregon
Re: Good News, Bad News, and Really Bad News!
by ludwig » Wed Sep 01, 2010 12:37 pm
Exessive end play will increase the risk of jumping out of first gear .
Remember the rules ..
- ludwig
- Posts: 1200
- Joined: Wed Aug 30, 2006 3:57 am
Re: Good News, Bad News, and Really Bad News!
by comnoz » Wed Sep 01, 2010 12:56 pm
If the kicker shaft is too far to the right it will increase the tendency for the bike to pop out of first gear , adding shims to the left end of the layshaft will not help as the gear still floats on the shaft. To help first gear you need to install a shim between the inner case and the kicker shaft to move the kicker shaft and first gear to the left . That gives deeper engagement with the sliding gear which is being located by the shift fork.
Jim
PS I am just trying to help with what I have learned and I certainly may be wrong. So I won't be offended if someone tells me I am full of shit. But we will then have to determine the right way.
Jim
PS I am just trying to help with what I have learned and I certainly may be wrong. So I won't be offended if someone tells me I am full of shit. But we will then have to determine the right way.
No Carbs
"If the facts don't fit the theory, change the facts." Einstein
You're never too old, to learn something stupid.
"If the facts don't fit the theory, change the facts." Einstein
You're never too old, to learn something stupid.
- comnoz
- Posts: 1678
- Joined: Wed Dec 10, 2008 10:28 pm
- Location: Pueblo Co.
Re: Good News, Bad News, and Really Bad News!
by gjr » Wed Sep 01, 2010 1:01 pm
I'm riding out to my folks house and pulling away from a stop sign I feel something brush my calf. Shift into second, wind on some throttle and the kickstart lever moves back. I had put the roller layshaft bearing in a few years ago and it was still in there when I looked this winter.
Are the roller (Norvil 'Superblend') really fit it and forget it, or do they go bad ? If it is not the bearing what could it be (I didn't shim it either).
Greg
Are the roller (Norvil 'Superblend') really fit it and forget it, or do they go bad ? If it is not the bearing what could it be (I didn't shim it either).
Greg
-
gjr - Posts: 199
- Joined: Fri Mar 05, 2010 4:47 pm
- Location: Delano. Minnesota
Re: Good News, Bad News, and Really Bad News!
by swooshdave » Wed Sep 01, 2010 1:03 pm
comnoz wrote:To help first gear you need to install a shim between the inner case and the kicker shaft to move the kicker shaft and first gear to the left . That gives deeper engagement with the sliding gear which is being located by the shift fork.
Jim
That is the way Fred shims it.
You probably want to go into town, and find a up to date Jap Bike store,
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
-
swooshdave - Posts: 6044
- Joined: Wed Apr 15, 2009 10:53 pm
- Location: Portland, Oregon
Re: Good News, Bad News, and Really Bad News!
by ludwig » Wed Sep 01, 2010 1:06 pm
comnoz wrote:I.. To help first gear you need to install a shim between the inner case and the kicker shaft to move the kicker shaft and first gear to the left ..
Of course ! ..I always tought that this was self evident ..
Remember the rules ..
- ludwig
- Posts: 1200
- Joined: Wed Aug 30, 2006 3:57 am
Re: Good News, Bad News, and Really Bad News!
by swooshdave » Wed Sep 01, 2010 1:11 pm
ludwig wrote:comnoz wrote:I.. To help first gear you need to install a shim between the inner case and the kicker shaft to move the kicker shaft and first gear to the left ..
Of course ! ..I always tought that this was self evident ..
But they weren't shimmed from the factory with the roller bearings.
You probably want to go into town, and find a up to date Jap Bike store,
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
With a full spares department, a clean workshop, and kean young mechanics.
And ask them if theres a Grumpy Old Bloke out in the Hills, who knows how to fix Real Motorcycles.
Matt
-
swooshdave - Posts: 6044
- Joined: Wed Apr 15, 2009 10:53 pm
- Location: Portland, Oregon
Re: Good News, Bad News, and Really Bad News!
by tpeever » Wed Sep 01, 2010 1:13 pm
kommando wrote:The cause of this issue coming to surface was the introduction of the 850, the gearing was taller plus the engine gave extra torque which increased the loading on the gearbox. That plus a batch of duff bearings from Portugal made it a epidemic. Mine was on a 850 MK2a and had the Portugese bearing, so its not just on the MK3's.
Ditto. I have a MkIIa and my layshaft bearing went at 10K miles. It was the Portuguese bearing. Fortunately for me, the bearing cage gave out at about 10 mph and nothing dramatic happened other than a loud clunk. Kickstarter started dancing and dropping down about 1 minute before the clunk. I was even able to drive it home 8 miles without causing any damage.
74 Commando
61 Dominator 88
47 ES2
Assorted vintage British and Italian
61 Dominator 88
47 ES2
Assorted vintage British and Italian
- tpeever
- Posts: 585
- Joined: Mon Aug 21, 2006 8:54 pm
- Location: Pullman, WA, USA
Re: Good News, Bad News, and Really Bad News!
by tpeever » Wed Sep 01, 2010 1:14 pm
swooshdave wrote:But they weren't shimmed from the factory with the roller bearings.
I think that's because rollers were never fitted from the factory. Rollers can't control endplay of the layshaft so need to be shimmed.
74 Commando
61 Dominator 88
47 ES2
Assorted vintage British and Italian
61 Dominator 88
47 ES2
Assorted vintage British and Italian
- tpeever
- Posts: 585
- Joined: Mon Aug 21, 2006 8:54 pm
- Location: Pullman, WA, USA
Return to Norton Commando Motorcycles.
Who is online
Users browsing this forum: Google [Bot] and 0 guests