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+---- Thread: Another Loose Sprocket Nut (/showthread.php?tid=33450)
Another Loose Sprocket Nut - slartybartfarst - 29-06-2008
Is loose nuts just a Mk1 problem [img]style_emoticons/<#EMO_DIR#>/happy.gif[/img] ? Or does the 'get a genuine front sprocket' follow for all?
I only ask because mine needs chain and sprockets. The character I'm going too for the service (Mr Pig in Manchester) tells me he will only fit top quality stuff. But it sounds like it might be best if I make sure he uses a genuine front sprocket and the Loctite - though this will doubtless generate one of his pithy remarks!
I'm guessing the Yam C&S kit isn't cheap and am I right in thinking it's not an x-ring chain?
Slarty
(My grandmother is now for sale to pay for the service!)
Another Loose Sprocket Nut - lemonentrails - 29-06-2008
<!--quoteo(post=89358:date=Sun 29th Jun 2008, 11:29 PM:name=slartybartfarst)-->QUOTE(slartybartfarst @ Sun 29th Jun 2008, 11:29 PM) <{POST_SNAPBACK}><!--quotec-->Is loose nuts just a Mk1 problem [img]style_emoticons/<#EMO_DIR#>/happy.gif[/img] ? Or does the 'get a genuine front sprocket' follow for all?
I only ask because mine needs chain and sprockets. The character I'm going too for the service (Mr Pig in Manchester) tells me he will only fit top quality stuff. But it sounds like it might be best if I make sure he uses a genuine front sprocket and the Loctite - though this will doubtless generate one of his pithy remarks!
I'm guessing the Yam C&S kit isn't cheap and am I right in thinking it's not an x-ring chain?
Slarty
(My grandmother is now for sale to pay for the service!)<!--QuoteEnd--><!--QuoteEEnd-->
I've run JT sprox and loctited the nut fer years and never had a problem
Lem
Another Loose Sprocket Nut - wicklamulla - 30-06-2008
<!--quoteo(post=89364:date=Mon 30th Jun 2008, 12:01 AM:name=lemonentrails)-->QUOTE(lemonentrails @ Mon 30th Jun 2008, 12:01 AM) <{POST_SNAPBACK}><!--quotec-->I've run JT sprox and loctited the nut fer years and never had a problem
Lem<!--QuoteEnd--><!--QuoteEEnd-->
that good to know as it restores my faith in JT sprox kits. But why were you loctit'n the nut in the first place, cos it kept coming loose or were you just using the belt and braces approach ???
Another Loose Sprocket Nut - TonyDevil - 30-06-2008
<!--quoteo(post=89358:date=Sun 29th Jun 2008, 11:29 PM:name=slartybartfarst)-->QUOTE(slartybartfarst @ Sun 29th Jun 2008, 11:29 PM) <{POST_SNAPBACK}><!--quotec-->I'm guessing the Yam C&S kit isn't cheap and am I right in thinking it's not an x-ring chain?<!--QuoteEnd--><!--QuoteEEnd-->
yammie front sprocket
did x/o ring chain
after market rear sprocket
dont buy all yammie, not needed [img]style_emoticons/<#EMO_DIR#>/good.gif[/img]
i also wouldnt spend the extra on x-ring, o-ring is more than enough [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]
Another Loose Sprocket Nut - wicklamulla - 30-06-2008
i agree with wot him above says.
Another Loose Sprocket Nut - lemonentrails - 30-06-2008
<!--quoteo(post=89371:date=Mon 30th Jun 2008, 03:23 AM:name=wicklamulla)-->QUOTE(wicklamulla @ Mon 30th Jun 2008, 03:23 AM) <{POST_SNAPBACK}><!--quotec-->that good to know as it restores my faith in JT sprox kits. But why were you loctit'n the nut in the first place, cos it kept coming loose or were you just using the belt and braces approach ???<!--QuoteEnd--><!--QuoteEEnd-->
old habit picked up from running and working on brit bikes! they have tab washers too but nuts still loosen off,I guess its a mistrust off tab washers.
Another Loose Sprocket Nut - dapleb - 04-07-2008
<!--quoteo(post=89294:date=Sun 29th Jun 2008, 05:15 PM:name=GuyGraham)-->QUOTE(GuyGraham @ Sun 29th Jun 2008, 05:15 PM) <{POST_SNAPBACK}><!--quotec-->A properly torqued nut will never jump a thread - I can guarantee that if it has, then it was loose to begin with<!--QuoteEnd--><!--QuoteEEnd-->
Always correclty torqued, so guess it hasnt moved on the threads and that something else has moved!
<!--quoteo(post=89294:date=Sun 29th Jun 2008, 05:15 PM:name=GuyGraham)-->QUOTE(GuyGraham @ Sun 29th Jun 2008, 05:15 PM) <{POST_SNAPBACK}><!--quotec-->full explanation [url="http://www.carpe-tdm.net/ipb/index.php?showtopic=6327"]here[/url<!--QuoteEnd--><!--QuoteEEnd-->
Since I am totally certain of the correct torque being applied, this seems like the only possible explanation given that the nut (though loose) has not moved on the threads!
Have got new AFAM sprock and nut/tab to fit and will mark everything so in the unlikely event of anything moving with the Loctite 638 oi will know what it were!
Another Loose Sprocket Nut - dapleb - 05-07-2008
Dug up an old orig Yam sprock (from mkII), me old and worn AFAM sprock, the one that has just been removed (unbranded and not worn) and me new AFAM sprock.
Yamaha and AFAM (old and new) are a much better fit on the splines than the troublesome one that I have just removed. There is no difference between the Yam and AFAM on my splines....so I'll be paying £9 a go rather than £45!
Sprock is now loctited on.....hope I put enough on. [img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]
Another Loose Sprocket Nut - Guest - 05-07-2008
<!--quoteo(post=90085:date=Sat 5th Jul 2008, 07:48 AM:name=dapleb)-->QUOTE(dapleb @ Sat 5th Jul 2008, 07:48 AM) <{POST_SNAPBACK}><!--quotec-->Dug up an old orig Yam sprock (from mkII), me old and worn AFAM sprock, the one that has just been removed (unbranded and not worn) and me new AFAM sprock.
Yamaha and AFAM (old and new) are a much better fit on the splines than the troublesome one that I have just removed. There is no difference between the Yam and AFAM on my splines....so I'll be paying £9 a go rather than £45!
Sprock is now loctited on.....hope I put enough on. [img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->
It really don't need alot - just enough to fill in the gaps between the splines on the shaft and the sporcket, which is only a very small gap 0.1-0.2mm max
the DRZ boys (where the fix originated) say only 3 drops on the output shaft required
I put a drop in each valley of the splines on the shaft, and a drop in each valley of the splines in the sprocket, and assemble
Too much and you risk pushing it under the output shaft oil seal spacer, and loctiting that in place!!!!
3 times I have change the sprocket on me DRZ and each time it has required the 3 legged puller to get it off.
Its good stuff I tell you
You just need to make sure its spotlessly clean
Use contact cleaner to remove any oil/chain lube etc and fine wet & dry to remove any rust, they contact cleaner again.
Another Loose Sprocket Nut - lemonentrails - 05-07-2008
<!--quoteo(post=90085:date=Sat 5th Jul 2008, 07:48 AM:name=dapleb)-->QUOTE(dapleb @ Sat 5th Jul 2008, 07:48 AM) <{POST_SNAPBACK}><!--quotec--><!--quoteo--><div class='quotetop'>QUOTE<!--quotec-->Dug up an old orig Yam sprock (from mkII), me old and worn AFAM sprock, the one that has just been removed (unbranded and not worn) and me new AFAM sprock.<!--QuoteEnd--><!--QuoteEEnd-->
<!--coloro:#FF0000--><!--/coloro-->A manufacturer that's proud of their product will put a name on it!<!--colorc-->
<!--/colorc-->
Yamaha and AFAM (old and new) are a much better fit on the splines than the troublesome one that I have just removed. There is no difference between the Yam and AFAM on my splines....so I'll be paying £9 a go rather than £45!
<!--quoteo-->QUOTE<!--quotec-->Sprock is now loctited on.....hope I put enough on. :unsure<!--QuoteEnd--><!--QuoteEEnd-->:
<!--QuoteEnd--></div><!--QuoteEEnd-->
<!--coloro:#FF0000--><!--/coloro-->You will have , I find spreading it on with my fingers so it just coats t' freds on't nut n shaft usually works.<!--colorc-->
<!--/colorc-->
Another Loose Sprocket Nut - Guest - 05-07-2008
<!--quoteo(post=90103:date=Sat 5th Jul 2008, 10:19 AM:name=lemonentrails)-->QUOTE(lemonentrails @ Sat 5th Jul 2008, 10:19 AM) <{POST_SNAPBACK}><!--quotec--><!--coloro:#FF0000--><!--/coloro-->You will have , I find spreading it on with my fingers so it just coats t' freds on't nut n shaft usually works.<!--colorc-->
<!--/colorc--><!--QuoteEnd--><!--QuoteEEnd-->
Not required on the threads - tab washer will hold nut in place
Re-read this thread
Loose sprocket syndrome has nothing to do with the nut coming undone, as the nut doesn't move
Another Loose Sprocket Nut - lemonentrails - 05-07-2008
<!--quoteo(post=90108:date=Sat 5th Jul 2008, 11:00 AM:name=GuyGraham)-->QUOTE(GuyGraham @ Sat 5th Jul 2008, 11:00 AM) <{POST_SNAPBACK}><!--quotec-->Not required on the threads - tab washer will hold nut in place
Re-read this thread
Loose sprocket syndrome has nothing to do with the nut coming undone, as the nut doesn't move<!--QuoteEnd--><!--QuoteEEnd-->
I dont agree with your assumptions,so will keep loctiting the nut only and continue to have a tight sprocket!
Another Loose Sprocket Nut - dapleb - 05-07-2008
<!--quoteo(post=90109:date=Sat 5th Jul 2008, 11:04 AM:name=lemonentrails)-->QUOTE(lemonentrails @ Sat 5th Jul 2008, 11:04 AM) <{POST_SNAPBACK}><!--quotec-->I dont agree with your assumptions<!--QuoteEnd--><!--QuoteEEnd-->
How do you explain a 'loose' nut that it still tabbed to a shaft? I can't see another way for this to happen.
Another Loose Sprocket Nut - Guest - 05-07-2008
<!--quoteo(post=90109:date=Sat 5th Jul 2008, 11:04 AM:name=lemonentrails)-->QUOTE(lemonentrails @ Sat 5th Jul 2008, 11:04 AM) <{POST_SNAPBACK}><!--quotec-->I dont agree with your assumptions,so will keep loctiting the nut only and continue to have a tight sprocket!<!--QuoteEnd--><!--QuoteEEnd-->
you haven't understood the problem
i stress again re-read this thread, and do a search about it
The nut doesn't come undone - its a loss of clamping pressure which gives the impression of the nut having come undo, but it hasn't actually moved
You carry on loctiting the nut only - Your bike, your choice.
Another Loose Sprocket Nut - lemonentrails - 05-07-2008
<!--quoteo(post=90110:date=Sat 5th Jul 2008, 11:11 AM:name=dapleb)-->QUOTE(dapleb @ Sat 5th Jul 2008, 11:11 AM) <{POST_SNAPBACK}><!--quotec-->How do you explain a 'loose' nut that it still tabbed to a shaft? I can't see another way for this to happen.<!--QuoteEnd--><!--QuoteEEnd-->
This is what i think/know/summise having seen the same problem on many other bikes using this method of locking
The constant back and forth shocks from the drive train loading and unloading (a bit like the way an air impact wrench works) causes the tab's splines to wear a minute amount which builds up over time to the point where loosening the nut is inevitable. Have a close look at an old tab whasher. Agreed if the nut is torqued up to the correct torque using perfect threads this is less likely to happen. But how often is this the case in the real world where access to torque wrenches is not always available and the ability to lock the shaft well enough so the required torque can be applied is not there.
Just my thoughts and experience of working with bikes for 20 odd years.
Another Loose Sprocket Nut - dapleb - 05-07-2008
<!--quoteo(post=90114:date=Sat 5th Jul 2008, 11:40 AM:name=lemonentrails)-->QUOTE(lemonentrails @ Sat 5th Jul 2008, 11:40 AM) <{POST_SNAPBACK}><!--quotec-->Have a close look at an old tab whasher.<!--QuoteEnd--><!--QuoteEEnd-->
Booger shoulda compared to the newy before install. The oldy doesn't look worn, but its zummat I hadn't thought about and we are only talkin bout a tiny change to cause this looseyness. I put normal loctite on tut nut too so hopefully whatever the cause is, it will not occur!
Another Loose Sprocket Nut - lemonentrails - 05-07-2008
<!--quoteo(post=90113:date=Sat 5th Jul 2008, 11:17 AM:name=GuyGraham)-->QUOTE(GuyGraham @ Sat 5th Jul 2008, 11:17 AM) <{POST_SNAPBACK}><!--quotec-->You carry on loctiting the nut only - Your bike, your choice.<!--QuoteEnd--><!--QuoteEEnd-->
sure is!
been doin it fer 14 yrs of tdm ownership and on other bikes and it works fer me!
Another Loose Sprocket Nut - Guest - 05-07-2008
look at the microfiche below of the TDM 3VD transmission
You see the 2nd gear bushing (part of group of items labeled as '15'
![[Image: 3vdtrans.jpg]](http://i10.photobucket.com/albums/a120/guygraham/3vdtrans.jpg)
when you torque up the nut, it clamps against the sprocket, which clamps against the oil seal spacer, which clamps against the bearing inner race, which clamps against the second gear bushing, which clamps against the shoulder on the outputshaft and hence everything is clamped up tight
The constant back and forth shocks as lemonentrails quite rightly points out from the acceleration and deceleration, makes the sprocket rock back and forth. Where lemonentrials is wrong is assuming this wear takes place in the splines and loosens the nut
This is the second gear bushing from my DRZ400S, which has the same transmission set up, and also suffers from loosening front sprockets. Mine came loose twice, despite being torqued to the correct figure of 70Nm
![[Image: IMG_1267.jpg]](http://i10.photobucket.com/albums/a120/guygraham/IMG_1267.jpg)
See that groove on the outer face, thats where the inner race of the bearing clamps against it, and when tight, spins with the bearing and shaft.
As the bearing is harder than the bushing, the bushing wears, and hence causes the loss of clamping press without the nut ever actually moving.
Now, it may be the second gear bushing that wears on the TDM, or it maybe something else, as I have not examined the parts from a bike on which the sprocket has been loose, but the key to stopping the wear, and hence stopping the loose sprocket is to stop the sprocket from rocking back and forth.
The pressure applied by the sprocket nut is not enough to do this, else they wouldn't come 'loose'. This is why you need the loctite on the splines, to prevent this movement.
Ordinary blue thread lock, or Loctite Stud'n'Bearing (red) is not strong enough (I know, it failed to do the job twice on my DRZ) , but Locitie 638 most certainly is
Another Loose Sprocket Nut - Guest - 05-07-2008
<!--quoteo(post=90123:date=Sat 5th Jul 2008, 01:12 PM:name=lemonentrails)-->QUOTE(lemonentrails @ Sat 5th Jul 2008, 01:12 PM) <{POST_SNAPBACK}><!--quotec-->sure is!
been doin it fer 14 yrs of tdm ownership and on other bikes and it works fer me!<!--QuoteEnd--><!--QuoteEEnd-->
Not all other bike have this set up
Many bikes have the shoulder on the output shaft directly behind the the gearbox sprocket bearing and hence the 2nd gear bushing is isolating from the pressure / rocking movement - these bikes never have the sprocket come 'loose'
I glad its never come loose for you in 14 years, but there are quite a few on here, for whom they have, and for some of those it has trashed their output shaft.
Another Loose Sprocket Nut - dapleb - 05-07-2008
<!--quoteo(post=90124:date=Sat 5th Jul 2008, 01:31 PM:name=GuyGraham)-->QUOTE(GuyGraham @ Sat 5th Jul 2008, 01:31 PM) <{POST_SNAPBACK}><!--quotec-->The constant back and forth shocks as lemonentrails quite rightly points out from the acceleration and deceleration, makes the sprocket rock back and forth.<!--QuoteEnd--><!--QuoteEEnd-->
Aided by shitey fitting aftermarket sprocks. My bike has never had any looseyness until I fitted the unbranded bugger.
I will strip doon one of me garden ornaments at some point and see if there is any wear to any of the components atween the clamping faces on the shaft.