Been experiencing grinding sounds in the chain department and a quiet knock on corners; thinking it related to the winter road crap and salt (how much lube do I have to throw at this not year old chain ffs) I figure a clean is in order.
Removed the front cover, loads of crap around the front sprocket so the scoop out begins and suddenly once enough crud is removed to my horror the the sprocket wobbles.
The new wider nut has come off. I found the lock washer down below which had been bent round the nut as required
but some how flattened off.
I replaced the chain and sprocket in May, torqued correctly (imo) to the spec suggested for wider nut.
Women have chocolate men have bikes.....
including ones who like chocolate....
28-01-17, 04:55 PM (This post was last modified: 28-01-17, 05:03 PM by tommyardin.)
[size=1em]I have heard that some folk are only tightening the nut up to 75Nm to 80Nm, Yamaha are recommending 90Nm with the new 12mm nut, and fit a new tab washer at the same time.
Yamaha are also recommending the use of Loctite, ensuring the new nut and the thread on the output shaft are thoroughly cleaned before applying Loctite and tightening up to 90Nm.
Bending the tab washer over 2 of the 12mm nut flats
The original torque was 70 Nm with the 9mm nut, and guys are worried that 90Nm will strip their output shaft threads.
I did not have Loctite but mine went up to the recommended 90Nm and I used nail varnish on the nut and thread in place of Loctite.
Have you ever tried to unscrew the top of a nail varnish bottle for the Mrs or G/F when it had nail varnish left on the thread of the bottle top, it's often pliers on the top and smashing the top to bits in the process.[/size]
[size=1em]
I'm guessing if you go your own way with your own ideas when it comes to tightening the nut up there really is no come back, but saying that I used nail varnish/polish not Loctite, so be it on my own head. [/size]
[size=1em]Quick edit:[/size]
[size=1em]Ensure that the cut outs on the tab washer are pushed right into the clean splines of the output shaft if they are not the tab washer can spin with the nut and not be lined up with the splines then the tab washer will do absolutely nothing.[/size]
It's best to remove the front sprocket and clean thoroughly behind the sprocket and the sprocket itself otherwise you might just be tightening up on shit, and not have a face to face metal to metal contact to torque up to.
(28-01-17, 04:55 PM)tommyardin link Wrote: [size=1em]I have heard that some folk are only tightening the nut up to 75Nm to 80Nm, Yamaha are recommending 90Nm with the new 12mm nut, and fit a new tab washer at the same time.
Yamaha are also recommending the use of Loctite, ensuring the new nut and the thread on the output shaft are thoroughly cleaned before applying Loctite and tightening up to 90Nm.
Bending the tab washer over 2 of the 12mm nut flats
The original torque was 70 Nm with the 9mm nut, and guys are worried that 90Nm will strip their output shaft threads.
I did not have Loctite but mine went up to the recommended 90Nm and I used nail varnish on the nut and thread in place of Loctite.
Have you ever tried to unscrew the top of a nail varnish bottle for the Mrs or G/F when it had nail varnish left on the thread of the bottle top, it's often pliers on the top and smashing the top to bits in the process.[/size]
[size=1em]
I'm guessing if you go your own way with your own ideas when it comes to tightening the nut up there really is no come back, but saying that I used nail varnish/polish not Loctite, so be it on my own head. [/size]
[size=1em]Quick edit:[/size]
[size=1em]Ensure that the cut outs on the tab washer are pushed right into the clean splines of the output shaft if they are not the tab washer can spin with the nut and not be lined up with the splines then the tab washer will do absolutely nothing.[/size]
[size=1em]It's best to remove the front sprocket and clean thoroughly behind the sprocket and the sprocket itself otherwise you might just be tightening up on shit, and not have a face to face metal to metal contact to torque up to.[/size]
all good advice what i would say is it couldnt have torqued properly and the lock washer couldnt have been on right to cause it to come off
Yes agree good advice Daviee. Something was clearly amiss, there isn't much shaft left for the tab washer to sit.
Perhaps I did fit it wrong even following instructions.
That said, my original nut never came loose so perhaps there was never a problem other than the Yamaha mechanic fitted some nuts incorrectly
Women have chocolate men have bikes.....
including ones who like chocolate....
(28-01-17, 09:06 PM)Frosties link Wrote: Also agree it's good advice from Tomski :look ...................................it's a bloody first for him but at least it's a start :lol .
(28-01-17, 05:11 PM)daviee link Wrote: [quote author=tommyardin link=topic=21736.msg250990#msg250990 date=1485618902]
[size=1em]I have heard that some folk are only tightening the nut up to 75Nm to 80Nm, Yamaha are recommending 90Nm with the new 12mm nut, and fit a new tab washer at the same time.
Yamaha are also recommending the use of Loctite, ensuring the new nut and the thread on the output shaft are thoroughly cleaned before applying Loctite and tightening up to 90Nm.
Bending the tab washer over 2 of the 12mm nut flats
The original torque was 70 Nm with the 9mm nut, and guys are worried that 90Nm will strip their output shaft threads.
I did not have Loctite but mine went up to the recommended 90Nm and I used nail varnish on the nut and thread in place of Loctite.
Have you ever tried to unscrew the top of a nail varnish bottle for the Mrs or G/F when it had nail varnish left on the thread of the bottle top, it's often pliers on the top and smashing the top to bits in the process.[/size]
[size=1em]
I'm guessing if you go your own way with your own ideas when it comes to tightening the nut up there really is no come back, but saying that I used nail varnish/polish not Loctite, so be it on my own head. [/size]
[size=1em]Quick edit:[/size]
[size=1em]Ensure that the cut outs on the tab washer are pushed right into the clean splines of the output shaft if they are not the tab washer can spin with the nut and not be lined up with the splines then the tab washer will do absolutely nothing.[/size]
[size=1em]It's best to remove the front sprocket and clean thoroughly behind the sprocket and the sprocket itself otherwise you might just be tightening up on shit, and not have a face to face metal to metal contact to torque up to.[/size]
all good advice what i would say is it couldnt have torqued properly and the lock washer couldnt have been on right to cause it to come off
[/quote]
Daviee when you retrieved the Tab Washer after it had come off, were the sides still bent up in the locked position? if they were then I think the washer was never located properly.
28-01-17, 11:22 PM (This post was last modified: 28-01-17, 11:23 PM by tommyardin.)
Daviee when you retrieved the Tab Washer after it had come off, were the sides still bent up in the locked position? if they were then I think the washer was never located properly.
[color=rgb(51, 68, 102)]
Edit: Midden when you retrieved the Tab Washer after it had come off, were the sides still bent up in the locked position? if they were then I think the washer was never located properly.
29-01-17, 01:19 PM (This post was last modified: 29-01-17, 01:24 PM by fazersharp.)
Nail varnish as a thread lock - it may work but I would of thought that it is too brittle whereas the locktite I believe has bit of elasticity with it.
I have some blue locktite but that is not the recommended one read it all here http://foc-u.co.uk/index.php?topic=14924.0
The recommended one is 620 and is very expensive
I don't do rain or threat there of. dry rider only with no shame.
29-01-17, 02:54 PM (This post was last modified: 29-01-17, 02:57 PM by tommyardin.)
(29-01-17, 01:19 PM)fazersharp link Wrote: Nail varnish as a thread lock - it may work but I would of thought that it is too brittle whereas the locktite I believe has bit of elasticity with it.
I have some blue locktite but that is not the recommended one read it all here http://foc-u.co.uk/index.php?topic=14924.0
The recommended one is 620 and is very expensive
Cheers Sharpie,
I just read the posts in the link you put up.
So many people are saying don't tighten the nut up to 90Nm and don't use Loctite, how come so many guys know so much more that Yamaha do about a piece of machinery that Yamaha designed and produced.
It seems the Butcher The Baker and The Candlestick makers are all qualified to help you fuck up you motorcycle, by giving you their knowledgeable and poor thought out opinions and reasons.
I think I will listen to Yamaha and their expert advice and give Brian who works in the kitchen department at B&Q a miss.
If I want to know about kitchen taps I will ask Brian, because Yamaha know fuck all about kitchen taps.
I have a new front sprocket to go on my old girl in the next week or so, I have also purchased some Loctite, as I also have not followed Yamaha's advice, because i used nail varnish instead of the proper stuff.
Cleanliness is a thing to remember when fitting the sprocket nut, make sure everything in contact with the nut, washer, sprocket and gearbox face is clean and tighten it up to the recommended torque using the recommended Loctite 620, also check and re-check again that the tab washer is indeed located in the output shaft splines, and double flat the the sides of the tab washer against the nut with a tight snug fit.
I would be a little hesitant about buying this stuff from Hong Kong or China.
Some of the sales of the stuff on evilBay look like they are being sent from Australia as the prices are marked up in Aus $ dollars, but with a closer look they are being posted from China or Hong Kong, seems a bit deceitful to me.
I know there is no real 100% sure-fire way of knowing that you are getting the real stuff, as there is so much fake stuff out their, ranging from Motor products to shampoo.
There is an old saying 'If a deal seems to good to be true>>>>> blah blah blah'
The link above are UK based Seller, their feedback is good and their price seems about normal.
The first picture is ideal, the second picture is a No No, because it will allow the nut to rock/rotate under the immense power of the drive and will slowly hammer the washer flats back down as it snatches as the power goes on, the other thing is use the proper washer and not a bit of thick grey paper like I used. :lol
Am I correct in thinking that it wasn't the original nut and torque spec that was at fault but it was an issue with some of the output shafts being slightly undersized, thus allowing the nut to work free?.
another thought if you are worried about the locking washer spinning you could always tack weld it to the sprocket then it cant possibly rotate , and if your really worried you could tack weld the nut to the sprocket not the shaft then its just a case of when replacing the sprocket you would need to replace the nut aswell or in the first case the lock tab
(29-01-17, 05:53 PM)YamFazFan link Wrote: Am I correct in thinking that it wasn't the original nut and torque spec that was at fault but it was an issue with some of the output shafts being slightly undersized, thus allowing the nut to work free?.
I think I can say that the general consensus is that yes that is the case, and it is the luck of the draw if your shaft is undersized which explains why some have the issue and others not.
My own research and theory points to the first 98 models being unaffected as the shafts were done in 1 factory and then the bike took off and the shafts had to be made in other factories to keep up with demand, then there is a cut off time when the problem was spotted and after that the shafts were in spec and the 12mm nut was issued as a fix instead of swapping the shafts on affected bikes. :lurk
Over the years on this forum not 1 98 bike has had the problem --- with the caveat being that it has to of occurred on a factory fitted nut, so as to rule out a replacement not being correctly fitted. Admittedly a 98 on original sprockets is getting rare although I have one.
I don't do rain or threat there of. dry rider only with no shame.
