Another Loose Sprocket Nut

[TonyDevil]

<!--quoteo(post=47464:date=Mon 16th Jul 2007, 08:43 AM:name=wicklamulla)-->QUOTE(wicklamulla @ Mon 16th Jul 2007, 08:43 AM) <{POST_SNAPBACK}><!--quotec-->ya mines almost flush, looks like the outputshafts are different or the nuts/sprockets we are using.<!--QuoteEnd--><!--QuoteEEnd-->
havent got the TDM here, but i'll get a photo of the TRX and XTZ ones tonight

FFS 03:23 and 08:43 go get some sleep my irish chum

[wicklamulla]

ah sher 5 hours is enuf, oil snooze on the couch with the cats laters.

[Guest]

<!--quoteo(post=47461:date=Mon 16th Jul 2007, 03:23 AM:name=wicklamulla)-->QUOTE(wicklamulla @ Mon 16th Jul 2007, 03:23 AM) <{POST_SNAPBACK}><!--quotec-->well PK, Spongey and meself discussed the front sprocket nut problems on MKI's and XTZ 750's after i proudly proclaimed that i had reused my front nut and tab washer 4 times with great success and the nut still looks perfect, i refitted me front sprocket yesterday and decided to use a brand new nut and washer just to be safe !! PK mentioned that when the nut is torqued up on a MKI there is usually some threads showing on the output shaft ?? is this accurate Tonski and udders ?? well heres a pics of mine fully torqued up past the 70Nm limit with no thread showing (i am using a genuine yam fr. sprocket, nut and tab washer) i also took some measurements & pics of the outputshafts on both my 1999 enjuns if anyone wants them lemme know.

<!--QuoteEnd--><!--QuoteEEnd-->


That aint a Yam sprocket, Wick.
Genuine Yam sprockets have a rubber bushing around the circumference to quieten down chain noise

as I stated in earlier, Mk1 & MkIIa's use the same sprocket, MKII's use a different front sprocket, and hence the shaft must be a different length, coz the MKII sprocket has a thicker section around the splined hole

This post was last modified: 16-07-2007, 05:57 PM by GuyGraham.

[wicklamulla]

mmm i wonder if my MKIIa is fitted with a MKII sprocket cos it came in official yamaha packaging with a part number etc, i'm pretty certain my original fr. sprocket did not have that anti noise bush fitted GG, as i remember the 2 sprocks (old versus new) were identical ?? !! don't suppose someone has a pic please ? either way that sprocket i have fitted seems perfect.

[Guest]

<!--quoteo(post=47578:date=Tue 17th Jul 2007, 12:49 AM:name=wicklamulla)-->QUOTE(wicklamulla @ Tue 17th Jul 2007, 12:49 AM) <{POST_SNAPBACK}><!--quotec-->mmm i wonder if my MKIIa is fitted with a MKII sprocket cos it came in official yamaha packaging with a part number etc, i'm pretty certain my original fr. sprocket did not have that anti noise bush fitted GG, as i remember the 2 sprocks (old versus new) were identical ?? !! don't suppose someone has a pic please ? either way that sprocket i have fitted seems perfect.<!--QuoteEnd--><!--QuoteEEnd-->


Genuine Yam front sprocket for MkII


After market front (JT sprockets), without bushing, but showing boss around the splined hole

[wicklamulla]

good lad GG, well i can now say fer certain that i have never seen a sprocket like yours with the anti noise yoke fitted to my later MKII. wonder if they changed sprocket types from 99 onwards ??

This post was last modified: 18-07-2007, 01:10 AM by wicklamulla.

[Guest]

<!--quoteo(post=47681:date=Wed 18th Jul 2007, 01:16 AM:name=wicklamulla)-->QUOTE(wicklamulla @ Wed 18th Jul 2007, 01:16 AM) <{POST_SNAPBACK}><!--quotec-->good lad GG, well i can now say fer certain that i have never seen a sprocket like yours with the anti noise yoke fitted to my later MKII. wonder if they changed sprocket types from 99 onwards ??<!--QuoteEnd--><!--QuoteEEnd-->

Yes Wick

MkIIa use same front sprocket as MkI which is diff to the MkII (96-98), although I am very surprised about the rubber bushing around the outside as its a trick all the manufacturers use to quieten down noise form the chain and sprockets in order to get it through the noise tests (even my DRZ has it on the OE sprocket)

Both my MkII's have had the front sprocket with rubber bushing on the original sprocket

This post was last modified: 18-07-2007, 11:51 AM by GuyGraham.

[dapleb]

Well I checked me front sprock today after much naggin from Wickywoo and it was very sightly loose....but still retained by the tab washer! It was like this once before after me E.Europe trip but has been fine since then!

Not wanting to join the knackered output shaft club, I thought oid get a new front sprock from Yamahahaha....as Chris mentioned......near enough £50 squids, that ain't gonna happen!!!!!! So, I ordered a new nut n washer and 3ml (enough?) of Loctitie 638.

Chris, you still had some problems even after you used the 638?

From what GG describes this is applied between sprock and shaft to remove the play? You are applying this stuff to the shaft where the nut sits and then holding it in place to set by doing up the nut?

b0o0o0o0op

[Guest]

<!--quoteo(post=89168:date=Sat 28th Jun 2008, 03:17 PM:name=dapleb)-->QUOTE(dapleb @ Sat 28th Jun 2008, 03:17 PM) <{POST_SNAPBACK}><!--quotec-->Well I checked me front sprock today after much naggin from Wickywoo and it was very sightly loose....but still retained by the tab washer! It was like this once before after me E.Europe trip but has been fine since then!

Not wanting to join the knackered output shaft club, I thought oid get a new front sprock from Yamahahaha....as Chris mentioned......near enough £50 squids, that ain't gonna happen!!!!!! So, I ordered a new nut n washer and 3ml (enough?) of Loctitie 638.<!--QuoteEnd--><!--QuoteEEnd-->

3ml is plenty to do 1 bike

<!--quoteo(post=89168:date=Sat 28th Jun 2008, 03:17 PM:name=dapleb)-->QUOTE(dapleb @ Sat 28th Jun 2008, 03:17 PM) <{POST_SNAPBACK}><!--quotec-->Chris, you still had some problems even after you used the 638?

From what GG describes this is applied between sprock and shaft to remove the play? You are applying this stuff to the shaft where the nut sits and then holding it in place to set by doing up the nut?

b0o0o0o0op<!--QuoteEnd--><!--QuoteEEnd-->

A drop in each 'valley' on the shaft, and a drop in each 'valley' in the splines on the sprocket
Assemble and torque up
Wait 24hrs (most important)

Buy 3 legged puller when removal required (believe me you will need it if you've done it right)
Remember to clean the shaft with brake/contact cleaner

[dapleb]

Thanks GG.

Bugger the 24 hours wait ain't good as I want to be on it and on me way to Oirleland!!

Sprocket and shaft all cleaned up and waiting (wire brush, brake cleaner and emery'd)

Yeah I read bout 3 legged pullers, plenty of em aroond ear.

Need to go and re-read your theory about all this GG as I understand how wear to the internal shoulder would allow the sprocket to become loose but don't understand how for some the nut seems to have moved on the threads, or is that not the case?

[aircooled68]

mine still on original chain n sprockets, with the rubber on the front

[wicklamulla]

Dave is it pissible to unclip or remove that red rubber damping ring as i was wondering if it looks identical to my MKIIa sprocket with the holes thru it ??

[aircooled68]

<!--quoteo(post=89231:date=Sat 28th Jun 2008, 10:26 PM:name=wicklamulla)-->QUOTE(wicklamulla @ Sat 28th Jun 2008, 10:26 PM) <{POST_SNAPBACK}><!--quotec-->Dave is it pissible to unclip or remove that red rubber damping ring as i was wondering if it looks identical to my MKIIa sprocket with the holes thru it ??<!--QuoteEnd--><!--QuoteEEnd-->


Will have a look as soon as...



Dave

[wicklamulla]

some pics and video of wear on the output shaft splines and the JT sprocket splines.













here the video clearly shows how much movement was available with the worn JT sprocket on the output shaft whereas the genuine yam sprocket (the one that looks loike a piece of Emmental cheese) despite being worn is a better fit onto the output shaft. Genuine Yam sprockets for me always.

i'm not sure these 3 vid clips below can be viewed so follow/play around with the links and they might work !!

Video1
Video2
Video3

This post was last modified: 29-06-2008, 08:43 AM by dapleb.

[robelst]

Hmm, curious.
When I replaced the well-worn JT sprocket on my used MK2A at 35k there was no noticeable wear on the splines or the "inner" teeth of the sprocket. I replaced it with another JT "high carbon", checked it a while ago when it was 20k old and same story again. The bike is now 60k old (100,000 km, ta-daah!) and all seems perfectly fine on non-original sprockets.

I suppose if the nut or thread is bad the sprocket can start moving and cause wear; or would it be the other way round? Or would there be different JT sprockets available with a different thickness? [img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]

[wicklamulla]

Robelst have u a pic of the JT sporx you use please ? we cud compare it to the one above in my pics.

[TonyDevil]

i covered not only the valleys between the sprocket,washer&nut in 638 but also the splines and thread on the output shaft
wonder if its gonna come off? [img]style_emoticons/<#EMO_DIR#>/doubtfull.gif[/img]

[wicklamulla]

<!--quoteo(post=89270:date=Sun 29th Jun 2008, 02:52 PM:name=TonyDevil)-->QUOTE(TonyDevil @ Sun 29th Jun 2008, 02:52 PM) <{POST_SNAPBACK}><!--quotec-->i covered not only the valleys between the sprocket,washer&nut in 638 but also the splines and thread on the output shaft
wonder if its gonna come off? [img]style_emoticons/<#EMO_DIR#>/doubtfull.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->
has it done alorra miles since ya 'glued' it on Tone ? sounds loike it cud be a reet pig to remove, cud ya heat it up with a hot air paint stripper to soften the Loctite a bit ?

[TonyDevil]

<!--quoteo(post=89273:date=Sun 29th Jun 2008, 02:58 PM:name=wicklamulla)-->QUOTE(wicklamulla @ Sun 29th Jun 2008, 02:58 PM) <{POST_SNAPBACK}><!--quotec-->has it done alorra miles since ya 'glued' it on Tone ? sounds loike it cud be a reet pig to remove, cud ya heat it up with a hot air paint stripper to soften the Loctite a bit ?<!--QuoteEnd--><!--QuoteEEnd-->
12,000miles ish
the chain had its 2nd tightening last week so reckon another 5000 before it needs changing
however i'm hopefully fitting a new engine on thursday so shall need to remove it then.....

[Guest]

<!--quoteo(post=89273:date=Sun 29th Jun 2008, 02:58 PM:name=wicklamulla)-->QUOTE(wicklamulla @ Sun 29th Jun 2008, 02:58 PM) <{POST_SNAPBACK}><!--quotec-->has it done alorra miles since ya 'glued' it on Tone ? sounds loike it cud be a reet pig to remove, cud ya heat it up with a hot air paint stripper to soften the Loctite a bit ?<!--QuoteEnd--><!--QuoteEEnd-->

Yes, heating the sprocket will soften the loctite (as it is basically just a thermoplastic), but you may damage the output shaft seal, with the heat required.

<!--quoteo(post=89217:date=Sat 28th Jun 2008, 09:26 PM:name=dapleb)-->QUOTE(dapleb @ Sat 28th Jun 2008, 09:26 PM) <{POST_SNAPBACK}><!--quotec-->but don't understand how for some the nut seems to have moved on the threads, or is that not the case?<!--QuoteEnd--><!--QuoteEEnd-->

Because it is such a fine pitch, I believe it is prob due sideways movement when the nut is effectively loose, causing it to cross thread / jump threads.
A properly torqued nut will never jump a thread - I can guarantee that if it has, then it was loose to begin with

<!--quoteo(post=89217:date=Sat 28th Jun 2008, 09:26 PM:name=dapleb)-->QUOTE(dapleb @ Sat 28th Jun 2008, 09:26 PM) <{POST_SNAPBACK}><!--quotec-->Need to go and re-read your theory about all this GG<!--QuoteEnd--><!--QuoteEEnd-->

full explanation here

<!--quoteo(post=89270:date=Sun 29th Jun 2008, 02:52 PM:name=TonyDevil)-->QUOTE(TonyDevil @ Sun 29th Jun 2008, 02:52 PM) <{POST_SNAPBACK}><!--quotec-->i covered not only the valleys between the sprocket,washer&nut in 638 but also the splines and thread on the output shaft
wonder if its gonna come off? [img]style_emoticons/<#EMO_DIR#>/doubtfull.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->

You are about to experience just how good 638 is
All that is needed is a drop in each valley on the shaft and in the sprocket - 638 is designed to wick into the gaps
None will be required on the threads if you have a lock washer


Wick - that JT sprocket is well sloppy. I would suggest if has worn and wasn't like this when new (unless you have a new one that is the same.
I used a JT front for over 30K miles and it never loosened

This post was last modified: 29-06-2008, 04:45 PM by GuyGraham.