161 replies to this topic

[robelst]

The constant back and forth shocks as lemonentrails quite rightly points out from the acceleration and deceleration, makes the sprocket rock back and forth.

I suppose the free-play on the drive-train of early TDMs the size of Norway will give some additional hammering as well

[dapleb]

I suppose the free-play on the drive-train of early TDMs the size of Norway will give some additional hammering as well

yup......mine is like a sloide'ammer for sure.

[slartybartfarst]

dont buy all yammie, not needed
i also wouldnt spend the extra on x-ring, o-ring is more than enough

Ordered the Yam kit in the end - £139 , they wanted £30 for the front sproket of 9'r. Seemed simplest route as the quality is good and getting it won't involve any costly postage or missing the courier/postman shinanigins. I also ordered the nut and washer just to be on the safe side.

I also ordered the two rear bungee hook brackets. (These are swapped when you fit a Givi Monorack and I want to sell the rack complete). One side is £7.50 and the other £6.50 go figure.

Slarty

[lemonentrails]

Not all other bike have this set up But their sprockets nuts and tab whashers still come loose
[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' Yes they do
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. the output shaft on their bikes were trashed because they ran too long with loose sprockets

Could you explain to me then how the small gap appears twixt sprocket and oil seal collar when said collar (and bearing) is an extreeeemly tight fit needing 10's of tons of hydraulic pressure to move as someone in this very thread or one similar had to apply to remove the bearing and collar?
Also said collar would have to move inwards towards gearbox internals to allow a gap to appear before the sprocket can become loose and rock, this is, if we assume the situation is as you describe it and the nut does not loosen itself?
Which large force would it be and where does it come from to move said collar/bearing.

Once the sprocket has come loose and started to fret the spline so it is no longer a snug fit, no matter how tight the nut it will always be a weak point and be prone to coming loose and rocking back and forth again.So using loctite on the splines in this situation is a good idea.

By the way I read this thread from beggining to end severel times, every time it came up and I am in full understanding of what you are saying ,I dont doubt the situation with drz is anything other than how you say it is. But this is a tdm we are talking about however similar the gearbox setup.
Lem

[wicklamulla]

tink oil opt ferra boike with shaft droive nex toime huh

[dapleb]

2000+ (ish) miles later and the sprocket is solid. So its either: New nut, New washer, loctite 638 on the spline/sprocket interface, normal locite on the shaft thread that has prevented me gettin any output shaft issues.

[David H]

Sounds the same as mine was. 14k miles.
I replaced with a genuwine yammy kit.

[wicklamulla]

tanks Guy, that confirms it fer me then folks as oil be loctiting me nuts in place from now on.

[lemonentrails]

loctiting the nut won't help - the nut don't move as its held in place by the tab washer

Loctite on the SPLINES is what is required

Guy ,Just out of interest did u replace tab washer with new and if so what was the condition of the splines on the old one?
Lem

[dapleb]

Guy ,Just out of interest did u replace tab washer with new and if so what was the condition of the splines on the old one?
Lem

Replaced moine Lementity, and splines were snot noticeably worn.

[lemonentrails]

Replaced moine Lementity, and splines were snot noticeably worn.

fairy snuff

[Guinness]

-//-
Loctite them sprockets on boys and girls

i wish someone had told me that a few years ago, ild still be on my '92 MK1
AND WOULDNT HAVE BROKEN DOWN IN IRELAND ON THE WAY BACK TO THE FERRY ...

[lemonentrails]

Used the same tab washer, as it was mint
Splined section of the tab washer was like new

Jolly good, It had'nt slackened compleately and you caught it before any damage was caused !
So you dont advise loctite on the nut too,like wot I would ?

[lemonentrails]

Not required on the nut, as the nut don't move, and is held in place by the tab washer
By all means put plenty on the nut but it won't stop this problem

True, and Not once the sprocket has been allowed to rock n roll!which is the reason to loctite the nut in the first place the tab washer does allow slight movement once the rocking movement of the sprocket is transfered through washer to nut! yes indeedy seen it so many times. loctite wil stop this .

Its the back and forth rocking of the sprocket on the splines that needs to be eliminated, which the Loctite 638 does by forming a thermoset plastic in the gaps between shaft and sprocket and hence stop movement

Erm this is what i have been saying ,Stop the baggy nuts in the first instance and you stop the sprox rocking forces.

638 is robust enough not to get destroyed by the forces of acceleration and deceleration, where as the stuff you buy in Halfords etc is just crap (Loctite Stud 'n' Bearing for instance) and will get destroyed by the forces involved

The stud n bearing fit is adequate for its intended porpoise!

People of the world lock up your nuts!
Bye bye

Edited by lemonentrails, 29 July 2008 - 09:15 am.