had a loose c/s sprocket nut - did loctite fix and now a problem shifting from n - 1st

[PattyMil]

G'day from Australia mates ?

i will try to keep this short and to the point.

last week my c/s sprocket nut came loose on the motorway doing 120kph

the bike dumped the oil out of the seal and it went everywhere.... i rode on for about 5 minutes before i was aware what has happening and then exited the motorway and shut her down.

i drained 1 litre from the bike, so i lost half of the oil.

i installed a new seal and metal spacer. Bearing felt fine - no binding etc.

 

I have ridden it 15km home but there is a problem that wasnt there before the sprocket incident,

what happens is that, when i stop and go into neutral, the bike is very very hard to get back into 1st gear. rocking the bike forward and back does nothing to help. I have never had this problem before and im wondering what could be the cause.. 

clutch cable and shifter were not touched at all so i assume they are within adjustment.

i was wondering if running the bike with only 1litre of oil could have damaged the clutch??

i am off to suzuki now to grab a new clutch cable and have a chat to them.

i would take it to them but i like to do everything myself where possible.

i am ready to put in new clutch plates and springs but i would like to get a few opinions on here if i can first.

 

sorry this was longer than i intended ?

cheers 

Patty

 

 

[ohgood]

an overfilled crankcase can make shifting into 1st gear more difficult. 

 

an improperly adjusted clutch cable can also make it more difficult. 

 

i doubt you need new clutch discs unless it's slipping. 

[Noble]

If it is in 1st gear, motor running, with the clutch lever pulled all the way in, goes the bike want to creep forward?

 

Did you test for free rotation of the countershaft sprocket in neutral after the nut was tightened?  

 

What torque did you use on the nut?

[PattyMil]

gday fellas, 

thanks for replying ?

to answer your questions:

the bike oil level is within the high and low mark on the dipstick when hot.

the clutch cable seems within adjustment and the problem is still there with lots of freeplay in cable or none at all.

in first gear, clutch in, the bike doesnt seem to want to move forward, i will have to double check this.

 

i have noticed with bike on stand and engine on - the rear tyre moves in neutral ( i know this is normal for all/most bikes) but as i increase the engine speed, the rear wheel speed increases also.... is this normal?????

i was just hoping this is a sticky clutch issue and will come good but after reading some forums im very concerned about my bearing and 2nd gear bushing... i dont want that shit to seize up on me while riding.

 

noble, you have got me worried about the countershaft bearing.

after the loctite fix i torqued the nut down to 105ftlbs and... for me the sprocket feels a little firm to turn by hand. :(

i can turn it with one index finger but it just doesnt feel right..  it seems to be not linear if that makes sense? it is firm to rotate and then easier and then firm as the sprocket goes around 360deg..  I was hoping it was because the seal and spacer are new and were a snug fit, but after reading some other posts on tt, i am worried my bearing or bushing could be bad..

there seems to be zero shaft movement on the countershaft so the bearing hasnt collapsed i think.

i need to add, the sprocket was quite easy to turn before i replaced the seal and spacer... now that i have torqued it up it feels like its binding.

i am going to pull chain and sprocket nut and see if the sprocket is easier to turn.. i guess if this is the case, i will be splitting the case sometime soon. :(

maybe i will just get a &%$#@!en s1000rr... 

 

anyway cheers for looking and trying to help... deadset legends

Patty

[Noble]

Yes, you have the right idea. Loosen the nut and see if the binding goes away.  If so, you have identified the problem as the second gear bushing being warn so there is no end thrust clearance.  Report back. There are of a couple of alternatives to splitting the cases to replace the busing.

[PattyMil]

thanks for getting back to me so fast mr noble...

yes what you said is correct.. i loosened off the sprocket nut and the binding was gone.

so i assume that confirms that i have damaged 2nd gear bushing.  i would be stupid to keep riding it now so, what are my options..?

i am so devastated that this has happened the drz has been really really good to me.. it hurts me to see it now with a terminal problem.

 

once again thanks for your help... without  this forum i would have kept riding the bike and fark.. who knows what would have happened then...

big respect to noble and all the other TT contributors

Patty

[Noble]

OK, options are:

 

1) Tighten the nut only finger tight, bend the lock washer and depend on the lock washer to keep the nut in place.  Inspect fairly often and carry a new nut and lock washer with you.  In time the lock washer will failI so it needs periodic replacement.  I know 1 person this has worked for him for 9 years.

 

2) Custom make a 1mm thick flat washer 18mm ID and OD to fit in the counterbore of the nut (this allows the nut to tighten against the end of the countershaft without running out of threads). Omit the lock washer. Trial assembly - you want the nut to go full tight but not clamp on the sprocket, however you do not want excessive clearance between the nut and sprocket.  This has to be custom fitted for your specific motorcycle and sprocket.  You are looking for about 0.05mm to 0.25mm clearance (.002" to .010").  To increase clearance face off the nut. To decrease clearance deepen the counterbore in the nut.  This allows the sprocket to float with the nut tight and there is no mechanical stress on the nut to loosen it. This approach is working for me for about 3 years now.  I do use Loctite thread locker on the nut. 

 

3) Both of the above approaches fly in the face of accepted practice.  The truly correct way to rectify the problem is of course to split the cases and replace the warn parts.

 

Contrary to some beliefs, 1 and 2 do not cause additional wear or problems in the transmission.  1 and 2 can accelerate wear on the splines that drive the sprocket but it does not seem to be rapid at all.  And if the splines do wear badly, then it is time to repair per 3 above. The primary concern is to keep the countershaft sprocket in place and oil in the motor.  If it falls off and oil is lost, all kinds of bad things can happen.  Oil on the rear tire and seize the motor to name a few.

[jjktmrider]

I put a self locking nut on mine so I can vary how much clearance I have now. Well to a point , it still needs to be touching the shaft end at least.

Edited November 13, 2015 by jjktmrider

[mynameis]

OK, options are:

 

1) Tighten the nut only finger tight, bend the lock washer and depend on the lock washer to keep the nut in place.  Inspect fairly often and carry a new nut and lock washer with you.  In time the lock washer will failI so it needs periodic replacement.  I know 1 person this has worked for him for 9 years.

 

2) Custom make a 1mm thick flat washer 18mm ID and OD to fit in the counterbore of the nut (this allows the nut to tighten against the end of the countershaft without running out of threads). Omit the lock washer. Trial assembly - you want the nut to go full tight but not clamp on the sprocket, however you do not want excessive clearance between the nut and sprocket.  This has to be custom fitted for your specific motorcycle and sprocket.  You are looking for about 0.05mm to 0.25mm clearance (.002" to .010").  To increase clearance face off the nut. To decrease clearance deepen the counterbore in the nut.  This allows the sprocket to float with the nut tight and there is no mechanical stress on the nut to loosen it. This approach is working for me for about 3 years now.  I do use Loctite thread locker on the nut. 

 

3) Both of the above approaches fly in the face of accepted practice.  The truly correct way to rectify the problem is of course to split the cases and replace the warn parts.

 

Contrary to some beliefs, 1 and 2 do not cause additional wear or problems in the transmission.  1 and 2 can accelerate wear on the splines that drive the sprocket but it does not seem to be rapid at all.  And if the splines do wear badly, then it is time to repair per 3 above. The primary concern is to keep the countershaft sprocket in place and oil in the motor.  If it falls off and oil is lost, all kinds of bad things can happen.  Oil on the rear tire and seize the motor to name a few.

Hi threre.Sorry to come across a little thick but can you explain number 2 a little more clearly.Not quite sure whats going on and how its helping.

[OldYelMXer]

Option 2 is to make a washer that will not slide on to the splines but stay on the threads of the counter shaft so that the counter shaft nut will tighten against the washer instead of against the counter shaft sprocket.

= )

[Noble]

Correct.  The approach here is to make the nut a retainer rather than a clamper.  Allowing the sprocket to float relieves any thrust problems in the transmission due the the 2nd gear spacer being warn. Being able to fully tighten the nut without clamping the sprocket assures the nut will stay on.  The tight nut without clamping on the sprocket has no physical action acting on it trying to loosen the nut so it is always going to stay on.  Method 1 and method 2 both do the same thing.  Method 2 is more difficult but more positive.

[mynameis]

I see.thanks for the explanation