BARF - Bay Area Riders Forum

Go Back   BARF - Bay Area Riders Forum > Moto > The Garage


Notices

Reply
 
Thread Tools Display Modes
Old 05-18-2018, 03:36 PM   #1
johnkol
Veteran
 
johnkol's Avatar
 

Join Date: Feb 2008
Location: Union City
Motorcycles: Bultaco
Name: John
Countershaft threads stripped

I went to replace the CS sprocket on my WR250R, and the nut would not turn. Using a breaker bar I was able to turn it, but then realised it was not unthreading.

It appears that the threads have stripped (aftermarket sprocket installed by previous owner), so what are my options now?

1. Dremel the nut out at the flat cut-outs of the CS, then use a thread file to fix the threads (or may have to use a die to re-thread).
2. Take it to a machine shop where other options may be available?
3. Any other ideas?

Here's what it looks like:

johnkol is offline   Reply With Quote
Old 05-18-2018, 04:26 PM   #2
augustiron
2fast 2live 2young 2die
 
augustiron's Avatar
 

Join Date: Mar 2003
Location: Truckee SF Reno
Motorcycles: All of them eventually.
Name: nope
Are you sure you are not turning the CS?
I usually leave the chain on and use the rear brake to hold it while I unscrew the nut.
Are you sure of LH or RH threads?

If ok on both points, ok to carefully grind the nut then punch it off. If you are lucky, just the nut threads failed. If the CS is stripped. Well, pull out your wallet.
__________________
"If you think you can overcome a lack of skill by doubling your efforts, there is no limit to what you cannot accomplish"
augustiron is offline   Reply With Quote
Old 05-18-2018, 04:46 PM   #3
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
its not uncommon on the internet to find ppl that have welded the nut on because they don't want to split the cases and replace the countershaft.

nut still looks peened somewhat. I wouldn't be surprised if you were just turning the engine and/or slipping the clutch.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 05-18-2018, 05:12 PM   #4
thedub
Octane Socks
 
thedub's Avatar
 
AMA #: 2952025

Join Date: Sep 2010
Location: Gardnerville, NV
Motorcycles: R6, Tiger 800, KTM 500, KTM 350
Name: Wiles
What method are you using to hold the countershaft still while you turn the nut without the chain on?
__________________
AFM #77, D36 #166N
Thanks for the support;
Sidi|Motion Pro|C@TT|Vortex|Shoei
thedub is offline   Reply With Quote
Old 05-18-2018, 06:55 PM   #5
Rumbo Sur
learning everyday
 
Rumbo Sur's Avatar
 
1% Contributor

Join Date: Jul 2009
Location: San Rafael, CA
Motorcycles: DR650, Ducati HyperStrada, .
Name: Patrick
My first thought was that it's a left hand thread??? ... and you tried to loosen it going wrong direction? Possible?

Hopefully a machinist can use a die tool to clean up the threads on the shaft and re-use it.

Hope it can be saved, good luck!

If it's frozen, next time try a 50 50 mix of Acetone and ATF. Does a good job freeing up frozen/corroded/rusted fasteners. Soak over night. Way better than
Liquid Wrench and many others.

Last edited by Rumbo Sur; 05-18-2018 at 06:58 PM..
Rumbo Sur is offline   Reply With Quote
Old 05-18-2018, 09:05 PM   #6
johnkol
Veteran
 
johnkol's Avatar
 

Join Date: Feb 2008
Location: Union City
Motorcycles: Bultaco
Name: John
Quote:
Originally Posted by thedub View Post
What method are you using to hold the countershaft still while you turn the nut without the chain on?
Quote:
Originally Posted by augustiron View Post
I usually leave the chain on and use the rear brake to hold it while I unscrew the nut.
Are you sure of LH or RH threads?
That's exactly what I did; with chain on, I stomped on the rear brake and tried to unthread the nut. After encountering so much resistance, I tried RH, but there was no difference; that was when I knew the threads were stripped.

I removed the chain in anticipation of using this sprocket tool that I have on order.

Quote:
Originally Posted by stangmx13 View Post
nut still looks peened somewhat. I wouldn't be surprised if you were just turning the engine and/or slipping the clutch.
I completely removed the peening before attempting to turn the nut; the flange was still mangled in a couple of places, but it is relatively soft metal, so I do not expect it to provide much resistance.

This picture shows the state of the flange a little better:


Quote:
Originally Posted by augustiron View Post
If ok on both points, ok to carefully grind the nut then punch it off. If you are lucky, just the nut threads failed. If the CS is stripped. Well, pull out your wallet.
You mean split the cases to replace CS? I was hoping that a machinist would be able to add some material (even JB Weld), and re-thread with a die. There are no significant lateral forces on this nut, so this should be sufficient for keeping the sprocket in its place.
johnkol is offline   Reply With Quote
Old 05-19-2018, 03:57 AM   #7
Tri750
Mr. Knew it All
 
Tri750's Avatar
 
Contributor

Join Date: Mar 2005
Location: Clovis, CA
Motorcycles: Current: '71 BMW R75 Racer, '73 Z1 Racer, '76 BMW R75/6, '76 Tri 750, '99 BMW R1100RT '07 Kymco 150S
Name: Big Al
I would take a Dremel with a cutoff wheel and cut the nut off at the slot at 12:00 o' clock .
Once it's off, assess.
Order or buy a few nuts now.
If it has to go to a shop, choose one familiar with motorcycles.
When fixed, replace the seal, o-ring if one present.
And keep the extra nuts in your tool box.
If they are the "pinched" or dimpled nuts, they are intended to be used once.
Tri750 is offline   Reply With Quote
Old 05-19-2018, 06:09 AM   #8
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ +++++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Mikezebub
Use impact wrench next time
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.
afm199 is offline   Reply With Quote
Old 05-19-2018, 07:16 AM   #9
Enchanter
Ghost in The Machine
 
Enchanter's Avatar
 
AMA #: 2815246
BARF Admin
Founding Member
Barfie Winner 2007, 2010, 2014, 2017
Contributor ++++++++++

Join Date: Apr 2002
Location: SF Bay Area
Motorcycles: Attack™-ed R1 & hybrid S1000rr
Name:
I don't see evidence of the nut or shaft (gigiddy) stripping. As was pointed out previously, I too suspect that the output shaft was turning. Put the chain back on and put a 2x4 between the spokes of the wheel and resting on the swingarm. Try again.
__________________
A superior rider uses superior judgment to avoid situations that require superior skill.

Quote:
Originally Posted by DataDan View Post
Be resilient. After an unpleasant surprise or close call, get your head back in the game quickly. Learn whatever lesson you can and move on.
Quote:
Originally Posted by cardinal03 View Post
The panties. Unbunch them.
Occam's Razor: The simplest explanation tends to be the right one.
Hanlon's Razor: Never attribute to malice that which is adequately explained by stupidity.


BARF Terms of Service
Enchanter is offline   Reply With Quote
Old 05-19-2018, 07:23 AM   #10
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ +++++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Mikezebub
Quote:
Originally Posted by Enchanter View Post
I don't see evidence of the nut or shaft (gigiddy) stripping. As was pointed out previously, I too suspect that the output shaft was turning. Put the chain back on and put a 2x4 between the spokes of the wheel and resting on the swingarm. Try again.
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.
afm199 is offline   Reply With Quote
Old 05-19-2018, 08:29 AM   #11
auntiebling
megalomaniacal troglodyte
 
auntiebling's Avatar
 
BARF Moderator (ooh, fancy!)
Barfie Winner 2017
Contributor

Join Date: Apr 2004
Location: atop the parapet
Motorcycles: .
Name:
i'll +1 for trying again. instead of relying on the brake and your coordination (kinda hard to mash the brake while simultaneously reefing on the breaker bar and apply 100% effort to both) put something in the rear wheel to jam it against the swingarm. think 2x4, but that'll probably be too big. ratchet straps or rope would likely work as well once you get all the slack out.

the threads adjacent to the slot in the countershaft don't look buggered, or covered in shavings, which would likely be the case if the nut stripped.

putting a little heat on the nut, as accurately as possible so countershaft stays as cold as possible, would also help. a small butane torch would work well, something like this
https://www.amazon.com/GiBot-Culinar...s=butane+torch

if you have a propane plumbers torch it'll probably heat everything up which isn't all that helpful and could damage seals. hot to the touch is all you need. not red or anywhere near it.
__________________
no shirt, no shoes: No dice BARF TOS
every book is a children's book if the kid can read
-mitchbarf memes
my dad is an engineer
17/38 sprockets
CARB bikes list CA DMV fee calculators

Classifieds Forum Rules
Quote:
Originally Posted by Abacinator View Post
Love that subway tile backsplash, auntie
auntiebling is offline   Reply With Quote
Old 05-19-2018, 08:44 AM   #12
mototireguy
Moto Tire Veteran
 
mototireguy's Avatar
 
Valgar beer donor
Contributor +

Join Date: Mar 2004
Location: San Francisco, CA
Motorcycles: FJR13 - XR650L - Madass 125
Name: Robbie
Impact gun might be the magic sauce.
__________________
* Motorcycle Tire Services @ http://MotoTireGuy.com
* 1064 Revere Ave, San Francisco CA 94124
mototireguy is offline   Reply With Quote
Old 05-19-2018, 11:29 AM   #13
ST Guy
Veteran
 
ST Guy's Avatar
 

Join Date: Nov 2006
Location: South Bay
Motorcycles: Honda ST1100 ABS (tweaked here and there)
Name:
But BEFORE cranking on it any more, know for sure which way to turn it. 'Hard to say from the pix, but it looks like a right hand thread so turn it counterclockwise.

And heat up the nut some before cranking on it. Do NOT get it red hot!
__________________
It's not the answer that enlightens, but the question. - Eugene Ionesco

Let us not pray to be sheltered from dangers but to be fearless when facing them. - Rabindranath Tagore

A mind all logic is like a knife all blade. It makes the hand bleed that uses it. - Rabindranath Tagore
ST Guy is offline   Reply With Quote
Old 05-19-2018, 02:25 PM   #14
johnkol
Veteran
 
johnkol's Avatar
 

Join Date: Feb 2008
Location: Union City
Motorcycles: Bultaco
Name: John
Quote:
Originally Posted by Enchanter View Post
I don't see evidence of the nut or shaft (gigiddy) stripping. As was pointed out previously, I too suspect that the output shaft was turning.
You guys were right: the countershaft was turning, which means that there was nothing wrong with the threads, but that means something worse -- there is something wrong with the CS splines:



and the corresponding sprocket splines:



How on earth was the bike working without a problem? And why was the spline shearing split between the CS splines and the sprocket splines?

And the bigger question, what do I do next? I put on a new sprocket, and it engages the CS splines that are still in good condition, but how long will these last?

Any idea how much it would be for a shop to split the cases in order to replace the countershaft?
johnkol is offline   Reply With Quote
Old 05-19-2018, 03:00 PM   #15
buellistic
Veteran
 
buellistic's Avatar
 
Contributor

Join Date: Nov 2006
Location: Here
Motorcycles: kool loud one + 11 more
Name:
Maybe a spacer issue or the wrong sprocket..
File it clean and check it with the right sprocket And spacer..

Last edited by buellistic; 05-19-2018 at 03:01 PM..
buellistic is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 02:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.