Stripped sprocket carrier

[vagrant318]

So I was changing chain and sprockets and while torquing the rear sprocket stripped 2 of the studs on what yamaha calls the clutch hub. Reading about it sounds like it's a thing with the fz09 and fz/mt07 as well. I'm going to try and get it fixed through my extended warranty but otherwise will have to fiX or take to the shop.  One bolt is still stuck on and just spinning.. whats my best option for removing this and the other damaged stud besides taking to the shop?

[Samm]

3 hours ago, vagrant318 said:

So I was changing chain and sprockets and while torquing the rear sprocket stripped 2 of the studs on what yamaha calls the clutch hub. Reading about it sounds like it's a thing with the fz09 and fz/mt07 as well. I'm going to try and get it fixed through my extended warranty but otherwise will have to fiX or take to the shop.  One bolt is still stuck on and just spinning.. whats my best option for removing this and the other damaged stud besides taking to the shop?

I had this issue too a while back. Didn’t manage to break free any of the studs so I just chased the threads with a die and used new nuts. If you’ve got a stud that’s spinning you’ll probably have to cut/grind it off and maybe replace with a new stud with a little JB Weld if the stud hole is chewed out. Alternatively replace it with a normal bolt and nut if you’ve got enough clearance. 

[Dougie]

If the stud is spinning then you might get it free turning it and pulling/pushing at the same time. Easier said than done. Do the holes already have wire thread inserts in or threads cut directly into the carrier? If the carrier threads are ok ( just studs damaged) then clear it out and use loctite 638 to reseat new ones. If not, a new wire thread insert or timesert will do the job. I’m a fan of timeserts personally, but a wire insert is fine in this sort of scenario as it doesn’t need to be oil tight. 

[vagrant318]

4 hours ago, Samm said:

I had this issue too a while back. Didn’t manage to break free any of the studs so I just chased the threads with a die and used new nuts. If you’ve got a stud that’s spinning you’ll probably have to cut/grind it off and maybe replace with a new stud with a little JB Weld if the stud hole is chewed out. Alternatively replace it with a normal bolt and nut if you’ve got enough clearance. 

It appears the nut is spinning and the stud hasn't moved. I'd be a bit sketched out to leave that nut on there and just clean up the other one but I guess that's an option 

[vagrant318]

3 hours ago, Dougie said:

If the stud is spinning then you might get it free turning it and pulling/pushing at the same time. Easier said than done. Do the holes already have wire thread inserts in or threads cut directly into the carrier? If the carrier threads are ok ( just studs damaged) then clear it out and use loctite 638 to reseat new ones. If not, a new wire thread insert or timesert will do the job. I’m a fan of timeserts personally, but a wire insert is fine in this sort of scenario as it doesn’t need to be oil tight. 

The stud isn't spinning and I really don't know how they're placed into the carrier. Using nuts and bolts in this application would have been much simpler 

[vagrant318]

I got the stripped studs out. Can anyone think of any major reasons not to use bolts at least temporarily? They would be across from each other balanced and probably weigh similar to the stud and nut

Edited June 7 by vagrant318

[Dougie]

Well done bud. I think you’ll be ok for a good temp fix but I’d order the studs now and put it back to standard. Even if just for the simplicity of the nuts going on and off the studs, not bolts going in and out of the carrier maybe wearing it if it’s the weak link. I’d only use a weak thread lock for the bolts and use stud lock or bearing fit when you put the studs back in. 

[Samm]

Problem solved, that’ll last forever.

[vagrant318]

Can anyone confirm- are the factory sprocket nuts single use or can I reuse them? The ones I got from sprocket center are too tall and don't engage the nyloc

I certainly don't want to strip another stud. 

Edited June 8 by vagrant318

[Samm]

Should be able to reuse no problem just don’t use the torque spec in the book or you risk stripping. Just go by feel.

[vagrant318]

On 6/6/2023 at 11:57 PM, Dougie said:

Well done bud. I think you’ll be ok for a good temp fix but I’d order the studs now and put it back to standard. Even if just for the simplicity of the nuts going on and off the studs, not bolts going in and out of the carrier maybe wearing it if it’s the weak link. I’d only use a weak thread lock for the bolts and use stud lock or bearing fit when you put the studs back in. 

Studs ordered.. will probably change back to studs at next sprocket change unless the bolts come loose.. then I cracked my rivet style master link. This simple job became a real headache lol

[Samm]

16 hours ago, Samm said:

Should be able to reuse no problem just don’t use the torque spec in the book or you risk stripping. Just go by feel.

I should say that as long as the nuts didn’t give you any trouble coming off/going on they are fine to reuse. The nuts from your stripped studs should be thrown out unless you can chase them with a tap and still have ample threads left for a good hold 

[headwinded]

@vagrant318  .... Curious as to how you got the stripped stud out?   I ran into this problem this evening, and probably just want to replace them all to be safe.   20 bucks each for these trash studs sure is excessive, lol.

 

As for the 'why not bolts thing, it's probably to ensure that any damage doesn't strip the carrier itself, which is a way more expensive part to deal with.

Edited November 23 by headwinded

[vagrant318]

2 hours ago, headwinded said:

@vagrant318  .... Curious as to how you got the stripped stud out?   I ran into this problem this evening, and probably just want to replace them all to be safe.   20 bucks each for these trash studs sure is excessive, lol.

 

As for the 'why not bolts thing, it's probably to ensure that any damage doesn't strip the carrier itself, which is a way more expensive part to deal with.

I ended up taking it to the shop If I remember correctly but could probably back the stripped studs out with a vice grips. My assumption was the carrier threads were stripped fortunately only the studs. The bolts are still in my carrier actually, have been since the beginning of the summer. I also picked up a spare sprocket carrier cheap off ebay just in case...

[roygilbo]

On 6/6/2023 at 3:31 AM, Samm said:

I had this issue too a while back. Didn’t manage to break free any of the studs so I just chased the threads with a die and used new nuts. If you’ve got a stud that’s spinning you’ll probably have to cut/grind it off and maybe replace with a new stud with a little JB Weld if the stud hole is chewed out. Alternatively replace it with a normal bolt and nut if you’ve got enough clearance. 

Is this a common problem when replacing the rear sprocket?  Was it from over torquing? Is there any way to prevent this if it is not a torque thing? 

[vagrant318]

26 minutes ago, roygilbo said:

Is this a common problem when replacing the rear sprocket?  Was it from over torquing? Is there any way to prevent this if it is not a torque thing? 

The manual says I believe 55 ft lbs ? Don't torque with a 1/2" torque wrench.  Use a 3/8 and increase gradually to err on side of caution.  Pretty sure the youtube video I watched dude was using a 1/2 " and set it and go no problem.. so I didn't think there would be any issue 

[Samm]

Mine was the result of using the specified torque on studs that probably had excessive lube on them from removal. My screw up. On my last sprocket change I just tightened with a ratchet to what felt right and used medium strength (blue) locktite.

[headwinded]

10 hours ago, roygilbo said:

Is this a common problem when replacing the rear sprocket?  Was it from over torquing? Is there any way to prevent this if it is not a torque thing? 

 

Service manual says 59lb ft for these bolts which seems quite high honestly.

[roygilbo]

1 hour ago, Samm said:

Mine was the result of using the specified torque on studs that probably had excessive lube on them from removal. My screw up. On my last sprocket change I just tightened with a ratchet to what felt right and used medium strength (blue) locktite.

So I have it correct, the problem arose when replacing the sprocket and torquing rather than taking of the nuts originally? 

[Samm]

13 minutes ago, roygilbo said:

So I have it correct, the problem arose when replacing the sprocket and torquing rather than taking of the nuts originally? 

Yes. Removal went smooth. Over torqued when reinstalling. 

[JB700]

2 hours ago, Samm said:

Yes. Removal went smooth. Over torqued when reinstalling. 

Why is there so much attention paid to tightening torque values on your side of the Atlantic ?

Some items are torque critical but many aren’t and often the values from Yamaha are often not that reliable 

[Samm]

2 minutes ago, JB700 said:

Why is there so much attention paid to tightening torque values on your side of the Atlantic ?

Some items are torque critical but many aren’t and often the values from Yamaha are often not that reliable 

You’re right. Live and learn. 

[Redneckj]

What do the rear sprocket bolts and the oil drain plug have in common in the T7 owners manual?

 

[vagrant318]

3 hours ago, JB700 said:

Why is there so much attention paid to tightening torque values on your side of the Atlantic ?

Some items are torque critical but many aren’t and often the values from Yamaha are often not that reliable 

If you want to maintain your machines properly then it makes sense to follow proper maintenance procedures including torquing of fasteners to correct specs put out by the company who designed it. That being said some of yamahas values seem way too high.

[JB700]

1 hour ago, vagrant318 said:

If you want to maintain your machines properly then it makes sense to follow proper maintenance procedures including torquing of fasteners to correct specs put out by the company who designed it. That being said some of yamahas values seem way too high.

What’s wrong with old fashioned common sense 

I rarely use a torque wrench and rely on old fashioned feel 

[vagrant318]

45 minutes ago, JB700 said:

What’s wrong with old fashioned common sense 

I rarely use a torque wrench and rely on old fashioned feel 

If that works for you then nothing. I did that for quite a while but have experienced issues from spark plugs backing out or other issues.  I'm also a scientist and when I have access to owners manual and a torque wrench I'll do something by the book. Obviously that doesn't always work out right anyway lol