Broken Torque Rod Bolt

[LowRyter]

I dropped off the Greenie for a new rear tire, brakes, et al.,  was told the torque rod bolt in the rear suspension was sheared and was holding on by a nub.  I don't know if this is common, perhaps it's worth checking.  I know I never looked at it.

FYI

[docc]

Talking about the frame end? Definitely an issue. When was the last time any of us inspected that? A formula for disaster when neglected.

Kudos to your technician finding that. It should be inspected, cleaned, and greased with waterproof grease at every rear tire change . . .

https://www.v11lemans.com/forums/topic/22039-torque-reaction-rods/

The torque reaction rod bushings , and its pivots, are a line item in the Wheels Off Maintenance Checklist:

 

[kalev11]

Yep that bolt has very a hard job to do. The name torque rod bolt gives a hint as to the stress it endures. 
Mine sheared off as well, and on a very long solo trip crossing 2 mountain ranges. 
Fortunately my Grey Goose had mercy on me and with a little luck I limped home where I could replace that very same bolt. It’s easy and simple to inspect or replace at home but would be a challenge out on the road. 
Im glad you shared this critical issue with the forum. 

[al_roethlisberger]

What's the size and spec of that bolt in the event someone needs to replace it?

Perhaps falling into the "if it ain't broke don't fix it" category, but I wonder if that bolt should possibly be replaced after X miles or years as maintenance?

[docc]

23 hours ago, al_roethlisberger said:

What's the size and spec of that bolt in the event someone needs to replace it?

Perhaps falling into the "if it ain't broke don't fix it" category, but I wonder if that bolt should possibly be replaced after X miles or years as maintenance?

Parts Catalog for GU37357706 ("1st Series") states M10 x 59 (mm long), yet sourcing one with that much shaft area may not be as simple as a stop by the hardware store . . .

[al_roethlisberger]

[docc]

I can get close with Mcmaster-Carr, but the minimum thread length looks like "26mm" and our application appears to be less than 20 of threads. So, the linked 60mm would not have enough clear shaft area.

Perhaps buying the bolt longer and trimming it to length leaving the correct amount of the bolt shaft unthreaded . . .

[LowRyter]

Then I'm not alone here.  My bike has 50k miles if that's any guide.  Hopefully I've got a stronger bolt.

In other news the tech dropped the bike,,,,broke the rt side mirror and brake lever. Scratched the valve cover crash guard.  The new brake lever is a different color, another issue............Turning into a project .....not done the dyno tune yet.

[p6x]

https://www.pieces-motoguzzi.com/moto-guzzi-motos/1100-MOTO-GUZZI-MOTORCYCLES/V11/2004/V-11-Le-Mans/Chassis/Transmission-cpl-I/422/48/332000152/999

 

[kalev11]

I often go to an Ace hardware in Richmond. The owner is very proud of his hardware selection. He claims it’s the largest selection east of the Mississippi or something like that. 
It truly is an amazing selection of fasteners and things. 
I chose a M10 shoulder bolt with the appropriate amount of shoulder and cut the threaded section to length as needed. Metric bolts do come in a range of hardnesses similar to Grade 3,5,8, FYI.  It seems Ace Hardware is making a strong comeback and I’m thrilled to see it happening. 

[audiomick]

7 hours ago, kalev11 said:

... Metric bolts do come in a range of hardnesses similar to Grade 3,5,8, FYI. ...

Yes. Here is an explanation of the numbers, translated from here:

 

https://www.rosentaler-schrauben.de/magazin/schrauben-festigkeitsklassen/

Quote

The digit before the decimal point gives information about the tensile strength. It corresponds to 1/100 tensile strength in N/mm². So you can pull on a screw with the designation 8.8 with 800 N/mm² before it breaks. The number after the decimal point gives information about the yield strength. It indicates the force needed to permanently deform the screw by pulling.

For anyone wanting to translate more of the document, I recommend this translator:

https://www.deepl.com/translator

 

Copy the text out of the linked article a paragraph or so at a time, and paste it into the left-hand window on the translator site.

[docc]

11 hours ago, p6x said:

https://www.pieces-motoguzzi.com/moto-guzzi-motos/1100-MOTO-GUZZI-MOTORCYCLES/V11/2004/V-11-Le-Mans/Chassis/Transmission-cpl-I/422/48/332000152/999

 

According to this French site posted by @p6x, the part looks available, but the part number is different than from my 1999-2001 catalog (GU37357706):

https://www.pieces-motoguzzi.com/guzzi-laverda-scarabeo/affectation_pieces_detachees/GU01357731

While MGCycle doesn't bring this number up (nor the number I posted), Harpermoto does show the -7731 part at $1.20US. This does NOT mean they have it! A call to Curtis is the only way to know:

https://www.harpermoto.com/screw-10mmx59mm-01357731.html

@LowRyter and @kalev11, where did your bolts break: at the head or at the base of the threads?

[audiomick]

12 minutes ago, docc said:

... but the part number is different than from what my 1999-2001 catalog:

Interesting...

I just had a look at Wendel Motorraeder in Berlin.

https://wendelmotorraeder.de/moto-guzzi-ersatzteile-und-zubehoer-fuer-v11-modelle-c-30_3006_300602.html

Going by the parts lists there, it looks like the bolt was changed for the models from 2003 onwards.

 

Looking at the Guzzi part numbers listed there ( GU xxxx )

These two actually show two different versions for the bolt

https://wendelmotorraeder.de/kardanwelle-v11-sportmandello-99-01-ex-30_3006_300602_30060201_3006020110_300602011009.html

https://wendelmotorraeder.de/kardanwelle-v11-02-le-mansskura-ex-30_3006_300602_30060203_3006020310_300602031010.html

this one only the "2nd version"

https://wendelmotorraeder.de/kardanwelle-v11-nakedle-manns-01-02-ex-30_3006_300602_30060202_3006020210_300602021010.html

and these two the part number shown in the links in docc's post

https://wendelmotorraeder.de/kardanwelle-v11-03-04-corsa-ex-30_3006_300602_30060204_3006020410_300602041010.html

https://wendelmotorraeder.de/kardanwelle-v11-03-05-cafballabio-ex-30_3006_300602_30060205_3006020510_300602051010.html

 

In the second link, V11 Le Mans / Scura '02, there is a note next to the "first version", the bolt is number 12 in the diagramm (the note "1st version" and "2nd version" is only in the diagramm behind the first link....)

Quote

Version: Bis Rahmen Nr. KT 111393 [M1]

i.e. " up until frame number KT 111393 [M1]

 

BUT!!

the original bolt for the "first" and "second" versions are listed as being unavailable (number crossed out), and an alternative number is listed.

This number also appears in the diagramms for the models after 2003, i.e. the last two links, although the Guzzi part number there is not crossed out. That number links to here:

1035121

 

Without knowing for sure, I would take that to mean that the bolt for the later models will also work in the earlier ones.

[docc]

My early bolt has a smooth head, no markings, indicating mild steel/unhardened.

Do the later bolt heads (2003-onward) reveal a hardening level (i.e.: 10.9 or 12.9)?

Knowing of these failures, it seems prudent to go with a hardened fastener in this location (as well as seeing to the maintenance). I wonder if Moto Guzzi superseded the part thusly . . .

[LowRyter]

11 hours ago, kalev11 said:

I often go to an Ace hardware in Richmond. The owner is very proud of his hardware selection. He claims it’s the largest selection east of the Mississippi or something like that. 
It truly is an amazing selection of fasteners and things. 
I chose a M10 shoulder bolt with the appropriate amount of shoulder and cut the threaded section to length as needed. Metric bolts do come in a range of hardnesses similar to Grade 3,5,8, FYI.  It seems Ace Hardware is making a strong comeback and I’m thrilled to see it happening. 

I go to Ace most of the time.  Seems to be better than Fastenall.  We have industrial fastener supply on the southside of the City in a little town with all the strip clubs.  Minimum purchase is like $20 there. 

Anyway, I played all those hardness grades with a non load bearing bolt assembling my Duc's pannier bracket that sheared.  The new (stronger) one sheared just as the other one.  According to the forum, the better fix was to tap it out and go to a larger size.  Anyway, I'll see if the works.  I'm planning to ride the Duc to MotoGP Austin.  Full confession, I did have my bags overloaded according to Ducati.  It's actually a Givi designed system with a Ducati badge.