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Spring reprise


belfastguzzi
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Guest jerroldt

I was thinking that a roller bushing placed on the boss would ease the friction but it seems that the spring breaks when it wants to with no wear at the pivot. It must be a product of tempering. In the scheme of things the rate of spring breakage is probably small in relation to the number of Guzzi's sold but who wants to wait for the hammer to drop? The Le Mans doesn't seem to be a good candidate for the old external shifter spring fix due to the complexity and inaccessabiliy of the shifting mechanism. My answer is to wait until it happens and then deal with it. If I can get 30K miles without a broken spring I will feel lucky.

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I was thinking that a roller bushing placed on the boss would ease the friction but it seems that the spring breaks when it wants to with no wear at the pivot.

With the correct size of boss and spring coil, there shouldn't be any great amount of friction. The coil should just tighten itself up but not so much that it squeezes on the boss. When the boss is too big, it does squeeze and bind, so stopping movement at the hook-end to boss length of the spring wire. That would happen the same way even with a 'frictionless' boss/bush if its diameter was too big.

 

The wear won't happen at the big boss/pivot but at the spring hook where a very much smaller area of wire is under stress.

 

Has anyone else had a look at the parts (including he shift plate) to see what sort of wear is on them? Mike S and Al R were talking about having a check a while ago. :nerd:

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I have replaced my broken spring now. :D

There my be some truth to the OE spring ID being to small or the Boss that it goes on being to big.I don't have any hard truths here, just observations.

The boss for my spring was 16mm, still is.no filling done. The ID of the coil on the spring that broke was 17-18mm. The ID of the replacement spring (MG) is 20-21mm.

The wire diameter of the broken spring was 1.99mm.The replacement spring wire dia.is 2.15.(MG) I had to file the other end down so that it would ride on the rachet arm pivot correctly.

The shaft that holds the other end had a small groove worn in it by the bent tab of the spring (the part that breaks) I took the trusty dremel tool and smoothed all of that so that there wasn't a groove anymore.The new spring hooks a couple of mm away from where the old one was.

Being as how mine lasted for 26,000miles :blink: , that may be why I had a groove worn on the shift shaft.I don't know if this groove was present on any of the low mileage bikes that have been talked about.

as to a road side repair, well, I don't know about that. Yes, anything is possible, but I was in the shop and it was a major pain in the ass :angry: to get the bottom 3 allen bolts out. And depending on what year bike it is and the type of glue Guido used :huh2: ,the side cover may or may not come off easy.

I think I would be more incilned to just cary a spare spring. If one did break, find the nearest accomodating motorcycle shop and tell them you have the part and the directions for replacement and see if you could help out. I spent about 2 hours on mine but I was taking pictures and measuring things. You could probably do it in about an hour.

I'll try to send pic to Jaap since I'm not having much luck uploading. :homer:

 

back on the road :rasta: cheers andy

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The ID of the replacement spring (MG) is 20-21mm.

The wire diameter of the broken spring was 1.99mm.The replacement spring wire dia.is 2.15.(MG)

 

Being as how mine lasted for 26,000miles :blink: , that may be why I had a groove worn on the shift shaft.I don't know if this groove was present on any of the low mileage bikes that have been talked about.

 

as to a road side repair, well, I don't know about that. Yes, anything is possible, but I was in the shop and it was a major pain in the ass :angry: to get the bottom 3 allen bolts out. I think I would be more incilned to just cary a spare spring. If one did break, find the nearest accomodating motorcycle shop and tell them you have the part and the directions for replacement and see if you could help out.

The sharp edge of the shift plate gets chewed up straight away and certainly there is a groove by 1,000 miles

12spgouge.jpg-thumb_269_202.jpg

 

The biggest problem in relacing the spring is access to those lower screws. That's why I suggested modifying an allen key and carrying it in the toolkit. Not everyone will want to replace the spring themselves anyway and not everyone will want to do the job on the road, but it is what I will do if there is a 'next time'. If it happens out in the country you can have the thing repaired and be off on your way again, instead of the event turning into a long drawn out and perhaps expensive crisis.

 

Did you bend the new spring around the boss to check that it does not bind? It probably doesn't as the coil is now being made so much bigger. I think someone else posted that this bigger-coil spring is now being supplied as Guzzi's latest fix? And you say the wire is thicker too.

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  • 11 months later...
Guest mastiff2
Belfastguzzi, that was the best post I have ever read including the thousands on "pelican parts r1100s site".  thankyou.

26177[/snapback]

Thank you Belfastguzzy, you are saving peoples lifes! I just had my 01 V11 tranny recall done regarding the shifiting forks and they did not noticed the 16mm boss!!! I guess this mecanics are not very familiar with the bike! Thanks to you I checked the shifiting pawl and did the boss grinding/smooth the spring seat my self this morning took me 3 hours to complete the job! Much better than taking to the dealer again! I'm happy this bike is so easy to work on!

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Guest aironepony

Beltclasp,

 

An excellent, practical and comforting posting. Although I hope not to need your instructions on my 2004 Corsa; but you never know.

 

Many thanks.............. :thumbsup:

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I checked the shifiting pawl and did the boss grinding/smooth the spring seat my self this morning took me 3 hours to complete the job! Much better than taking to the dealer again! I'm happy this bike is so easy to work on!

56303[/snapback]

Prevention is better than the cure. I think that it's better to check this part and fix it, if needs be, than to wait for it to break on the road.

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Guest Nogbad

Does anyone have a good picture of a broken spring? Where the spring breaks will give a clue as to what caused it.

 

Those of you with spare springs, check to see whether there are any nicks or dents in the wire from the forming process. If the nick is in the right (wrong) place it can initiate a fatigue crack failing the spring after a given number of shifts.

 

My 2000 sport has done just on 10K miles now. Am I right in assuming the earlier bikes are less likely to suffer broken shift springs?

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Does anyone have a good picture of a broken spring? Where the spring breaks will give a clue as to what caused it.

 

Those of you with spare springs, check to see whether there are any nicks or dents in the wire from the forming process. If the nick is in the right (wrong) place it can initiate a fatigue crack failing the spring after a given number of shifts.

 

My 2000 sport has done just on 10K miles now. Am I right in assuming the earlier bikes are less likely to suffer broken shift springs?

56372[/snapback]

Yes. Pictures have been posted before and the subject done to death. Someone even proposed doing an electron microscope examination (or something similar, which of course came to nothing). Red herrings, all.

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  • 1 year later...

 

We're still interested to hear if there have been any/many problems with springs in boxes that have the correct sized 15mm boss????

 

Just for the record , where do you find that correct 15mm boss ?. Is it a regular part no and for which model/year. As well as how is it installed, just a simple replacement or a fill & drill situation ?

 

Thanks

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Just for the record , where do you find that correct 15mm boss ?. Is it a regular part no and for which model/year. As well as how is it installed, just a simple replacement or a fill & drill situation ?

 

Thanks

Any replacement parts from the factory should be 15mm. Somehow there was a supply of oversized parts that went into the circa 2002 bikes. Then they eventually realised and even later, it seems, had to admit to it.

It's a regular part for the V.11 6-speed boxes. The part number is in various threads and can probably be easiest found in the F.A.Q. forum. The boss is not a separate part. It's part of the pawl arm. So it's a simple replacement of the pawl arm. Again, pictures and parts diagrams are elswhere in Tech Topics and FAQ. (Ok: here are photos.)

 

Part in top left corner:

post-5-1068910851.jpg

You can see the spring and the coil that binds on the oversize boss, which stresses the hook end and causes it to break.

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  • 1 year later...

This is 2003 V11 Sport, manufactured in late 2002.

I'm in the process of replacing the spring a second time.

First time was at 14,000 miles and the tip broke off.

Thanks to Your help the shift selector arm was 16 mm,I had it machined to 15mm. I replaced the spring with an after market spring, which had the right measurement.

It just broke again, at 25,000 miles.

This one broke, in the top of the coil of the spring.

I just recieved 2 more springs, from Cannon race craft.

Looking for information on the eccentric adjustment screw on the transmition cover. Any information would be appreciated.

Charlie

sbrbygrace@hotmail.com

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