LM IV gearbox input shaft

[agmon1000]

Hi everyone,
For sometime now I had a feeling something is loose in my drive train on my 1985 LM IV.
I removed the bevel box and drive shaft but everything seamed normal, next I removed the engine and gearbox from the frame opened the gear box and there it was a broken spring on the input shaft.
I wonder if anybody seen this before, I don't do wheelies or abuse the bike in any form.
The bike only has 62,000 miles and except of this issue the gearbox internal are in really great shape.
I managed to find a used shaft on Ebay to replace the broken spring.

 

[lucian]

Belleville spring on clutch shaft,  Part #  13211500  is still available thru Harpers or Mg cycle, Maybe worthwhile to go with a new one although not cheep at 58 dollars plus shipping, You may want to replace the shift return spring ( part # 28238261) while your in there as they have been known to fail on the early five speeds. Also  search for Pete Ropers tutorial on proper shimming of the shift drum on the five speed box.

Here it is https://www.thisoldtractor.com/guzzitech.dk/pdf/gearbox-shim-pete-roper-new-tools.pdf 

[Groover]

Good  tips from Lucian

[moto-uno]

  That same spring broke on my Le Mans 2 about 5 years after purchase . The replacement has gone over 200,000km and
been trouble free . In those later years it when through numerous performance enhancements and a wee bit of abuse :) .
And as has been previously suggested , do replace the shifter spring , way too much trouble to go in again for a $5.00 part !
Peter

[agmon1000]

Thank you very much for the advise.
I was looking at the shifter spring it looks like it has been replaced to the upgraded version with the 3 coil spring.
Thanks again


download full resolution instagram photos

 

[Old Jock]

Buddy told me his broke on a tuned proddie racer, but that's about all I know

It does happen but thankfully a rare event

[Wayne Orwig]

Belleville spring on clutch shaft,  Part #  13211500  is still available thru Harpers or Mg cycle,

Can the Belleville springs be installed in place of the coil spring?

I'm not sure what it would take to compress those things though.

[Groover]

Your red Le Mans represents the Le Mans 1000 design very well, nicely done. What are the wheels and forks and how did you make it all work (details, tires sizes, etc), and why does it look so good? Please explain 

[lucian]

Can the Belleville springs be installed in place of the coil spring?

I'm not sure what it would take to compress those things though.

I'm not sure why it's referred to as a belleville spring in the MG parts fisch. I guessing because of it's square cross section through its coils.  It is certainly different from a true belleville spring as in the washers. I do think I would spring for a new one though. ( no pun intended) 

[Wayne Orwig]

I'm not sure why it's referred to as a belleville spring in the MG parts fisch. I guessing because of it's square cross section through its coils.  It is certainly different from a true belleville spring as in the washers. I do think I would spring for a new one though. ( no pun intended)

Newer models actually do you a belleville spring stack. I'm not sure when it changed.

[agmon1000]

Your red Le Mans represents the Le Mans 1000 design very well, nicely done. What are the wheels and forks and how did you make it all work (details, tires sizes, etc), and why does it look so good? Please explain 

Thank you for the kind words, I did the mode back in 2011, its a complete front end with 3.50x 17" wheel and 320mm brake disks from 2007 Suzuki GSXR 750, I had to transfer the Guzzi steering stem to the Suzuki triple tree, machine shop made a bushing for me to compensate for diameter difference between the stems and the Guzzi stem can be pressed in to the Gixer triple tree.
The rear is 4.50x17" from 2001 Moto Guzzi V11 sport. The new rear wheel was 20mm off center to the left (looking from the rear) with the original swing arm and there was no way to center the wheel so I replace the swing arm to late model California with the wide swingarm to center the wheel and accommodate the 160 tire.
That was my cost effective solution without getting into expensive swingarm mode or getting the wheel modified.
As far as the wheel base goes what I lost in the front I gained in the rear so its few mm longer then original but shorter then California.
The front end is wider and I don't need the steering damper anymore also the clip-ons are wider and its very easy to steer the bike.
I am very happy with this mode and there are many tire choices, now I have Michelin Pilot Road 4.
The only thing I lost about 15MPH off the top speed because of the smaller tire but she off the line like a bat out hell.
8:33 final drive will take care of that but I am not going to bother with it.
Now the bike is totally disassembled, I am refreshing the top end on the engine new valves, guides, valve lifters including new timing chain and tensioner.
frame needs new paint and the wheels are getting painted also.
It will take some time until the bike is back on the road so for now my Kawasaki KZ1300 is getting exercised every week 

[Groover]

Great details, thanks for that. Did you use the up to 2001 EV swingarm, or the 2002-2004 with the double knuckle? Any photos from the side? Nicely done, I think it's all that model needed to be just right.