signifiant slop/lash in drive train, fear of failure

[Dazz]

greetings,

 

I haven't been around for several years because of health issues, things are improving and I've returned to one of my passions,

motorcycling and specifically on my 2000 V11 sport.

 

I purchased the bike new and went through all the teething problems, including having the clutch replaced at 15,000 miles because of 

a rivet failure. This happen at Deals Gap, in North Carolina, about 800 miles from where I live in NY. Limped home and had the clutch replaced.

 

So the problem is the amount of "free play" in the drive train, especially evident when sport riding in lower gears and going on and off throttle.

I realize lash is an issue with v11's, but it's getting worse and I fear on the road failure.

 

With my bike on its stand and bike in gear, I can move my rear tire 2 1/2 " measured at the outside edge of the tire, when looking at the drive shaft I can detect about a 1/2" of free play travel.

 

When moving the tire back and forth you can clearly hear it connect, its a loud metal on metal knock.

 

I know it's not the bevel drive, and I don't believe it's drive shaft alignment. The noise when it connects at the end of the free play come from

the engine case area.

 

Any help, suggestions, discussion would be appreciated. 

Thanks

 

 

 

 

 

 

 

[docc]

Hi, Dazz!

 

Your Sport definitely had the recall work done to the gearbox? (The gearbox internal cushdrive was part of that).

[Dazz]

Hi Docc,

 

yes it had the recall work, I didn't realize there was a cushdrive in the gearbox nor that it was a part of the recall. does this sound like the type of problem

that a poorly functioning gearbox cushdrive would exhibit?  

[andy york]

Hey Dazz,

I would expect there to be more "slop" in the Guzzi than a chain drive bike.

You have your six speed transmission that is going to have a bit of back and forth "slop"

running down the driveshaft that has two u-joints that should not have much "slop"

back to the "rear end "gearbox that will have a bit of "slop" in it.

How many miles?

You should have magnetic drain plugs on both the tranny and the bevel box. 

First thing I would do is drop the fluid in both of them and check the drain plugs 

for debris.There will be some "grit " as I call it....almost like a metal powder.

All normal.

If you find something bigger than say a bb or a couple of pieces bigger than bb's

then I would pull the side cover off of the tranny and have a look see.

I've got 100,000 miles on mine ....original clutch,tranny,driveshaft,bevel box.

I don't drive like a wussy either.

Let us know ... 

[Dazz]

Hi Andy,

I'm pretty sure this is more than the normal amount of free play movement, but would love to have confirmation. The bike has 25,000 miles on it

most put on before 2005. Everything  seems to be snug, driveshaft, uv joints, bevel box. The onset was at the time of my clutch failure,

it's possible I damaged more than the clutch. The clutch had started to act up at Deal's Gap, I continued to ride the Gap, repeatedly, and ride home

another 1000 miles.

 

One thing which would help me would be if anyone would check the amount of movement, with the bike on a stand, in gear and measured at the outside edge of the tire.

as stated mine moves 2 1/2" and there a distinct metal to metal knock coming from the engine housing.

 

I do plan on getting this resolved, and Andy I would love to see 100,000 miles on my V11.

[docc]

I just check the play from the movement at the outside edge of the rear tire on my 86,000 mile Sport:

 

2 1/2 inches! With the same end point sound you describe.

 

Looks like you're in spec!

[Dazz]

wow, thanks docc,

God now I have to find something else to worry about.

I really didn't expect others would find as much.

a real relief. 

 

still would like to know why this much play.

and what is the metal to metal knock

it's not bevel box, uv joints or drive shaft.

[gstallons]

Go over every fastener that holds the driveshaft onto the splined shafts to see if they are loose. Jack the bike up off the ground and jam a screwdriver in the driveshaft at the rear u-joint and see if there is slack. Move to the front u-joint and do the same thing. If they are o.k. the problem is in the engine... Good luck !

[Dazz]

thanks for the response gs, 

I started by poking, prodding, pulling, shaking, physically checking the drive train to find the source. It's not in the drive train after the first uv joint.

Now that docc has checked and confirmed that his has the same free movement and metal to metal contact noise it puts my mind more at ease,

but still I have questions. What's going on there, what in the out put shaft- gear box could allow this extreme amount of free move. What is the metal

to metal contact noise about.

 

One more confirmation would be a big help. All it takes is one motorcycle stand and 30 seconds to move the wheel back and forth with bike in gear.

 

Most of my rides have some sport riding involved, tight switch back turns that require on and off throttle in lower gears produce a significant slamming

effect. If this is common with all v11 sports, I would like to know. But my bike didn't do this for the first 12,000 miles. 

[Tom M]

Hi Dazz,

I'll check the rear wheel slop on my bike and get back to you in a day or two.

 

Something that could have changed on your bike is the rear wheel's cush drive may have frozen.  If you perform the mods suggested in this thread you will feel less drive line shock when shifting.  It won't reduce the lash but you won't feel it as much.  http://www.v11lemans.com/forums/index.php?showtopic=11820&hl=cush

 

I find my bike works best when I accelerate, brake and shift smoothly.  When I rev match on downshifts while easing the clutch lever out I don't really notice the lash at all.  If I don't rev match and snap the clutch out it's feels clunky.

[mznyc]

Dazz I'm in Ulster.I could ride the Scura down and we could A-B them side to side to see if there's a difference.I have about 19K on her and had the driveshaft disassembled,inspected and greased several hundred miles ago and it feels good to me but have nothing to reference it to.

Michael

[stefano]

  i just measured my '02. it's also about 2 1/2 " or 63 mm or so. all 6 gears the same.

   also the clunk at end of slack.

   when i bought her years back, this slack produced a lot of driveline snatch in the lower gears.

    i read (somewhere on this forum i believe) that these bikes reward smoothness. and i found this to be very true

  cheers, steve

[GuzziMoto]

My take on it.

The gearbox has gear sets that link together with dogs (little protrusions) and slots. The slot is much bigger than the dog so that at speed the dog can find its way into the slot. That means the dog can move back and forth in the slot. Some gearboxes have more dogs and slots, others have less. The arrangement of the dogs and slots determines a number of things, like how easily the bike shifts and how much power it can take with out breaking. It is a trade off, gains in one area mean less in another.

That, plus the combined gear teeth slack through the driveline adds up to a fair bit of slack. But Guzzi is not by itself here, other bikes also have slack, some more some less.

[Dazz]

Thanks for all the responses,

with 3 bikes all exhibiting the same free movement, I will go out on a limb and suggest that one connection in the output gearing is

where all, or most of the infamous guzzi drive train lash is generated. This may be obvious to you but  for me this helps. The slop is built in, and the cush drive 

of course softens the slam of one set of out put gears. forgive my lack of correct terminology.  

 

Still seems like a hell of a lot of free 'no load felt' movement before the gears connect. A hell of a lot of clearance built in.

 

Please correct me if I assume too much.

 

Michael would enjoy meeting up somewhere like Harriman Park in the future, right now I'm still working on straightening out my health issues.

thanks though.

[docc]

That freeplay is a nasty booger in the very tight stuff. Very hard bike to ride like that next to the pert little chain drive sporties.

 

Makes proper men of us, no?