Front and rear sprocket bolts

[minnesotamonster]

Just picked up an s4r and noticed a few missing things 

Missing a bolt in the rear sprocket



Anybody know the part number? I downloaded the parts diagram from ducati but am not seeing it in there.


Also, the front sprocket is missing both its retainer bolts, not sure what they are called.
And the weird part, which is probably why the bolts aren't there, is the clip doesn't line up with the holes in the sprocket.

Here is a pic, kind of hard to see, but no matter which way you put it on or twist it, it will not line up.



The sprocket has the clip outline on it in the correct position, so it must've lined up at one point.

What's going on here 

I thought the clip might have been worn out, so I took the one of my 600 and tried to put it on there, but I had the exact same issue, so I do not think it is the clip.

ANY help is appreciated.

Thanks!

[Ducatl]

Shouldn't the clip slide in and then twist to the correct position? That's how I remember it the last time I took it apart anyways...So you slide it on, twist it, and then it's not lined up? that what's happening? maybe that sprocket isn't the correct one for that bike? not sure if they changed the spline count or size between years.

[Speeddog]

AFAIK, that spline has been the same for a *long* time.

Like Ducatl said, the plate goes on, then fits into the groove and can be rotated to make the bolts line up.

That's an aftermarket quick-change sprocket setup.
It looks like an AFAM unit, but could be another brand, I think there's a couple that are similar.
Just pull out one of the other bolt/nut sets, and buy another of the same.

[brimo]

I thought the S4s had the one big bolt and the s2s had the 2 little ones like in that pic.
If I'm wrong (and that is possible  )  looking at the shaft there shouldbe a groove that the plate sits in so it can rotate to line up with the sprocket holes.
That said, looking at that pic  it does appear that even if you rotate that plate the holes will not line up, any how, get it fixed and don't ride it till you do, that sprocket working it's way off could cause catastrophic damage to your bike and you.

[Speeddog]

According to the parts catalogues, the big nut setup didn't start until the Testastretta S4Rt and S4Rs.
S4 and S4R had the plate setup.

I'd say *something* is haywire, from the looks of that rear sprocket.

There may be another manufacturer besides Ducati that uses that same spline.

[minnesotamonster]

Shouldn't the clip slide in and then twist to the correct position? That's how I remember it the last time I took it apart anyways...So you slide it on, twist it, and then it's not lined up? that what's happening? maybe that sprocket isn't the correct one for that bike? not sure if they changed the spline count or size between years.

yes, that's what should happen, but no matter which way you rotate it, it will not line up. I'm so confused. So I can get the rear bolt at any hardware store? Easy enough.

Speeddog, what do you mean something is haywire with my rear sprocket? As far as I can tell the rear looks fine except for the missing bolt. Maybe I'm missing something.

Thanks for the input so far.   

 

[Speeddog]

Maybe I'm reading too much into the picture, but it *looks* like there's a lot of wear on the side of every second tooth.
That would mean there's a chain/sprocket alignment problem.

[minnesotamonster]

Gotcha. That would make sense since there is nothing holding the front sprocket in place lol.

So why isn't my clip lining up? Wrong sprocket? But there is an outline on the sprocket of the clip in the correct position, so that would indicate the sprocket was correctly installed at one point, right?

[Desmo Demon]

Maybe I'm reading too much into the picture, but it *looks* like there's a lot of wear on the side of every second tooth.
That would mean there's a chain/sprocket alignment problem.

There is an alignment problem because the front sprocket is being allowed to walk back and forth on the output shaft. In the picture, it looks almost like the groove for the retainer is on the outside of the front sprocket, but I'm not too sure. If the sprocket travels in toward the engine, the misalignment will cause wear on the outside of the teeth on the rear sprocket, like what appears to be the case..

You need to move the front sprocket to expose the groove in the output shaft and rotate the retainer to align the holes with those in the sprocket. If the retainer will not rotate, it is probably because of the teeth on the retainer or on the output shaft are chewed up. The retainer is hardened, and so is the output shaft, but the retainer can chew up the splines on the output shaft...it's happened to me. Sometimes it can be difficult for the retainer to rotate, but it is suppose to. Basically, the teeth on the retainer will line up with the teeth on the output shaft once rotated (teeth butting against teeth so that the sprocket will not walk).

Yes, the quick change carrier on the rear appears to be of an AFAM design. Sprocket Specialists made a similar QC carrier (the sprockets are interchangeable). The bolt may or may not be a standard bolt. The bolt on my Sprocket Specialists carrier on my 748 is a speical bolt. You may be able to get a regular bolt and grind it down to fit in the recession in the back of the QC carrier if it is a different design than just a regular bolt.

Also, when you go to replace the bolts in the front sprocket retainer (edit - M5 bolts), make sure you degrease the threads in the sprocket with a cleaner, let it dry, and use blue Locktite on the bolts. If you do not buy the bolts from Ducati, get either Grade 8 (I forget what the value is in metric) or a stainless steel bolt. If you get the el cheapo bolts, you may get the ones that will shear the heads off when you go to torque them down or when you go to take them back out.

I hope this helps.

[minnesotamonster]

Thank you! I just realized how stupid I am. I need to pull the sprocket out and leave the clip in the groove and align it there. The sprocket was way over by the engine causing exactly what you described. I got confused because it usually isn't way over there and couldn't figure out how to get the clip over there. Wow what a brain fart. Sorry for my stupidity.

If the rear sprocket bolt is a special one can I order them from afam?

[Desmo Demon]

Thank you! I just realized how stupid I am.

I come to that realization far too often about myself. 

If the rear sprocket bolt is a special one can I order them from afam?

I'm sure that whoever the manufacturer is, they will probably be more than happy to sell (or give) you another bolt. I'm not too sure where the marking will be to see who the manufacturer is, but you may be able to find one if you clean off the carrier. You may also be able to look through the rear wheel and see what those bolt heads look like.

[minnesotamonster]

Stopped at a hardware store over lunch. Got a couple stainless m4 and m5 bolts ( the m4s looked too small, along with a couple lock washers. Hopefully this tajes care of it and my alignment problem. Just need a bolt for the rear sprocket now  [moto]

thanks guys!

[corey]

let's all just stop for a second and thank the moto-gods that this stuff wasn't lining up properly because of a bent output shaft.


moving on...

[Desmo Demon]

Got a couple stainless m4 and m5 bolts ( the m4s looked too small,

I'm home, now, and measured them. They appear to be M5, as you expected. I edited my response above to reflect this.

[minnesotamonster]

let's all just stop for a second and thank the moto-gods that this stuff wasn't lining up properly because of a bent output shaft.


moving on...

not cool

thanks 
I'm home, now, and measured them. They appear to be M5, as you expected. I edited my response above to reflect this.