[AusMV312]

My '08 312R has the dreaded alternator gear rattle and was wondering weather to try and fix the issue as it's getting a little embarrassing in the pits on track days. People looking sideways at the bike and moving away slowly expecting something to let fly at any moment.
I appreciate the engine noise of the MV's and owned an SS Ducati for 16 years so healthy noise is great but this is kinda going over the line a little. So is it worth me going to the trouble, is it going to be a pain in the arse to do, should I raise the bar on my "acceptable engine noise".
As per the threads on this issue the noise reduces when the fan cuts in and disappears when above 2000rpm.
Appreciate some advice, Thanks
Steve

 

[theknurl]

?

My vote? nut on the end of the alternator is loose, letting the paddles of the cush drive flop around
At speed it takes a torque set and doesn't rattle
Page G14 of the parts manual

To remove alternator, remove starter 1st

:wink2:

 

[AusMV312]

Thanks Noel. I'll begin with that and return with the outcome. Got a bit to do so will be a while.

 

[theknurl]

?

Steve;
It could be the inner half of the cush drive too.....
Chris Wells posted about alternator removal....
You must remove the starter 1st and then rotate the alternator to get it out

For another reason I pulled the motor so removing the alternator was easy

:wink2:

 

[AusMV312]

Steve;
It could be the inner half of the cush drive too.....
Chris Wells posted about alternator removal....
You must remove the starter 1st and then rotate the alternator to get it out

For another reason I pulled the motor so removing the alternator was easy

:wink2:

Do you think swinging the frame up off the motor will make it far easier and worth the effort? Sorry Noel, I'm probably asking the bloody obvious but I'm sitting at the computer now and haven't been out to look at the bike.

 

[theknurl]

?

No, I'd just pull the starter, then the alternator and drive

:wink2:

 

[style_one]

be prepared. it can be a real pain in the @$$. just be patient.

 

[AusMV312]

OK, I'm underway pulling the alternated out. I'm at the point of trying to pull and rotate the alternator but am finding it difficult to remove..... Virtually zero room in there.

 

[AusMV312]

Just sliced the alternator O ring in two putting the alternator back in situe. I think I'm going to have to swing the frame guys.

 

[theknurl]

?

You didn't remove the starter.........

Chris Wells posted about doing it that way

:wink2:

 

[AusMV312]

You didn't remove the starter.........

Chris Wells posted about doing it that way

Gidday Noel,
Yep, I pulled the starter

 

[AusMV312]

Can I have the link to Chris' post?

 

[theknurl]

?

Sorry, no link, search "alternator removal " or Chris's posts

:wink2:

 

[AusMV312]

OK, swung the frame and pulled the alternator. I have discovered that the inner hub that houses the cush drives is wobbling about and the centre bolt is wound out. Not nice. I have found a peice
of bearing casing also. See photos.
Best way to stop this reoccurring...correct torque and Loctite?? I see that there is no washer with the centre bolt.

 

[AusMV312]

I'm going to replace the bearing...should I replace with same bearing (SKF EXPLORER 6005 ???D) or is there a better quality option?
Appreciate the advice.
Thanks

 

[theknurl]

?

I'd go with a sealed one since the broken pieces of the bearing cage were floating
around

sealed 6005-2RS

:wink2:

 

[AusMV312]

Thanks,
Any suggestions on how to prevent the centre bolt from winding out again?
Or maybe, why it did it in the first place as the alternator rattle has been mentioned a few times in the past on this forum and it has been said, that it's nothing to be concerned about etc.
I'm sure glad I investigated the issue.

 

[AusMV312]

Purchased and fitted an NSK sealed bearing $8.50AU. It was very easy to remove and re-fit with some heat on the casing. I have used 'strong' Thread Lock on the the Cush Drive Hub centre bolt and torqued it to recommended 25nm.
I'm wondering whether I should put a lockwasher of some sort with that centre bolt. I'm at work for a week so I'll make a decision when I get back home.
Any opinions out there....?

 

[silentservice703]

Since you are using Loctite you shouldn't need a lock washer.

 

[AusMV312]

Loose Again!!??

OK, so it's been nearly 12 months and a few Trackdays under my belt. I've had to remove the alternator again due to an oil leak coming from that region and my assumption was correct that "O" ring had failed. No problem, replace "O" ring.
I checked the Cush Drive centre bolt and Hub (Engine Side) and it was loose again:surprise: The centre bolt was not finger tight this time so the Thread Locker I used half worked as there was slight resistance as I unscrewed the bolt.

I'm figuring there's an engineering issue with the design of this component regarding surface area. If you look at the contact area of the head of the bolt to the hub it may be just 50% which I think is the problem.....Any thoughts from the great minds that lurk in this Forum.



These photos are well within the limits of the website requirements but they look huge on the preview on my computer.... hope they adjust folks