Knocking and metal shavings in oil

Have been working on and off on the bike for a while now. Ohh btw, my trusty ST is now an official project bike. Got the engine out with the help of a friend over the weekend. I think I found out the culprit. The alternator shaft has snapped off. Couple of pictures attached.

As we say in Oz, thats a Bugger.

I bet that the alternator seized, you would have felt that if it happened. Guess you could proceed with the engine swap, or replace the alternator..

Thanks for the follow up.
Sorry about what U have found. This is the 2nd 1. Terrys bike had the same problem, Gears & bearings in the reduction for the alternator.
U will need to replace the engine.

Sorry to hear your bad news

I'm assuming the alternator bearing has failed causing it to seize?

Is this a common problem and does it always result in the need to change the engine?

The oil that runs through the alt. is 1 in the same for the engine. The left over metal crap is more than likely in & all over the engine galleys? U might get away with a quick clean and flush, change the alt.?
Me, I ride to far.
I don't know why the local mechs. don't drop the oil pan. I have dropped my ST pan 3 X's now. Clean the 2 pump screens. Take a mirror & light U can see the rods Bottom pistons & cylinder walls

Wow that is a major failure there. Good luck with the repairs or motor replacement.

Curious as to why it snapped off. Does the alternator spin? If so my guess is just an undetected flaw in the shaft. If frozen then that may explain the snap.

Hoping your oil filter caught most of the particles before it went into the galleries.
Change your oil a few times, say the first oil change after running it for 5 minutes, second oil change after running it for a few hours and then run it for 500 miles. New filters on each oil change.


Then send that 500 mile oil change out for oil analysis to

http://m.blackstone-labs.com

Best of Luck

Yea, I'm thinking of doing an engine swap. Too many bits were found in the oil when my mechanic drained the oil and I found a bunch of what appears to be ball bearing bits by the alternator shaft.

Any advise on what I should replace and check for wear since I have most of the bike parts laying around ? BTW, i ended up taking swing arm out as well to get at the engine.

Thanks all for all the input and the support. Learning a ton from reading the posts on this forum. The info in this forum is extremely useful.

It's a standard ST '06. I bought it used in 2010 from a forum member.

Finally done with the engine swap and put the tupperware back on today. My trusty ST is back on the road again.

Cheers,
Rafi

That's great!


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That is great news that you were able to change out the motor and get the ST back on the road. Now it is time to enjoy it.