alternator bolts

[foton]

on my 2017 wacker -neuson sw-20 the alternator light came on , so I went to the back and checked the battery with a voltmeter it had just over 12 volts . So when I looked up I saw the alternator vibrating and a bolt head was gone. So I turned the machine off and took off the belt guard and saw that both bolts were sheared off, luckly I was able to use a left handed drill and remove both broken pieces out of the engine. I called wacker and asked them if this was a fluke or was there a service note on this issue they said no, they never heard of this happening. So I would like a opinion ,were the 8mm x 1.25mm bolts used to hard making them brittle and shearing due to engine vibration? The piviot bolt is a 12.9 temper x about 70 mm long ,the locking adjuster bolt is a 8.8 about 25 mm long. I have never seen this before ,I had some bolts that were the correct thread so I was able to move the machine back to the shop. But before I buy back factory bolts I would like to hear some opinions.

 

[mrbb]

just my 2 cents, but there would have to be some serious vibration for it to damage a bolt, and if it was that bad, Id say you got bigger issues some where causing the vibration, and other things would be at risk sooner than new bolts

I would think standard grade 5-or 8 bolts would be fine and should last a LONG time, I'd put a little anti seize on things when re installing them!
and if one was maybe super worried about vibrations, I am sure one could look and find some HD rubber washers to put between things
or if one was creative, could find some USED rubber motor mounts and make your own! or the likes!

but again this is just my 2 cents!

 

[foton]

you know I thought the same thing, I checked the engine mounts all good there,and when it is running I do not see any more thatn normal vibration, the machine only has 450 hrs. on it. I guess I will order new factory bolts and just keep a eye on it. and yes on the never seize already on there. I have no engine or other systems alarms on so I assume it is running correctly. The only thing I can think of is that maybe it was not torqued enough and in the was not held against the attaching points tight enough and vibrated enough because of that to fatigue crack.

 

[mrbb]

you know I thought the same thing, I checked the engine mounts all good there,and when it is running I do not see any more thatn normal vibration, the machine only has 450 hrs. on it. I guess I will order new factory bolts and just keep a eye on it. and yes on the never seize already on there. I have no engine or other systems alarms on so I assume it is running correctly. The only thing I can think of is that maybe it was not torqued enough and in the was not held against the attaching points tight enough and vibrated enough because of that to fatigue crack.

that or just had some bad bolts from the factory, every company gets bad something now and then

and odds are it could be cheaper to just buy new bolts else where of same size
OEM parts on bolts tend to be way over priced in my experience!~
and there is no shortage of places on line that sell bolts these days, as well as most GOOD hardware stores and likes!

 

[foton]

yeah maybe I will just leave it as is with the bolts I had on hand in there and see if they hold up.

 

[haymaker]

I would make sure the bolts you have are grade 5. Dead soft bolts could have threads stretch from tightening or vibration, making them a bear to get out.
Soft is ok for emergency use but grade 5 or even grade 8 (if that is what they are specified to be) would be better. Just my 2 cents as a 40 year tool and die maker.

 

[foton]

I suppose you are right I will take the metric hardness numbers an see if I can find some .