My alternator possibly the whole motor has shifted(moved).

Now that you mention it, the spot on the fan that's rubbing looks to be smaller than the alternator housing, making what you say sound very logical.

 

In the 4th image it appears that the alternator frame behind the vanes has worn into the bar as well. Has this alternator been replaced before? Was it an aftermarket replacement?

If so, I have an idea that you might look into AFTER checking all mounting hardware for engine and radiator. (A bad mount seems MUCH more likely.)

If that alternator was replaced many months or even years ago, and the frame of the alternator was slightly too large, then after a couple years of rubbing, it might have worn and cut into the support bar far enough that the support bar started flexing more. That bar is almost certainly hollow. Likely around 1/8 inch wall thickness, maybe 3/16. It looks like the frame of the alternator has dug into the support bar by roughly that much.

Once the support bar is weakened structurally by wear on the wall of the support, it might bend far enough to start rubbing the alternator's vanes when the chassis is flexed.

Another **possible** issue to examine if the alternator frame has indeed worn into the support bar (and no mount issues are found) is that the support bar itself might be slightly curved, and **not** be perfectly reversible. If the bar was ever removed, and replaced, (perhaps for an alternator or radiator replacement) then it might have been flipped so that the curve pressed into the alternator frame, instead of being slightly curved out to give room for the alternator to fit properly.

This is coming from an experienced steel mill mechanic, not an experienced diesel truck mechanic. Without being able to put eyes on it, I might be blowing smoke.

EDIT: Note - the 4th image is available in the slideshow. You can barely see evidence of the wear I am referring to in the three images provided directly on the primary post.

 

Longer belts would get it closer to the bar, but like foolserrand said, the fins look like they have hit something besides the bar.
left rear motor mount will let the engine torque quite a bit that direction if bad or broken too, but there is still the fins.

 

That fin wear was what made me think it might simply be a problem with the support bar and alternator. If you look at the 4th image in the slide show, the frame of the alternator appears to have worn into the bar, and wear that slow would also prevent abrupt vane destruction.

If an engine mount fails, and allows a rapidly moving part of the engine to hit something solid, it's very unlikely that the damage will be highly regular wear patterns.

The more I think about it, the more I think that a motor mount allowing the alternator to brush the vanes of the alternator would lead to much more 'interesting' damage. I can still imagine a motor mount creating this wear pattern, but I think it would be much more likely that the alternator belt assembly would have fragmented, the shrapnel would have sprayed the engine, and loose belts flying around would have caused a great deal of damage to other motor mounted accessories.

 

On one of my series 60 engines, the alternator mount itself wore where the bolt went through it, letting the alt to get ####eyed enough that only one belt could be tightened on the pulley. It was not close to anything, so hitting anything was not a problem, but one tight belt was. the truck had less than 300,000 miles on it and they wanted 400 bucks for the mount. I cut the wore ears off and welded a solid shaft to it and drilled it for a new bolt, over a million miles since then and no more problem. lol

 

Yup. A worn bolt in a mount could easily create wear like was described, but I do not have the diesel truck mechanic experience to judge how likely a worn bolt is, compared to a sheared bolt or a missing bushing.

It's so frustrating to be unable to use the Mk I eyeball to see interesting problems like the one the OP is describing.

 

I will second that, I have a problem looking at pictures and diagnosing a problem, without seeing the whole picture, it is mostly a guess. lol
I owned a shop for several years, and it has slowed, but I still get calls wanting me to tell them what is wrong over the phone. lol Sometimes you can, others not so much, it all just depends.

 

I don’t get where you guys are claiming that it is a worn alternator mount, it isn’t a saddle mount alternator but a pad mount and if it was loose, then it would be a problem with the belt wearing out quickly but it isn’t.

The frame of the alternator extends a little past the fan blades of the alternator so if it really did hit the reinforcement of the radiator, the frame and the fan would show a sign of wear, but just the fan blades themselves?

I wonder what the other side or the underside of the alternator looks like, if there is anything that could be loose like a idler pulley bolt or something like that that can catch the fan blades only.

 

The fan blades look like they were chucked in a lathe and turned by a dull single point cutter bit, by looking at the chip trail and striations. Again it looks like a bolt head walked out of the front case long ago. The nose flange of that fan pulley isnt rubbed which i think would hit the support rod. But its hard to say without a birdseye view.

Yank the bar outward and carry on if the mounts are all good. Its just a bar. Just a hunk of metal to support a structure. Some other human thought it was a good idea at their CAD station. If you disagree, just change it. Its your bar. It exists to serve your will now.

 

Once again, I'm thinking the mounting ears on the alternator. Mine were broken but the belt didn't wear funny. When you pulled into a driveway, it would flex and the fins hit the frame. It was only an occasional problem and went away with a new alternator without broken ears.