My 6 month old Motorguide Bulldog shaft appears to be corroding, although it is supposed to stainless steel. It looks more like aluminum that has come in contact with a caustic subsrtance. I'm not sure how to explain what I am seeing and hope the pictures better explain. It also looks like how some metals discolor when they have been heated up - although I am not aware of any issues. The motor worked fine yesterday. Always in fresh water, never salt.

Has anybody seen a stainless shaft do this? I thought maybe it could be water getting up under some kind of clear protective coating but a closer inspection doesn't look like this is the case. I don't recall any of my past trolling motors doing it.

I'd love to help but I'm not a metalurgist and I'd be talking out my rear end.  Is it rough and/or pitted?  Do you anticipate problems?

It is not rough or pitted, but since it is only 6 months old it is possible it is heading in that direction. I've only recently noticed this. My concern is that I perhaps have a defect in either materials or protective coating(?) or even an internal problem with the wiring/motor that could be causing this. Unfortunately I live in the stick and the nearest repair facility is over a mountain range and an hour away.

Looks like hardwater stains to me

Looks like hardwater stains to me

Yup sure is mine does the same thing elbow grease will take it off

It's in warranty - take it in for service.

Don't take it in until you try to polish that. You will seriously get an "Are you a moron look" from the mechanic or service man if that is really just stains like the first guy said. Its probably just stains from the water you fish, like gas&oil residue + dust. If you have any clay around that can also make some stains that don't really look like dirt. If after wiping it with soap and water and trying to polish it you still have that look then maybe you could say its something wrong with the metal, but I'm willing to bet that in 5 minutes you'll have it back to that out of the box shine.