So, after 6 weeks w/o my truck not running, and taking matters into my own hands, I reached out to the parts department directly and egged him on to find me a starter from a local dealer's inventory and got my truck back just in time for Christmas.
I paid for the core charge to take my old starter and do some investigating and as a GM man, one of the first things that struck me as odd was the fact that the starter bolts to the transmission bellhousing and not the engine block. Which seems incredibly odd and curious and has me thinking that the starter is now looking to ground itself through the transmission. Which means the transmission ground wire is now responsible for grounding the starter properly. Seems like an unnecessarily long path to take to ground a high amperage draw component. Further, as you can see from the front facing surface, the mating was not perfectly flush or sealed, and corrosion worked its way in. Hopefully in the near future I'll get around to testing this starter and or having it torn apart and analyzed.
Pretty sure the reason it's done this way is because it's a ZF supplied transmission and mounting to the bell housing is a more of a "Universal Design feature" to make their transmissions more modular from everything BMW to Volkswagen and RAM. I'm no metallurgist or electrician, but the design seems quite flawed considering there's an iron engine block right there that is a lot more conductive than an aluminum starter face mounting to an aluminum transmission that itself has electronic components within, electrical charging/conducting through a lot of fluid surrounding it. I wonder if aluminum block Hemi's are going through starters as frequently. Or for that matter, the aluminum block Pentastar v6.
Unfortunately, because I paid the dealer to do the work, I couldn't get in there to do a little preventative maintenance such as sand down the surface of the bell housing and maybe even add some spray paint or sealant along the top mating surface. I'm going to look further into how the transmission case is grounded and see if any grounding assistance can be given there as well.
Based on how the starter is installed, it seems that the corroded side sits outboard. So any water, rust from the engine or exhaust manifolds, salt and corrosion from the road, Etc would splash up on there, run down along the mating edge, and then be given a nice baking from the catalytic converter and basically just erode its way in. As opposed to a GM starter setup which would a) would be shielded from road debris/top engine flaking surface run off and b) have the mating surface at the top of the starter where liquids would always run off and or be blown by the spinning flex plate. Maybe a starter Shield that stretches back a little bit further to also keep the front prop shaft from spinning toad water onto it?
. Had a new battery put in 3 days ago but didn't change anything. I checked and my mopar starter looks the same as your pics as far as corrosion etc. I bought a new starter as I need my truck to work and just want the quickest way there...so I'm hoping this will work. I feel your pain - love the truck and baby the hell out of it (changed all fluids myself, tune up, etc). This issue will be the death of me if the starter doesn't work. 
Let alone risk the dealership claiming that an improved grounding system is to blame for other issues that may arise. So I think I'm going to look into double grounding all the contacts I see, so is not to cut up any looms or take apart in place harnesses.
Let alone risk the dealership claiming that an improved grounding system is to blame for other issues that may arise. So I think I'm going to look into double grounding all the contacts I see, so is not to cut up any looms or take apart in place harnesses.
