96 f350 starter issue

Trouble with the f350 dump truck again. Yesterday, it had very slight hesitation when starting, but took right off. Drove home parked in driveway, tried to start later and only heard solinoid click.
So i guessed it was the starter,replaced and it took right off but had a pronounced "zing" noise at the end. Ive heard vehicles do that before so i thought it might settle in.
Today took it out started probably 3 times and on the next try "click, click,click" Well as it happened i was directly across from a independent shop. Since im not the most savvy mechanic if figured my attept to repair was done wrong so let the pros do it.
So they found the starter was loose and an improper bolt was used and the tourqe broke an ear off the starter.
They put on another new starter, started it several times and i drove away happy. Went about ten miles stopped for gas and guess what " click, click,click".
A passerby stopped had tools loosened one started bolt and wiggled the starter and we're running again

So whats going on ??? As i understand it this starter is not shimmable. I plan to get it back to the pro guy but was looking for some ideas.

Thanks Chris

The most likely is a bad battery connection. A ground from the negative terminal, or even the battery terminals themselves. Cables can go bad internally and appear good from the outside. Wiggling on, Clean and bright all connections where big cables are attached. Jim

Double check the ground and power wire connections. When I had my 96 F350 dump I had this issue and it turned out to be corrosion.

You didn't mention the engine that you have in your truck, but some Ford engines take a different starter, depending on if you have an automatic or a manual transmission. Double check to make sure the parts man got you the right one.

I second that

Definitely a grounding issue. I'm betting the service guys didn't brush the all dirt and grit away, depending on the bolt threads alone being "clean enough" - as if they were all that mattered. Since it started before the new one, check it all. Corrosion and breakage happen inside the insulation on cables, too.
Been there.

Might want to look at your neutral safety switch as well.