Detroit starter

Starters, especially on a Sixty series are the easyest to change of any truck and Shutting it off will not wear out you starter, the motor will start on it's second revolution.
If the starter does not work the fix is to bang you thumb, that does as much good as hitting the starter. If you beat on the starter the core may be rejected! 90% of the time it is a solenoid, bad batteries, bad cables, and the most common dirty connections.
Just a thought!

 

It's usually the solenoid, like JohnP3 said. Solenoids fail prematurely from low voltage caused by dirty connections, weak batteries and over cranking. Hitting the starter often can get you started, but it doesn't take much. I have had a driver hold the starter button (make sure it's in neutral), and bump the starter solenoid with a wooden hammer handle. Then get it to the shop to pull the starter.

39MT starters are much better than the 41MT's, plus no worries of getting core credit, since they are new.

 

I never leave my truck running while loading, thats just a waste of fuel and wear on your engine. On the s60 series you can see it. It doesnt look hard to swap out, but i know trucks have made it over a million miles before replacing the starter.

 

I always turn my truck off when stopped. always have. fueling, OFF! load/unload, waiting. OFF! one time I tried to start & heard nothing but a whizzing sound. took the back dust cover off saw the plunger was not engaging, with the key in the on position & a long big screw driver pushed in on the plunger & started the truck from under it. since then I got a spare alt off junk truck for 10 bucks, local neighbor, had it rebuilt for 45 bucks & keep it in side pocket for a spare. thought I really think a spare alt is more important.