The starter contact rebuild kits from Geno's are a great recommendation and have fixed many starting problems, but unfortunately they seem to be only available for '89-06' 5.9 Cummins.
I have a friend with a 2007 5.9 that had an intermittent starting problem and one time the truck had to be towed. The next day, of course, it started fine. He brought the truck to me and I performed voltage drop tests and load tested the batteries and everything checked out as it should. Any problem in the starter electrical control circuitry still needed to be addressed, but I told him that the starter contacts were likely to be the problem.
A reputable local auto-electric shop said that a number from the starter would be required to get the correct parts. I removed the starter (a Denso, but looked much different than I expected) and took it to the shop and this is when I found out that a kit was not offered. After spending much time researching, the shop representative found that rebuilt starters were available but most starters were coming to them as new - apparently to begin flooding the market with cores.
At this point the new starter was not purchased and I started to disassemble the old starter, but I could finish as it was beyond my capabilities and I did not want to damage it. I did notice that the internal contact parts that I could see were in good condition, so I put the starter back together and re-installed it.
I set up a remote jumper system directly from the battery to the starter so in case of a no-crank situation the owner could use the jumper to bypass the neutral safety switch and starter relay as a troubleshooting tool.
I went to the trouble of setting up the remote jumper system because I was not convinced that it was a starter problem. It turns out that a week later he had his automatic transmission serviced and the shop replaced the neutral safety switch because fluid had leaked into the electrical part of the switch and contaminated the contacts. The truck has been used for many road trips since the switch replacement and the no-crank condition has not been repeated.
Anyway, since the original post stated that it is a 2011 truck, there may not be a starter contact kit available and it very well may mean that a starter replacement will be expensive... all the more reason to take the time and diagnose the problem correctly.
- John