It's an old time trick that does a pretty good job of cleaning pumps and injectors as ATF is pretty high in detergent properties. It's not good to run it all the time as it will leave an ash deposit behind on the injector nozzles. I think on a new diesel with DPF and SCR it would be a really bad idea to run it at all for the same reason, ash.
This is what I'd suggest. I wouldn't try it on anything designed with any type of catalyst. I assume a 2010 medium duty rig has a lean nox trap if it doesn't have SCR. Definitely don't put it in anything that has a DPF.
