Rocker arm bolts

Company got this truck from another location. I've been driving it for 2 weeks. 2010 Transtar Maxxfocre 13. I'm taking it to the dealer in the morning for a oil leak in the front of the engine. I got the vehicle information print out, we had them run the vin#. The vibration damper has top^top written in big white letters, certainly not factory marked and oil is laying up in that area. Not sure if they were marking for TDC or it the crankshaft seal been replaced. Here's my question. They rocker arm bolts have been replaced 3 times within a 3 month period. A few months after that cylinder head bolt and a few months later the rocker arm gasket cover. Any ideal on work they did, nothing in the report about what the actually problem was. Replacing the engine brake? Also the stop engine warning has come on twice, yeah, it's losing coolant, about a half gallon a week, can't find a leak so assuming EGR cooler again. That will be the 3rd replacement for this truck.

 

Yup, I've had to mark them myself. My knowledge is on Marine engines back before all the computer crap messed up a hard working diesel engine. No computer fault code back then to tell you what was wrong. 16 cylinder Detroits, 903 Cummins, PTO's that actually ran something useful like dewatering and hydraulic pumps, raw and fresh water systems. I've never had to replace rocker arms bolts like that. I need to upload pictures of the two 1947 inline 8 cylinder 71 series we had on the cableboat, two side by side banks running into one red gear one port side, one starboard. we replaced them, finally in 1994. Nothing left to rebuild.

 

The only thing I can think of is they over torqued the bolts and they cracked.