How did my 2003 Ram throw a rod?

Purchased 2003 Dodge Ram 1500 with 93,000 miles. Oil gauge was erratic, had to turn truck on and off and on to get it to engage. Checked oil and ensured that it was filled properly each weekend. Used to help pull heavy stumb which it did easily and to pull other truck out of mud … again, did not seem to strain. On 14th day threw a rod through the block while driving 45 mph on slight incline. Possible causes??

Clearly the cause of the failure was operator error.

The oil gauge you were reading was not oil level, it was oil pressure.

Apparently it was correct. There was not enough oil pressure to keep the engine lubricated so the rod left the block looking for more oil.