I was doing some research on helper springs for my ram 1500. There are basically 2 types the cheap inside the coil design and the heavy duty air bags that replace the bump stops...all the heavy duty air bags I can find seem to be rated to 5000lbs. If I installed these couldn't I easily over load my axle and cause a failure without knowing?

 

Well, yes. You need to have an idea of what's going in the bed or tongue weight of trailer ahead of time. Not necessarily "if it fits it ships".
D range tires squatting at max pressure is a good sign to stop on a 1/2 ton.

Use some common sense when loading and it will likely be fine.

 

Yes