I have a 99 dodge ram 1500 when I get it to 40-55 mph the engine starts ticking and the truck begins to shake, but if I get off the gas the tick stop and the truck stop shaking. Can anyone tell me why my truck does this?

 

Sounds like a miss. At approximately 45 MPH, the truck wants to shift to overdrive, and engage Torque converter clutch. If you have a miss, it will show up VERY well right at that speed.

How do your plugs, and the rest of your ignition parts look?

Welcome to DF.

 

I had the same exact problem on my '01 Ram. CEL on, code reader showed number 8 cylinder miss firing. There was a tiny crack on the plug, replaced with new copper plug, works great.