Ok so here's the problem I've came across. Recently I was driving to arkansas and was about to jump into the passing lane to pass up a few semi trucks. All of a sudden I get a vibration from what feels like under my truck. It does NOT do this every time. It's occasional. Truck will run perfect for a few days and then during a drive when I begin to pass a car I feel it again. My check engine light came on and said I was misfiring on 2. So I changed the plugs and coil out. Reset the code and before I could get out of my driveway it came on again. Misfire on 2. Then it went off for a few days. No problems until i felt the vibration. This time it made my truck seem like it was choking when I came to a stop. Just like it does when you have a misfire. So I swapped the coil packs and plugs around. Moved the new set to 6 and took the set off 6 and installed it on 2. Just to see if it was the spark plugs or coil. Still misfiring on 2. Then the light will go off again. No vibration, no nothing. Cpl days go by, I start to pick up speed on the hwy and guess what, vibration. It's starts off light but the more I press the gas the harder the vibration is. I will down shift my truck to a passing gear and then slap it back up a little at a time. Vibration gone. WTH could this be?!!! MDS failing? U JOINTS? Drive shaft itself? Losing compression on 2 and then getting it back all of a sudden for a few days? I know I need to replace my ball joints. Bit that couldn't be the problem, could it? When I first seen the light come on, I replaced all plugs and coils. The original coils were still on and I couldn't tell you when the plugs were changed since I've only had the truck for a few months. When I purchased it, it had 104,000 on it. Oh, and I've also had my service 4x4 light come on 2 twice since I bought it and it also went away. Someone told me that a lot of 4x4's had a faulty sensor that would set it off for no reason. But, the first time it went off it felt like I was about to slide into the walmart building. Steering was shady. Now before i forget, i cam drive for a few 100 miles straight before i feel any vibration. It usually comes out of nowhere when i start to pass someone and it downshifts. Any recommendations would be grateful.

2012 ram 1500 5.7 4x4 crew cab

 

did you check the transmission fluid ?