I drove to work one morning last week and everything was running fine. 4 hours later I get in to go get some lunch and as I'm backing out I feel a small thud or shake and that was it, I put it in drive thinking it was a hiccup and started on my way. It was not constant at first but as I get down the road every 10-15 sec it would shake for a period of time, sometimes violently but for the most not that bad. It seems to be more violent when I'm accelerating at low RPMS. If I'm just cruising (foot off the pedal) it seems to stop. The weird thing is sometimes I'll be going down the road and it will stop for a period of time and my truck runs normal, but then will start back up without notice. I was on empty that morning and got a quarter tank from a random station, thinking it could be the gas I gave her some seafoam and filled her up, no luck there. My knowledge tells me to replace the plugs/wires/cap. Anything else I should check before I spend the money? Thanks for any info.

​​​​P.S. My power steering was bone dry about 2 days before. Filled it up and worked fine. Just in case someone has had a related problem.

 

What are you driving? What motor?

 

Sorry, 2000 Ram 1500 WS 3.9L magnum

 

Does it get worse right about 45 mph, when it shifts into O/D?

 

has anyone been able to help this issue ? I’ve got a 98 ram 1500 5.2 L and it does the exact same thing so I’m hoping to gain some knowledge from you fine mechanics out there .
thanks a lot guys for everything!

 

How old are ones in there? If you replace the cap get the "oem style" it will have brass inserts. If not they will give the cheap cap with the aluminum inserts that will corrode in no time.

 

Yes it seems to be worst after it shifts around 50 mph and that was at a steady acceleration. My tachometer was jumping/floating around 100 rpm of where it was at also.

 

That's a miss. Did this problem start before the tune-up? Or is this something that came up later?