1996 ram 1500 5.9L 26gal tank---had to replace fuel pump--ordered online to save $$--pump came with sheet listing several wiring combinations in case wiring did not match--pump has 4 leads--truck harness has 6 leads--none of wire colors on sheet match actual wire colors on truck…
Engine shakes in idle (park, neutral, drive) and at speed. No real loss of power, and it does not seem to change with speed. Plugs and wires were changed by a mechanic about 6 months before this started. The truck has 240k miles on it, so I suspect it may be an engine or transmission mount, but before I start inspecting it (I have to put it in a location I cannot keep there for long) I want to run through all possibilities. Thank you.
Could still be an engine misfire or the mounts as you suggested. If it was a consistent misfire, it set a code and illuminate the check engine light on the dashboard. If there is a higher than normal idle along with it, don’t rule out a vacuum leak. Since it happens at idle in park that rules out quite a bit. I think you are on the right track.