A few months ago I asked for help in solving my vibration problem in my Cummins 04 duallie. Received a lot of good imput and as you may remember, I had the 48re trans gone through, had a new flex plate and converter and every u-joint replaced on the truck and I still had a vibration from 58mph to about 70 mph.
Well boys and girls, I listened to an old friend, Ed Eckenrode who told me it was in the motor, which I might add, was a new re-man Cummins! Well Ed was correct, it was a bad injector which only had 20,000 miles on it. It was partially plugged, so it appeared that the electrical tip was cracked and was not fully working! Finally the vibration was gone, what a relief. Thanks for all your help. HEMI JOE