I have s 2004 f250 4x4 crew super duty 6.0 Psd auto just put in new long block. Has a strong vibration between about 50-60mph only in overdrive with little acceleration , and gets stronger as I acceleratea little more , until it shifts out of overdrive or let off the accelerator or over 60mph and then it goes away completely. I have checked ujoints and replaced drivshaft center hanger bearing , rotated driveshaft 180 , maybe motor mounts ? In need of help please...

 

Have you tried shimming your carrier bearing so that the front and back drive shafts are in a straight line?
If you or someone else replaced the U-joints in the drive shaft, there's a possibility of getting them slightly mis-aligned. This will create a vibration like you describe.

If you get the U-joints installed perfectly centered, this will minimize the vibration regardless of whether the shafts are in line. Shimming the carrier bearing reduces the affect of a mis-alignment of the shaft in the U-joint if there is any.

 

How about some more info to go on? Is this truck lifted? What size tires? Did it do this before the long block swap?

Honestly it sounds more like sticky injectors to me, or is it very rhythmic, like an out of balance wheel? Where do you feel this? In your butt through the seat? Through the pedals? Through the steering wheel?

 

Thanks for the responses I tried shimming the bearing but that didn't help and the vibration much definitely comes through the steering wheel. The truck isn't lifted and has almost new lt285/75 all terrain tires to my knowledge the truck did not have the vibrating prior to the new engine. I also and the tow haul and cruise control not working checked fuses the indicator lights dot come on maybe I missed a connection or vacuum I think that its probably related. I wish I could get this truck on the road soonko

 

do you have a scanner to check for injector codes??

mine is currently doing that, along with rough idle... #2 injector code. so i would lean to a injector/FICM issue

 

I had the same problem recently. In the final gear between roughly 1200-2000 rpms it would cause the whole truck to shake. as i gave more acceleration it got more rapid until i broke about 70 mph. if i gave enough throttle to downshift and take off from 45-60 mph it went away. only happened in final gear. mine turned out to be injector 7 so i would definitly say that if it has these types of symptoms its a injector for sure. replaced it myself. took about 3 1/2 hours for me to do on my own and it just so happened to be the passenger side in the very back. .

 

mine turned out to be a loose connection on my FICM, so deffinetly check those connections

 

Well mdub got it bing! Right off the git go. #6 injector and a bad ficm harness wahoo on the road and running good thanks. For the great advise guys keep the bugs off thegit glass and the bears off your a$$. Im gone.