Hi All,
I've poked around here a little and didnt really see anything specific to the issue that I'm having. My '05 F350 PSD has developed a pretty bad vibration most noticeable above 40mph but only under acceleration. As soon as i hit speed and let off the gas its gone but if i accelerate again to pick up the speed i lost its back. Haven't looked into it too much yet as i was busy all weekend and drove the Expy but I did get down there and dont have an obviously bad u-joint or carrier bearing. Anyone have the same symptoms and what fixed it? I'm also gonna see if i popped off a driveline weight or something. Thanks in advance!

-Torsten

 

Even though you say you don't have an "obviously bad" u-joint, that's where my money is. Pull the shaft to find out for certain, that's where I'd start. Being at higher speeds and only under acceleration is a pretty good indicator of a u-joint.

 

Got it fixed up tonight. Yea, when i picked up the rear end and put it in neutral to take the tension off the driveline the back U-joint was definately toast. Luckily easy fix. Thanks!

-Torsten

 

Hello,

I have a 1998 expedition 4x4 that vibrates during acceleration. The vibration used to go away when I reach 60 MPH. Now it goes away above 65 MPH. I checked the u-joints and it does not seem like they have play. I lilfted the rear wheels off of the ground and I can take the rear driveshaft and move it up and down where it comes out of the transfer case. Could the splines on the rear driveshafts be worn out enough to cause the vibration or is it an internal transfer case problem? Thanks for you response.

 

so my 01 F350 PSD is having a similar issue, I have checked the flexplate and it looks fine. i wish i knew what the deal was because when the truck is not moving and stopped at a stoplight for example, there is noticeable vibration present. could it be the torque converter and if so how would I tell because it shifts fine.

 

Bad U joint or joints, out of balance tires or worn tires or a loose exhaust. Any mods done to the truck?

 

The vibration is there even when i am stopped at a light. There was a wierd ticking noise that is no longer when i used to put it in park.

 

Could it be a broken engine mount? The vibration from the engine at standstill might be rumbling through the truck?

 

I looked at the mounts also and they are fine. Sill did not explain the ticking or clicking sound when I placed it in park. I am kinda suspecting the T/C but this it going to be a tuff call. I guess I will just have to see what the mechanic comes up with and I am hopeful that he gets it right the first time $$$$.