'05 F250 Super Duty shudder on take-off

[LIQUID FIRE]

I just test drove a 2005 F250 with the 6.0 Turbo Diesel and it seems to run great.

The only concerns I have are that on take-off there is a shudder and when cruising at 55-60 mph and then letting off the throttle completely there is a bit of a shudder/harmonic vibration that can be heard and felt through the floor board. It has 4" straight exhaust pipe and is lifted quite high.

I was told by a Ford diesel tech it was the exhasut I was feeling but I was wondering if the cause could be in the way it was lifted?

Has anyone run in to this before?

[rem1981]

Pinion angle perhaps?

[LIQUID FIRE]

I was thinking that may be the problem. How about the shudder/harmonic vibration at 55-60 mph. Think that may be the same thing?

[rem1981]

It's a good possibility. I hope someone else chimes in with some suggestions. How high of a lift are we talking? The vibration at speed could be anything from wheel balance to maybe even driveshaft balance. Hard to say for sure...

[rem1981]

Oh, and I also have 4" straight exhaust, and it certainly does not do that. I wonder how the bearings in the differential are. That could do it.

[Dante04SRT]

My F350 does that, too. Upon initial acceleration from a stop, you can feel a slight shudder. At highway speeds, you can feel it and hear a droning sound.

On my truck, it's definitely the driveshaft out of balance. This is most likely the case on this truck as well.

[Galaxie]

I would nevery buy a problem. Unless its a truck for 10k, stay away.

You can buy a good clean one, lift it and put exhaust on it. Never buy a problem unless you are into restoring old cars. lol

[LIQUID FIRE]

Here is a picture of it to get an idea of the lift. Someone also mentioned it could be the turbo. The noise/vibration is not constant. I can feel it for about one and a half seconds when the RPM's are dropping.

[Acidsniper]

Well there's many things that could be causing that, the turbo doesn't sound like it'd be the culprit as the straight pipe exhaust would eliminate a backpressure blockage that could cause turbo surge or burping.

My initial thoughts:
Driveshaft imbalance
Carrier bearing / ujoints shot (crawl under the truck and jerk the driveshaft around, is there excessive vertical and / or horizontal play in it)
Wheel aligment / balance (you'd be surprised what a bad balance can do)
Pinion angle on the lift (can't see that pic as photobucket is blocked by our company firewalls)

Are you getting any check engine lights / codes?

[LIQUID FIRE]

No check engine lights. It does have an Edge programmer, but I dont think it will keep the MIL from coming on. I can feel that the rear tires are out of balance slightly, but I feel that my concern is coming from the drive line. I will check the carrier bearing and the ujoints when I get a break.