I have an '06 250 c/c fx4. It has 7323 miles on it and when I pull my trailer at work I get a vibration at take off. If I baby it, it doesn't do it and it only seems to do it when pulling a trailer. I thought it might be the torque converter but it only does it in first and second gear no other gears. Should I get this checked out

 

My guess is the carrier bearing on the driveshaft, though it could be a broken/loose transmission mount. You may also want to lube the splines on the driveshaft slip yoke.

 

you also might want to check pinion angle

 

My 06' F-350 6.0,SC, short-bed, does the same thing, no carrier bearing on this truck, pinion angel looks straight with driveshaft, if I take-off easy hardly noticeable,,launch harder,,feel it shudder, have a trailer en-tow,,feel it more, goes away about 15 mph !

I took off from a stop last night,,,put the tranny in 2nd (TS auto tranny) seemed to still feel the shudder,,the truck turned 12k yesterday, this shudder is the only small issue I would like to figuer out,,other then that,,the truck has been excellent !

 

I've had several RWD cars that have developed this when lowered and my truck did it every time I (over) loaded it up for a move. I've heard it's caused by the change in relationship (angle) between the centerline of the transmission shaft and the pinion shaft of the rear end. In other words the rear u-joint can look straight with the driveshaft, the issue may in the relationship between both ends.

Jeeps run into the same issue when lifted, the cure is CV joint driveshafts. The misaligned trans&pinion causes the driveshaft to accelerate and decelerate rapidly causing the vibration. My issues were the same, just caused by the changed in angles resulting from lowering/load.

The cure for the lowered cars was adjustable upper torque rods, since the truck only does it with a major load I don't worry about it. For trucks doing it with no load, I strongly suspect BowTieHatr is right on the money, as usual.

 

This was issued for 'single driveshaft' Super Dutys and may help you out:

Shudder on Acceleration:
On trucks with single driveshafts, check the rear axle spacers. If the spacers are installed with the thin side (1 7/8") facing forward, they should be reversed (swapped left to right) so the wide side (2 1/4") faces forward. If the truck now only shudders with a load, swap out the spacers with 2" flat ones from an F250 long wheel base (two-piece driveshaft), P/N 2C3Z-5598-PA.

 

My crew cab short box has a two piece driveshaft (I think). Is there a TSB relating to the shudder issue and the carrier bearing position? Seems like I remember something about shims for the bearing.

 

kb,

This is for older trucks but it may still work with yours:

99-03 Super Duty F-Series Two-Piece Driveshaft Shudder:
Some trucks may exhibit a vibration on moderate to heavy acceleration from a stop. This is usually due to too high of an angle through the center u-joint. The correct angle through the u-joint should be 0.5-3.0 degrees (compare front shaft angle to rear shaft). Check the engineering number of the center bearing bracket to ensure it is the correct application, and replace if necessary. If the bracket is correct, the shudder may be corrected by shimming the bearing down from the bracket using up to three 1/4" shims, part number E0TZ-4A209-A and two grade eight bolts long enough to expose three threads above the nut when tightened to 46 ft/lbs. Loctite is recommended. Broadcast Message 0518, 1475; TSB 04-22-7, 05-17-6.

 

I was told by the diesel mechanic that this is nothing more than axle wrap. The spring rate on the rear axle was sofented to improve ride quality but as a result made it more likely to experience axle wrap. Shims will stop this but the mechanic told me I might experiece some noise or vibration at high speed if I did this. This guy is supposedly one of the best ford diesel mechanics in the state of North Carolina.

 

You know,,I almost think it is related to a softer spring,,sounds about right,,plus I seem to get this slight bouncy ride now and then,,,hmmmmm,,guess I need to do some experimenting,like load truck more,,and or unload what I have in it !

 

Thanks for all the input. I will look into these issues

 

I had the problem of shuddering when I was pulling my 12,000 lb 5th wheel. My truck is an 06 F350 crew cab/dually. I've added load leveling air bags to my rig and have eliminated the problem. The truck would squat to the overload springs which is, apparently, enough to cause the problem.

 

does your truck have a rear sway bar or aftermarket exhaust. the sway bar bushing could be shot . or the exhaust could be hitting something.??

 

My truck has 10,000 miles and is bone stock. It appears that it was just a matter of the truck squatting too much with the load of the 5th wheel.

 

My 06 F250 only does it when i have the bed loaded down with 500-800 lbs and my 22 ft travel trailer in tow.It seems to do it right before it down shifts also,It is like your tires are running on the side of the road in the vibration grooves,until it down shifts and then it goes away.The dealer wants me to load it up and go for a drive to check angles.