This is directed to anyone who tows any heavy loads. My 2008 6.4 L Super Duty 4X4 (9300 miles) has this out of balance vibration in the drive train when accelerating with my 11,000# 5th wheel camper attached. It only happens under hard acceleration 1000 to 2800 rpm like starting from 5 mph up the 2% grade on my street. It will vibrate from stop on level ground but not as bad. The vibration is bad enough to make things in the door pockets rattle. I'm not sure if it's in the engine, transmission or driveshaft assemblies. It doesn't vibrate at all when I'm not towing and runs and feels fine at highway speeds even with the 5th wheel camper. I am taking it in for the venturi and fuel tank recalls this Monday AM and I will report this but I know without the camper attached the tech will never be able to replicate the problem. Has anyone had this problem and do any of the techs out here have any idea what it could be?
Thanks in advance

 

It is caused by the drivshaft alignment. When you have the weight of the 5th wheel in the bed it changes the alignment. Your dealer should be able to shim the drive shaft to alleviate the problem.

 

yes mine does that but not near as bad as you describe. There is some question if he shim fix works.

 

drive shaft alignment is the issue. Mine did one time, discovered the dealer only put minimal air in the tires and that cured the problem.

 

Welcome to FTE

As stang stated they can shim it to fix the problem. The only thing is that some people end up moinvg the problem to only when the truck is unloaded. You should feel the shutter only when you take off from a stop. Ive had the same issues now for 30,000+ miles.

 

It really had me kind of worried since my truck has the infamous engine rattle when it gets warm. Thanks Again

 

Here is the TSB from ford on this issue


<TABLE cellSpacing=0 cellPadding=3 width="96%" border=3><TBODY><TR><TD class=VERTCENT align=middle width="25%" bg***************>TSB
08-24-6
</TD><TD class=VERTCENT align=left width="65%" bg***************>

• SINGLE REAR WHEEL (SRW) - SHUDDER OR VIBRATION ON ACCELERATION (ESPECIALLY WHEN LOADED)

</TD></TR><TR><TD bgColor=#0000ff colSpan=2>[************]Publication Date: November 21, 2008[/COLOR]</TD></TR></TBODY></TABLE>
<TABLE border=0><TBODY><TR><TD width=230>FORD:
</TD><TD>2008-2009 F-250, F-350</TD></TR></TBODY></TABLE>

ISSUE:


Some 2008-2009 F-Super Duty 250/350 vehicles with Single Rear Wheels (SRW) may exhibit an excessive drive-away shudder or vibration under moderate to heavy acceleration from a stop, especially when heavily loaded. This may be due to driveline angle. The shudder or vibration may be more evident while towing a trailer or if vehicle is over loaded.

• Trailer tongue weight should be 10-20 percent of the total trailer weight, depending on the hitch.
• If towing a 5th wheel trailer or gooseneck trailer the centerline of the hitch should be two (2) inches in front of the rear axle centerline.
• Refer to the Owners Guide and Certification Label on the drivers door for maximum payload and cargo capacity.

ACTION:

Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE



<TABLE border=0><TBODY><TR><TD width=80>NOTE:</TD><TD>TECHNICIAN SHOULD DISCUSS WITH THE CUSTOMER HOW THE VEHICLE IS DRIVEN THE MAJORITY OF TIME (LOADED OR UNLOADED), AS ADJUSTING THE DRIVELINE ANGLE PER THIS PROCEDURE MAY RESULT IN A SLIGHT SHUDDER WITH VEHICLE UNLOADED.</TD></TR></TBODY></TABLE>
Due to changes in the suspension, the repair procedure is different from prior model years (1999-2007 F-Super Duty). Using the worksheet to measure and calculate the three working angles. Then using the working angles calculate the operating angle. The driveshaft should have an optimum three (3) degree operating angle. If necessary, change the pinion angle to the axle and the height of the center bearing (CB) carrier bracket.

 

I'm glad to know it's nothing serious. I drive it most of the time unloaded so I think I will leave well enough alone.