QuestionQUESTION: 2002 F150 SuperCab. 93,000 miles. no mods. 4.6l,Rear wheel drive.
Developed a vibration that is felt in the seat. It is between 38 and 42 mph.
Again felt above 65mph. Seems rotational. Steering is solid. Rotated tires
front to rear no change. Even bought new BFG Long Trail Tour. Drive shaft
balanced and new u-joints. No change. New rotors and brakes front and rear.
Even disengaged emergency brake. No change from rear vibration. Vibration
is speed dependent. Vibration in gear or when coasting in neutral. Even put in
neutral and shut off engine, vibration continues. Question is could this be an
extension housing bushing, I have a slight leak from the rear transmission,
fluid doesn't drop to ground but is slung onto bottom of cab. Does the
driveshaft turn when the truck is in neutral and the engine off? Truck has
never been wrecked. Local Ford dealer wants $300.00 for estimate.
Tires Road Force Balanced one week ago.
Thanks,
John
ANSWER: When you had your tires balance did you have them ROAD FORCE MEASUREMENT done if not this could be the problem 1997-2002 E SERIES, EXPEDITION, EXPLORER, F-150, RANGER, WINDSTAR The purpose of this bulletin is to provide guidance when using tire/wheel assembly road force measurement equipment such as the Hunter GSP97OO. This bulletin is authored and endorsed by Hunter, Michelin, Goodyear, Continental/General, Hankook, Bridgestone/Firestone and Pirelli. Items addressed are software upgrades, road test (exercise tires), assembly center verification .This is a ford TSB.ACTION
The Hunter GSP9700/9712 road force measurement tool is NOT to be used for determining if a tire or wheel meets a specification. It can be used as a service diagnostic tool to minimize road force variation of the tire/wheel assembly. The tool such as the Hunter GSP97OO can approximate the low point of the "'1heel and the high point of the tire. This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly road force variation. This will minimize the contribution to vibration from the tire/wheel assembly.
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QUESTION: After talking to the local Ford dealer, I was reassured that they were using the latest Hunter machine. I have a brother that has a similar Ford truck. I plan to swap tires and see if there is any change this week-end. What else would cause besides tires? As I stated I have rotated tires front to rear with no change to vibration.
Thanks for your time.
ANSWER: The way to see if it is in the Trans while driving at your vibration speed disengage the over drive button and see if it changes if it does you may have a converter or a flywheel problem.
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QUESTION: With the overdrive off the vibration continues. I am curious about the "jump
rope" effect of the long aluminum driveshafts. Have you heard of this, even
though I have had the shaft balanced? Wouldn't this situation be re-created
on the balancing machine?
Again Thanks,
John
Answerwhen they balance a drive shaft they usably do a run out to you need to see if this was done and did they remove the drive shaft to balance it or did they do it in the vehicle .You have to remove the complete shaft to balance it properly and is this a single shaft or a split shift.
