Hello everyone, new to the forum and hope someone can help, I have a 2004 f150 supercrew with a 5.4 2wd 58000 miles the truck has a very fast vibration at 15 to 30 mph, tires trued and balanced, no vibration up to 15 or after 30 TKS Gunshot

 

Where are you detecting this vibration? Through the floor,steering wheel,something starting to rattle?

How do the tires look, are they cupped?
Have you checked the u-joints or carrier bearing?
God forbid, are all the lug nuts tight?
Have you tried to bring the RPM's up while in park or neutral to see if it does it?
Checked the motor and trans mounts?

Could be just about anything. Maybe a tad more explaination would help.

 

Sounds like a misfire..

 

TKS for the reply, the vibration is mainly in the steerins wleel but you can feel in the floor also, I can feel it between 15 and 30 going up and coming down in speed, brand n
new tires trued and balanced, it feels like it only does it in second gear. hope this helps. the truck has 58000 miles

 

After testing your truck to make sure it is safe to drive, jacked it up and spun the wheels, tested for loose steering linkage, shook the drive shaft to make sure it isn't loose or binding due to dry bearings, you may have to wait and see for a short time. The vibrations should continue to become worse. A friend of mine had one and couldn't figure it out until he threw a blade off the fan thru the hood. He had removed the shroud looking for the problem. Hope you don't have a similar loose idler/bearing or bad belt. LOL

 

Shaking the driveshaft will only show a ujoint that is about to fall off. The right way to check the ujoints is to remove the driveshaft and check for bound or loose ujoints.

 

If it is a cracked torque convertor mounting it will come off soon, or a nasty leak will develope. Also check the front of your crankshaft. The sucker may be coming off. A motor coming out of ballance can develope some real weird vibration characteristics. Shake go smooth/shake again when the RPM's double that point.

 

TKS, everyone for the input, I found the problem. the drive shaft was out of balance, no weights, dont know wrere they went but gone, agin TKS .

 

i have a 2002 4.2L with the same problem could it be the same thing or were transmissions different in those two trucks?