Hey guys, im gettin a serious vibration at 65 and up especially if i let off the gas and coast...rattles the whole truck...U-joints?? or any ideas on what else to look for....2000 5.4 4r70 trans, lotsa lotsa miles but still runs great except for this problem lol

 

mine is doing the same thing at speeds above 45mph they told me since i have 8 inches of lift it is a ujoint on driveshaft and i need a driveshaft spacer....do u have a lift?

 

Friction Modifier Breakdown. Very common, this will shake the entire vehicle, allot ! - Gives the impression that your vehicle is coming un glued lol.

The Fix. - Change the rear fluid with recommended synthetic and add 8 oz's of friction modifier, -per recommendation. Basic service.

Vibration will go away completely within 75 miles from change out.

Good Luck.

 

thanks jbrew...was thinking that as well...will change fluid out this weekend and post up results...may do the u joints also but know they are a PITA...lol

no lift on the truck mote88

 

Id change the U joints!!

 

I have had u-joints cause a vibration on my old 94F1504x4SWB. New joints in the rear drive shaft cured it.