Bad Vibration

[Daddy's Big Truck]

Recently noticed I have a bad vibration from underneath. Only on acceleration and around 2K RPMs and higher. If I let from the throttle, it quits, so out of balanced tires is ruled out. Anybody got any possible causes. Just had ball joint replaced and mechanic told me it appears the U Joints are loose. Could this be the problem? Or am I looking at something more serious, like a bad torque converter.

 

[Bronc76]

May want to check to see if wheel bearings, u-joints, or any suspension component is loose or worn. Driveshaft out-of-balance?

 

[AdamDude04]

Easy check.. Grease the driveshaft slip yoke. Cheap an easy to rule out.

Doing mine fixed my issue

 

[miesk5]

yo,

Since the mechanic mentioned u joints;

Troubleshooting, "...chock the wheels, put it in neutral, and grab the driveshaft and twist it back and forth. examine the u-joint area for any excessive movement..."

Miesk5 note; Spicer says, "...To cancel an angle vibration, the universal joint operating angles need to be EQUAL within 1 degree at each end of a driveshaft..."

Source: by memphisrain & me

Vibrations, General; Improperly phased or twisted propshafts; "...A twisted or improperly manufactured propshaft can have U-joints which are out of phase. This causes improper U-joint acceleration and deceleration cancellation to take place. The result is a second order propshaft speed related vibration. To check U-joint phasing, perform the following steps.." read more & scroll through the sub-topics Source: by vibratesoftware.com

Tire Speed Related Vibrations; "...As the axle shaft rotates, the U-joints actually speed up and slow down twice per revolution, this is not a constant velocity device. A U-joint which is failing can cause these speed fluctuations to be felt or heard by the driver of the vehicle. This type of vibration will typically be worse when turning corners. Most vehicles will not have the U-Joints rotating on solid front axles unless the hubs (if equipped) are locked..."

Operating Angles, general; "...When you rework a chassis or install a new driveshaft in a vehicle, make sure that you follow the basic rules that apply to universal.." read more Source: by 2.dana.com

PTFE Lubricant; For use with: driveshaft slip yokes; especially where grunt-type noise is experienced; eliminating squeaks between plastic parts; speedometer cables; stops squeaking, sticking & binding Source: by fcsdchemicalsandlubricants.com