Video of Driveshaft - Bent or bad U joint?

[jmrwd3]

Hi all, I've been having a bad vibration starting at 35, I finally jacked up the back of the truck and sat it down on a stone retaining wall to see if I could get the vibration to occur without actually driving. I did - most noticably in 1st and 5th gears. This video is very hard to see, but you can see the transfer case shaking around, the drive shaft looked like it was shaking too. Near the rear differential there was no noticable vibration. The dealer told me the driveshaft is bent, I could find no damage or nicks, or even the bend they are speaking of. Firestone thought it was the u joints, and even took the entire driveshaft to an independent shop who said it all looked fine.


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[Victor]

Undo the driveshaft at the companion flange (4 nuts and bolts. Move the U joint in all it's directions make sure it moves smoothly with NO binding whatsoever. Do that to all of them and make sure they aren't sticky or binding. Remember to mark where you driveshaft was with a paint pen BEFORE you remove it to make sure it doesn't go out of phase.

 

[jmrwd3]

Can I drive in 4 Hi Front wheel drive by removing the rear driveshaft and not damaging the truck??

The U joints definetely need to be replaced, I am going to have a transmission shop rebuild the driveshaft and balance it before re-installing it

 

[Victor]

Just drive it normally in 2WD and take it to the shop, I hope it's not a far venture but either way the u joints if thats the case are toast.

 

[shawnstcyr]

Can I drive in 4 Hi Front wheel drive by removing the rear driveshaft and not damaging the truck??

The U joints definetely need to be replaced, I am going to have a transmission shop rebuild the driveshaft and balance it before re-installing it

Although I don't see why you'd want to, you could. The yoke coming from the transmission is held onto the output shaft by a lock nut. This could be a life saver if you ever bend a shaft on a rock way out there on some trail. Or break a u-joint.

 

[shawnstcyr]

BTW, you did have the rear diff supported correct? If you didn't you changed the angle that the shaft would normally operate at.

 

[jmrwd3]

yes I had the rear driveshaft supported, not sure if it was at the exact level it would normally be but it was close. I am having the driveshaft rebuilt, hopefully that will help.