Topic: U-joint replaced.......vibration

[spacoli]

I had a vibration only around 25 mph and when I had a load in the truck, I had no vibration. So I thought it had to be the older u-joint (replace one already two years ago).

I had the truck in for inspection and had the shop change the u-joint. It fixed the vibration at 25 mph, but now I have the faint vibration at higher speeds that I didn't have before. The vibration is typical rythmic sound that you hear when a u-joint is going bad.

Any thoughts or ideas what might be causing this? Bad u-joint, bad instalation? Thanks

[79coyotefrg]

I had a vibration only around 25 mph and when I had a load in the truck, I had no vibration. So I thought it had to be the older u-joint (replace one already two years ago).

.............. but now I have the faint vibration at higher speeds that I didn't have before. The vibration is typical rythmic sound that you hear when a u-joint is going bad.

Any thoughts or ideas what might be causing this? Bad u-joint, bad instalation? Thanks

probably the joint you replaced 2 years ago

[BLACKDOG]

probably the joint you replaced 2 years ago

how true it is, but I've always been told to replace both joints at once.  If one is going out, and you put a new one in, any stress is amplified to the older one, because it is more worn, and it kills it that much quicker, so its a vicious circle of swapping them out.  If you replace them at the same time, they deteriorate equally, and together last longer. 

[jimbo74]

did the place jsut take the old one out and replace it? is it possible they made the shaft out of sync? have you had the driveshaft balanced?

[Hyena]

or they didn't align the joints when they put the driveline back together (splines, ears)

[jimbo74]

or they didn't align the joints when they put the driveline back together (splines, ears)

yeah thats what i meant when i said its possible they made it out of sync

[Hyena]

yeah thats what i meant when i said its possible they made it out of sync

 thats what i thought, just cleared it up a bit. 

[jimbo74]

thats what i thought, just cleared it up a bit. 

yup thanks for clarifying that.... haha, i re-read it after you posted and was like.... hmmmm maybe he didn't get what i was saying, haha, i barely got it, and i said it

[spacoli [OP]]

I'm guessing there must be some allignment markings??  I will have to check it out.

As for the older u-joint being bad, I had no vibration at higher speed at all before, so I ruled out the other u-joint.

thanks

[spacoli [OP]]

Yep, there was a white mark on the shaft and it was not lined up with the white mark on the yoke, I will have to un-bolt and line up.

The marks are almost 180* off.

Hopefully that is the problem.

[Hyena]

i don't know of any marks on the shaft.  but the joints must be lined up, the ears of the shaft should look kinda like this   ]=====[  with each other.

[spacoli [OP]]

I'm not sure, I know there are white paint marks on mine. I will check out my ears.

[BLACKDOG]

I'm not sure, I know there are white paint marks on mine. I will check out my ears.

It was prolly marked before the shop took it apart.  Of course, some people aren't smart enough to actually use the marks to put them back together.  Like Hyena said, as long as the ears are lined up, it doesn't really matter where the marks are.

[Monster Yota]

This doesn't necessarily sound like your problem, but possibly the splines in on the driveline are a little worn, now the yoke has a little bit of play over the spines, this will cause vibration. On mine if I have the gas on it is perfectly smooth but if I let off to coast the yoke will start vibrating... which translates through the floor board, to the seats, to your behind, and the steering wheel....     Its a simple fix, just need to find a good tight spline set, maby off a newer truck with low miles,,,, possibly off the front drive shaft since it would have less wear...   

[spacoli [OP]]

Just an update, I lined up the white marks, which lined up the "ears" and the slight vibration is gone. Thanks to all for all the input.