What's the signs of a failing u-joint?

My daily has a horrible vibration at anything above about 40MPH. I kinda think it's the joint because I can feel the shimmy in the seat. I've rotated the tires and it still shook like a fat lady on a washing machine. I'm stumped.

 

you have bad tire, u-joints will start vibrating at much lower speed, run your hand over the tread surface of each tire, the one with loose belts will have a knot or lump in it

 

well if you cant feel any play in the joint then look for a rusty color around the joint or if u have time take the drive shaft off and move the jont by hand to feel roughness or binding

 

I usually can tell around 2nd gear and I see the driveshaft cartwheeling down the road in my mirror.

 

Bad ujoints usually tell you they are bad before they get REALLY bad.

Typically there is a "ching" noise as it is shifted from park to drive, or park to reverse.
If it does this for a long time, it will vibrate horribly. Then it will fly apart.
Sometimes the tailshaft bushing in the trans is bad, and that feels like a u joint. Broken trans mount and bad tires cause vibrations as well.

Best to jack it up and check it all.

 

i know mine are bad when i hear a slapping sound against the bottom of the car and sparks

 

Ask Tammy 'bout this in her Olds!!!

I'll check all that this weekend when I'm trying to keep all my other junk running

 

sometimes U-joints that have become dry will make a squeaking noise when you back up -

"flamers and gamers and AOL lamers" need not apply

dj

 

Did it come on gradual or all of a sudden? Generally a seized u joint will vibrate more on harder acceleration and harder stopping.A worn joint will make a loud clank shifting from forward to reverse and vice versa.Driveshaft angles are extremely important for u joint life expectancy.

 

a klunk. metal on metal chinking noise. free play if you move the driveshaft by hand is the easiest way to check. also low speed vibrations are usually a sign of them starting to go bad.

 

squeeking ,squealing, thumping, vibration, (vibration could also be an out of balance drive shaft it it threw a counter weight) you'll have to crawl under there with the rig in neutral so you can wiggle the driveshaft to see if its sloppy,

 

Food for thought! if you drive an auto trans. it could be your flex plate (fly-wheel) to tork converter bolts. Had a new truck out of the box like this. If it's not your "U" joints, pull the dust cover and check it out.

 

I had the same thing on my 53 Buick and it turned out to be the right rear tire had a bubble in the inside sidewall of the tire. I sent it back to Dimondback and they replaced it, problem solved. Rags

 

Ya know, I did have the 4l60e rebuilt 'bout 5k ago. I may take it back and have them check it out.

 

I have problems with U-joints on "Fred" my daily 89 Chevy half ton. It has alot to do with the quality of the aftermarket joints, and the fact that it is so hard to get grease to all 4 corners of the U-joint. I usually have a set of roller bearings turn to dust and they'll create an annoying as hell squeek, as well as allow the shaft to jump around in the holes (sounds kind of kinky, don't it?).

Another way to tell if you've got U-joint issues that are causing your vibration, jack up the rear of the truck and place it on jack stands. Next, take another stand and raise it up next to the driveshaft. I'd place it where it is just a hair away from the driveshaft and next to a U-joint, and then rotate (or have someone else do it) the wheels (to turn the shaft) so you can see if the joints are showing as being 'out of round'.

I've also had issues with those damned POS needle bearings before with just a single one laying down across the center of the inside of just one cap. This allowed the joint to fit the yoke just enough off center to create a helluva vibration. This too could have been caused when the tranny was done.

 

The ass end of my Ford duelly jumping up about 2 foot while it pole-valted over the drive shaft gave me a clue!

 

i have had only one go complety out in my 25 years of shit building. and it was sudden and complete destruction. it pole vaulted my 72 torino about 50 yards (came out at the front) i thought i was going endo. fast, fast , fast, shake, shake, shake, OH SHIT!!!

 

if ya take yer ride fer a drive fer a few miles, head back ta da shop n jak'er up, put'er on blocks/stands, n slide under and feel them joints...if'n ya got a dry one er a tite one, it'll be warm or HOT, so be careful as ya don't wanna git burnt. Ya dit'nt say, but if yer daily has a 2 peace driveshaft with a center support bearin, that bearin could be goin bad as well.....and yep dat could mak'er shake like a washin machine with da fat lady IN it!!!

 

sounds like a boy sneekin a peek at pa's porn stash....n makin a mess on one da pages!!!

 

It's that crunch crunch sound