notice it on deceleration only. probably there on acceleration but cant notice it. A vibration that i can feel in my feet, new ball joints, not a slow vibration, more of a high frequency deal. Any idea where to start at? I know this is vague, hard to describe. thanks!!!

 

Sounds like a bad u-joint.

 

Didn't think about that one. What is the best way to check them?

 

With the truck in neutral, grab, tug, pull on, and twist the driveshaft by hand. Look for ANY movement in the u-joint cups and seals. They should be rock solid with ZERO movement if they're good. Sometimes they are hard to tell unless you know what to look for but if you're experiencing a vibration on deceleration then I'm really leaning toward one or more u-joints being bad.

 

you can also have one tighten up so that is not a good check. I would remove the drive shaft and also check for one that has gotten tight. another tell tell sign is rust where the cap meets the cross inside the joint.

 

Hmmm.....I've never had one ever tighten up on me. I've seen people put them wrong and get them to tight but never get tight with age.

 

I have done alot of wrenching over the years but never done ujoints. Is there a "how to" anywhere on the sight for them?

 

JARHEAD, if I can give any advise about messing with u-joints it would be, if you've never messed with them or even only messed with them once or twice, I would highly suggest that you just remove your driveshaft and take it to a reputable drive-line shop. The best way to remove and install u-joints is with a work bench and vice but funny thing is that a vice is the easiest way to mess everything up too. So for a shop to quickly change the u-joints would be cheap, worry free for you, and they may even make sure its balanced for a minimal extra charge. I say reputable too because you'd be surprised how many guys can easily screw up such a simple job. Now I'm sure guys will post that its easy and to do it yourself and it is a simple job.....which is true for someone who's messed with them regularly. But there's to many things to screw up that would turn your daily driver into a vibration machine or simply cause you to spend more money fixing the problem twice or worse, having to replace something like a crushed driveshaft yoke.

 

after 35+ years in a transmission shop you see a lot of things.

 

They can get tight because of internal rust. Another good indication of a bad or failing U/J is to look for signs of rust at the seals. ANY sign of rust and it's going to fail soon.

 

My fwd ujoint at the support bearing went south on me a couple years back. It was tight and looked good except for the brownish rusty dust around the seal. It ran dry and was shot.

Get Spicer solids.

 

I'm glad you said that because there is a misconception that greaseable u-joints are what you should replace your non-greaseable u-joints with, but thats not true. Non-greaseable are stronger and more reliable than greaseable. And Spicer is probably the best you can buy unless you get some serious high dollar aftermarket u-joint.