Bad axle u-joint?

So I have this periodic/intermittent harmonic vibration in my Jeep. It sounds and feels like it's coming from the driver's side front tire area. I pulled the front driveshaft to make sure it wasn't an out of balance or bent driveshaft. Didn't make any difference. So as I was driving today, it seemed that the vibration only seems to come when the wheel is turned....regardless of how slightly. This led me to believe it was a front axle u-joint in the dana 30 going bad. But I don't see any leakage, it doesn't appear to be loose at all, but it also has no valve to grease it, so I'm thinking it may have just dried and be slowly wearing away the needle bearings.

Is there any way to tell if the u-joint is on it's way out? I'd just wait until it snapped, but I don't want it taking the ear(s) of the axle ends in the process.

or should I just bite the bullet and replace it, and if it doesn't make any difference, keep the old one as a spare?

you check the u-joint by using a prybar and checking fo any movement or play in the joint.

IMHO, it sounds like a bad hub or a warped rotor.

U-joints (and unit bearing/hubs) are a normal maintenance item. They are replaced when they wear out, make noises/vibrations/clunks, or break.

pull the shaft and replace it. its not much harder or longer than doing your brakes. theyre like 15$ or less for the joint. while you have it off you could throw a new bearing on as well. they are 98$ each at autozone.com and rockauto.com for timken

if its more of a vibration or humming i think its the hub. thats how it was for me. id pull the hub and check to see how smoothly it turns or if it has any play

ok, so I just got home from work and went out with a prybar and floor jack and can't find anything loose...no play, no grease, no grinding. I was noticing that this side has a bit of cupping on the tire and appears to have to much toe out....could a bad alignment do this? And my fat ass sitting on top of this tire is what makes it seem worse on this side?

Guess I'm due for a tire rotation anyway, so that will answer that question. Thanx heaps for the input and keep any other ideas coming....I have limited time to work on it, so the more ideas I can thoughtlessly implement in one sitting the better

BTW, when I checked for play in the hub, I didn't remove it from the vehicle, I just removed the tire, brake calipers, and brake rotor.....could the wheel nut be on tight enough to hold it in place even if the bearing is going bad?

EDIT: Oh, and as for the rotor, I tend to think that's ok since I have not vibration in the brake pedal when braking, and even when I can feel it in the brake pedal, it's no worse than the floor board or steering wheel....plus, it seems like the few opportunities I have to get it up to 75-80, the issue appears to go away....but with all the cops out lately, that opportunity is few and far between, so it may just be coincidence.

i went through the same thing. thought my u-joints were going, got it all apart, spun the hub by hand off the axle and it wasnt smooth which ended up being the source of my noise. didnt appear when it was on the axle though. just my .02

U joints have a tleast two failure modes. One is being tore up loose. That is easy to spot. The other is being froze up dry. You have to pull the axle to find those.

winterbeater said:

U joints have a tleast two failure modes. One is being tore up loose. That is easy to spot. The other is being froze up dry. You have to pull the axle to find those.

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No need to pull the axle. Just jack up that side, crank steering all the way right or left, and turn the wheel. If the joint is binding, you'll feel it immediately.