Squeak/Chirp in 2WD but not 4WD?

I've got a rotational squeak/chirp that has been coming off/on for the last 2-3 months. It doesn't always do it but the other day, I had the bright idea to see if it did it in 4x4 and it does not. Usually starts making noise around 30mph+ and continues from there. Anything below that speed, it is not present.

What would you look at first? U-Joints? CV Axles? Wheel bearings? I've looked over the basic stuff and nothing stands out. It comes and goes as it pleases so I can never pin point when/where its coming from.

 

Those sound like good things to look at and rotors and carrier bearing.

 

I'm tempted to say u-joint(s) based on your description but noises like that can be tough to pin-point until they're constant or near-constant. If you can get all 4 wheels off the ground and running safely it may help diagnose. If it doesn't occur under those conditions I would say wheel bearings are more likely to be the issue since now the wheels are unweighted. But again, tough call since it isn't a constant noise yet. Keep us posted.

 

Have you ruled out chipmunks? Those little bastards squeak like crazy.

 

I’m thinking at this point, it could only be U-Joints. I’m planning on having them done next month along with new CV axles. Just waiting to hear back on how my guy is going to warranty my leaking axle seals.

 

Well, I shot some WD40 on two front u-joints and the sound has almost disappeared. Looks like some new ones are in my future.

 

You have 4x4, you don't have zerks on your U-joints?

 

Yes 4x4 and they do have zerks. I posted in another thread but none of them will take grease.

 

If they are screw in zerks, clean them up real good on the outside and them crack em loose like you would a brake bleeder. Then try to give em some grease.

 

I've messed with them a few times and the no luck. I removed one and the spring on the inside of the check valve/ball flew out and got lost. The zerk is back in but the ball valve is missing. I think at this point, I am going to replace them all since they have almost 200k on them. They are cheap enough and it's something I'd rather not worry about.