Wheel bearing or U-Joint noise?
 

Hi!

I recently had both front wheel bearings replaced on my 97 Silverado because of a "noise" at speeds between 60km/h and 100km/h. The noise was like a "low-frequence grinding" -whoaaaam, whoaaaam, whoaaaam...-, especially in curves to the left. The replacement of the wheel bearings didn't change anything.

So now I'm suspecting the U-Joint because in 4X4 mode (only), when I left off the gas let's say above 100km/h, there's a vibration in the steering wheel until the truck reaches about 50km/h. The vibration is not present while accelerating, only while decelerations. The truck only has 130 000km and was always well-maintained. It does it with both winter and summer tires, which are brand new.

So what do you think it might be?
Thank you very much.

RE: Wheel bearing or U-Joint noise?
 

Check your font half shafts too. I bet one of the boots is ripped and all the grease is gone or the grease is grimey as hell. They aren't too expensive to replace. If thats your problem replce the entire shaft, not just the boot. Then check your U joints and front diff for fluid level.

Some noise is common, but the vibration is not. Every GM truck I've wroked on owned and driven has had some low frequency noise while in 4WD. But its not very loud, like a low hum almost you might even feel it in the floor a little.

RE: Wheel bearing or U-Joint noise?
 

I'd like to clarify that the noise occurs in 2X4 and it is loud but the vibration occurs in 4X4 only. I can tell the difference between the 4x4 noise and the one in 2X4.

Thanks for your input.

RE: Wheel bearing or U-Joint noise?
 

Ok then try the idler arm. When they fail its hard to tell but on that chassis it is common for them to fail. Check all U-joints too for noise and play just to be safe. You MIGHT have to have your tires rebalanced too, but it sounds like an idler to me. Not expensive or difficult to replace so don't worry.

RE: Wheel bearing or U-Joint noise?
 

So the U-Joint could be responsible for the vibration in 4WD and the idler arm for the noise which sounds like a defective wheel bearing?

Thanks again

RE: Wheel bearing or U-Joint noise?
 

Vice versa, the U-joint can cause both but more than likely the noise. The idler is part of the steering. It acts like a stabilizer so when it wears out, it tends to make the steering and front suspension bounce. Either that or the tires are in need of rebalancing.

It will probably be trail an error but this should help:

1. U-joint - Sounds like grinding of metal. Can cause vibration.
2. Tires - If they are out of balance they will cause hopping and or vibration between 50-70 mph (typically 65). Can be felt in steering if the front tires are out and in the seat of your pants if it is the rear tires.
3. Idler Arm - Will cause steering wheel and/or front suspension to bounce or vibrate on bumps and especially around turns. Will cause uneven tire wear.
4. Half Shafts - Will grind like a wheel bearing when in 4 wheel drive if the grease is gone or they are worn out. Might cause vibration but I doubt it.

RE: Wheel bearing or U-Joint noise?
 

my 2000 truck does the same thing when the steering wheel is to the left i makes that .. whoam.. whoam whoam but if the steering wheel is in the center it doesnt make a noise. it sounds like something is is rubbing on the left... this happened after i went mudding i know my wheel bearing on the right is gone and needs to be replaced but there is also a noise coming from the left when its cold and i hit the brakes it makes a constant grinding noise.

Hi I have a 2000 Ford Expedition just under 150k miles, whenever I make a right/left turn and step on the gas, it feels like something is slipping could it be the same thing, bearrings/u-joits/shaft/idler?
Thanks