dachmingen

Just today I started hearing a grinding/rubbing noise coming from the front end of my truck. The best way I can describe it is that it sounds like a cross between water blasting the underside of the truck and a tire rubbing the fender. The noise is cyclical and constant but at a slower rate than the RPM of the tires. It also get louder after driving at higher speeds for a minute or two even after slowing down again. The sound seems to diminish or even stop when turning left but turning right has no effect.
Some other info that may or may not be related to the issue is that the ABS kicks on everytime I drive the truck. After driving for a bit and having the ABS trigger during every brake, the ABS light comes on the dash and then the ABS no longer triggers (I believe this is because the truck is sensing the error so it shuts off the ABS). Shutting off the truck resets everything and the process begins all over again on next startup. I'm fairly sure this problem is something to do with a bad ABS sensor so I'm not overly concerned about it but thought I'd mention it in case I missed something. I also just replaced the driver side brake caliber yesterday since it was seized.
I've read a lot of threads saying that its the IWE Solenoid or a vacuum hose but switching to 4x4 has not impact on the sound so I'm skeptical that its the problem.

Please help!

who_knos

Im going on a limb......bad wheel bearing/hub assy. Not super pricey and a easy swap. Scan the abs code, that will tell you what wheel. Ive never seen it but maybe a loose cv shaft nut......highly unlikely but maybe.

dachmingen

Thanks for responding so quick!

However, I just looked up some videos on bad hub/wheel bearing noises and it doesn't seem to match. A bad hub seems to produce a more constant grinding noise whereas my noise is more intermittent. I tried to record a video of the noise but its pretty faint on the camera phone. The link to the video is here:

Hopefully it helps with any diagnostic guru's out there.

zapperman

Sounds like your IWE actuator to me. Just did mine for the same reason. But I also changed out the hub/ wheel assembly while I had it apart. When I spun it while jacked up, it was quite obvious the bearings were also shot. Smooth as silk now...and a cheap and easy fix.

who_knos

At first with the noise I thought IWE, a easy check would be to either put in 4wd or unhook the vacuum at the actuator on the firewall and see if its gone. The only reason Im thinking hub assy is due to the abs light kicking on and it kinda changes when turning. Maybe still scan the abs light and if its a front wheel code start there, I wouldnt think side load would change a IWE noise, but then I have been wrong before.....

BadFish523

If the IWE is completely shot then putting it in 4wd will not always make the sound go away. Jack up the front end, truck off spin the front wheels and the front axels should spin with the wheel. If not then you have a problem. If they do then start the truck and spin the wheels in 2wd and the front axels shouldn't spin, if they do then you have a problem. If all that works then put it in 4wd and spin the front wheels and the axels should spin with the wheels, if they don't you have a problem. This is an easy, and free way to test if your 4x4 is working properly.

who_knos

Very true and also when the front end is jacked up you could test the wheel bearings for movement as well, but the IWE wont set a abs code. Maybe there is 2 different problems, I have had a IWE get froze in the unlock position as well.

BadFish523

x2^^^

dachmingen

Checked the iwe using StephenG's recommendation. Everything checked out ok.
I checked the passenger side bearing. There is a lot of movement of the tire and it makes a loud grinding noise when I spin the tire. This seems to be the problem. I'll change it tomorrrow and hopefully that solves it.
The thing that steered me away from this check in the first place was that is didn't exhibit any of the characteristics of a bad bearing (changes with turn direction, loud and constant humming/grinding, etc.)
I'll post the results when complete.

who_knos

Good deal you found something, theses 2 statements is why I thought wheel bearing.

The sound seems to diminish or even stop when turning left but turning right has no effect.
the ABS light comes on the dash and then the ABS no longer triggers (I believe this is because the truck is sensing the error so it shuts off the ABS).

If a bearing is bad enough it changes the distance or even rubs the abs sensor causing the error. I have seen them them bad bad enough that the rotor is the only thing keeping the wheel on and the vehicle would only backup due to the binding when trying to go forward.