I have a grinding noise coming from my front passenger tire. I already changed out the solenoid, check valve and pressure checked my vacuum lines. The sound almost sound more like my tire is rubbing inside the wheel well with a slight rattle. It only happens while heading up hill or slightly on the throttle. The reason I'm not sure if it's the IWE is the sound still occurs while I'm in 4wd high. Anything else it could possibly be? Thanks

 

If it has made the sound for too long and was not fixed, the IWE grinds away and it grinds away the splines on the hubs, so that even when the vacuum system is fixed it grinds because the repair waited too long.

 

Does that mean the actuator along with the wheel bearing assembly needs to be replaced? Or is there another part that will need replacement also? Just trying to get all the parts ready for my mechanic so that's it's a 1 time repair. Thanks

 

The hubs have a spline on then that engages the teeth of the IWE as do the axels have splines but they are always engaged with the IWE teeth.

So when the vacuum starts to get weak because of the check valve, the IWE only partially disengages from the hub splines and starts to wear on the IWE teeth, putting the unit into 4wd drops the vacuum out and the IWE engages the hub spline, then the noise goes on and on and is ignored and vacuum system is not fixed so eventually the IWE gets worn enough than when it engages the hub splines in 4wd it slips grinding away at the hubs when it should be locked. Will your parts supplier let you return any parts you do not open? if so you can have all the possible parts for your mechanic and replace what is needed and return what is not.

 

Honestly, the only way to tell is to tear it down and look. I’ve seen the rotor dust shields have a bolt loosen and grind on the rotor causing similar sounds. Also seen brake caliper mount bolt come loose, fall out and the caliper rub on the wheel. Both sounded very very similar to an IWE. Have also seen wheel bearings go bad and grind like that.

 

I changed out my solenoid,check valve. New wheel bearings and actuator. Pressure checked vacuum lines. The grinding noise frequency has diminished immensely with much improvement. But......the noise is still their intermittently although not as frequent it still occurs when I'm accelerating steadily. Any other ideas that might be causing this? I plan on rechecking the vacuum lines later today and see if there is a leak I might have missed. My friend said he did not see any damage on the output shaft but is uncertain if the hubs were locking if it could have damaged the drive axle. But if it was a axle issue would it be more constant? Thanks

 

Hint, when you accelerate, there is less engine vacuum to keep the IWE from trying to engage.
Vacuum is what keeps them >dis-engaged< when 4wd is (not) intended.
When the engine is shut off, they actually do engage. No vacuum present to pull on the IWE.
May sound backward but is the way the system works.
Good luck.

 

I also would check the lines for a possible leak. Next I would either put in 4A or disconnect solenoid for a drive and see if, 'when fully engaged', do the slip and chatter a bit under acceleration? Keep us posted .

 

I had a similar noise. It was driving me crazy because it wouldnt go away in 4WD.

I ended up looking under there, and there's a piece of exhaust that goes across the truck sideways just behind the front wheels. I noticed there was an indent on it like a clamp had been there. It ended up being a heat shield clamp that had rusted off and when rpms were low, it created enough vibration to get it to rattle. i put a hose clamp on it and its been fine since!

worth a shot!

 

My IWEs were replaced twice under warranty. When the issue returned, it sounded the same, so I removed and inspected, but noticed the wheel bearing had a slight noise spinning by hand. The issue returned after replacing the hub assembly.

The second time around the CV axle was replaced and issue resolved. The axle sounded like the IWE and hub.