Grinding/rubbing sensation through foot pedal and floorboard

[tcbrad98]

2017 Limited has a grinding/rubbing sensation/sound through floorboard and pedals.

I have replaced the hub/bearing units, IWE's(pulled vacuum and verified they worked, both old and new ones), solenoid and check valve.

Have cleaned/inspected all mating surfaces and gear teeth. Pulled a vacuum on the lines to verify they work and hold vacuum.

Swapped tires and even put on the spare.

I found 3 seized brake caliper slid pins on the front, so replaced and lubed caliper bracket, boots, and pins. Checked the brakes and brake shield for contact with anything, no issues.

Even check the rear bearings in case it was being transmitted through the frame.

The sound/sensation is still there!

You can't hear it with the window down, but can feel it most strongly under mph.

The sound does not improve or change in 4A or 4 High.

Even tested the hubs with the wheels/rotors off to make sure the system is pulling vacuum at startup and activating the hubs.

Have even disconnected the hub, vacuum line, put the vacuum gun on it, pull the vacuum and driven with the vacuum manually pulled and maintained, it does not affect the sound.

Doing tight circles the vehicle does not hop like the hubs are locked, like you would experience with manually lock tubs. They do hop when it is in 4 auto as you would expect.

This is leading me to believe it is not the hubs or the bearings, but I am at a loss as to what else could be making that sound.

If the hubs are unlocked, the bearings are good, and the brakes are not making the sound, what else could be rotating that might be making that sound?

Anyone have any ideas?

 

[tcbrad98]

This weekend, I’m going to check the new joints on the front and rear driveshaft.

I know that the front shaft should not be turning, but I will check it anyway.

 

[tcbrad98]

While I’m at it, if I do not find any issues with the U joints, I will jack the front end up completely disassemble the whole thing, and then reinstall verify the wheel ends and the hub units along with the CV axles.

I really do not think it is the U joint because there is no thunk , it is a constant rubbing sound, sounding very metallic.

 

[tcbrad98]

Finally figured out the issue, the spring from the original IWE that provided tension to the rubber seal was wrapped around the cv axle making the metal rubbing noise.

We didn’t notice the damage to the original gasket with all the old black grease.

I took everything apart again yesterday, cleaned all the new grease off and noticed the spring wrapped around the axle.

Compared it to the new IWE waiting to be installed on the passenger side an realized where the spring came from.

There doesn’t appear to be any damage to any splines or teeth.

Regreased everything and put it all back together.

No more noise!

 

[AWAR]

Glad you found it, thanks for the report. One more failure point to remember!

 

[tcbrad98]

Update:

I was wrong, that spring was actually from the replacement IWE hub that somehow failed.

I replaced that IWE hub again and replace the CV axle this time.

The only thing left that could possibly be rubbing that I can think of or grinding or making a cyclical noise is the tires which are at about 5/32 and are due to be replaced this spring.

Unless somehow the ABS hub that I replaced two months ago has gone bad, but the sound was the reason I replaced that ABS hub unit in the first place. So it was there before that unit was replaced.

I guess the next stop is new tires and we will see if that changes things.