2003 Exp Sport 4WD Grinding

[STL-guy]

Having a problem with my 2003 Explorer Sport 4WD, 4.0L, 46,000 miles. When in 4WD high, getting a grinding noise while turning in either direction. Runs fine in 2WD. Discovered the following while investigating:

While the whole truck was jacked up and in 4WD, turning does not cause any noise. When in drive both rear wheels turn, drive shaft turns, front passenger turns, Driver wheel and CV DOES NOT turn.

With the engine off in 4WD and spinning the wheels by hand, the front driver turns the front passenger, and the drive shaft does not turn. The passenger turns the driver and the drive shaft does not turn. Can not turn the drive shaft by hand.

With the engine off in 2WD the front driver turns the front passenger and the drive shaft does not turn. The Passenger DOES NOT turn the driver, and the drive shaft turns. Spinning the drive shaft turns the Passenger only.

Know that something is wrong and looking for help with diagnosis, and next step advice.

Thanks
STL-Guy

 

[STL-guy]

Next steps

After listening to the grinding noise while turning, a mechanic said that I should replace both of my hub bearings. Does this sound right to anyone?

 

[Cstoliker]

I doubt it is bad wheel bearing if it does not produce the sound in 2wd. The fact that the passenger wheel spins while the drivers does not tells me that there is some rolling resistance in the driver’s wheel or axle. Could just be a sticking caliper. But nothing to worry to much about.

Correct me if I am wrong but in 4WD-HI the T-case is locked (true 4x4)? So grinding while cornering on dry pavement is normal from the front and real wheels binding. Unless we are talking about 4WD Auto. The way I understand it 03 explorer sports have 2wd/4wdHi & 4WDLow. Not 4wdAuto or AWD.

Unlike AWD or 4WD/Auto. 4WD/HI is true 4x4. The front and rear wheels are locked together and can not spin different speeds. When you take a turn the front wheels need to travel farther and therefor faster then the rear wheels but can not witch causes binding. 4WD hi is great for off roading & snow but should not be used on dry pavement where the wheels can not slip.