Bearing/Rotors Question

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Brad Wissinger, Jul 24, 2013.

  1. Alright, go another issue I need some assistance with. I recently put on a 6" suspension lift running 35" Nitto Mud Grapplers. When I had the rims and tires off and everything all disconnected, I checked my pads and rotors (they looked fine, minimal wear for front pads and rotors). I had replaced my hubs about 2 months before doing all of this (so about 6 months ago.) About a month ago, while driving into work I was going about 10 or 15 and heard a sound (metal to a rubbing sound) but not a constant one, like it would come in for a second while the tires were in a certain position in their revolution. So I think nothing to serious of it, and keep driving it (it's my daily driver/weekend toy). Now I am up in Connecticut, and had the truck shipped up here via an open-style car hauler. I get the truck delivered to my door, pay the guy, and he is gone. I test drive my truck and the sound that I described earlier (metal to metal...rubbing sound) that WAS subtle, is now EXTREMELY loud. I haven't jacked it up to check the hubs/bearings, but any ideas on what it could be?

    The only troubleshooting I've done is:
    1) Driver window down, passenger window up, 10-15 MPH = sound is LOUD.
    2) Driver window up, passenger window down, 10-15 MPH = sound not so loud.

    Other info/background:
    1999 (and a half) 1500 Z71 4x4 5.3L with 6" Rough Country lift, 315/75R16 Nitto Mud Grapplers. Stock gears.
  2. j cat

    j cat Epic Member 5+ Years 1000 Posts

    the question I ask is are the hubs china crap ? if so that may be the reason. make sure you properly torqued the HUB NUT . I believe its 157 FT LBS. no air guns allowed.
  3. Hubs are from Napa ($129/ea), the first ones I got we're the cheap China junk. The big nut is properly torqued to 157 (+5/-0) ft/lbs. I don't use a lot of air tools. Was raised without them, so don't tend to use them now. haha
  4. j cat

    j cat Epic Member 5+ Years 1000 Posts

    check the transfercase fluid for trac II fluid to be blue in color. if the fluid is black the sound is most likely this.
  5. Are the rotors being warped a possibility?
  6. j cat

    j cat Epic Member 5+ Years 1000 Posts

    No ! but it is possible that the brake pads were installed wrong. clips could be making the sound. or the brake pads are worn out. since you just worked this, I doubt this would be it, BUT ?

    after the tranfercase check then the U joints . are the U joints straight or at an angle. the more angle the faster the failure.
  7. I haven't worked the brakes since I bought the truck two years ago. Where can I get the Trac II fluid? Are there any replacements for it, like Royal purple or Lucas?
  8. j cat

    j cat Epic Member 5+ Years 1000 Posts

    GM Trac II is a GM dealership fluid .secret formula. why is the fluid black ? what about brake pads worn ?
  9. So I just checked the fluid and it wasn't blue...was black.

    On the passenger side, one of my pads looks like it's wearing pretty heavy, and my driver side caliper has a little play in it (side to side).

    Is that normal to have some play. Shouldn't it be solid? I know now the culprit is most likely the transfer case. I checked my front pumpkin as well and the little gear oil in it was blackish-brown. So looks like I need to change transfer case fluid, front diff oil, and front pads. Anything else I should look for while I'm at it?

    Can I just go into a Chevy dealer and order that transfer case fluid? I found something on Summit Racing's website that says it's the right stuff, but should I go with that or the stuff from Chevy?
  10. GM Customer Service

    GM Customer Service Epic Member 5+ Years 500 Posts

    Hello there,

    If you private message me your zip code I can do some research and I can find out if you can or cannot order the Transfer Case Fluid from your local Chevrolet dealership.

    Jennifer T.
    GM Customer Care

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