99 tahoe rear axle

Discussion in 'Engine & Drivetrain' started by Rick_Grff, Apr 2, 2019.

  1. Rick_Grff

    Rick_Grff TYF Newbie

    Posts:
    9
    Likes Received:
    0
    Joined:
    Sep 13, 2016
    Name:
    Rick
    With the rear end on jack stands, emergency brake off, transmission in park, front tires chalked. Should my rear tires be able to rotate because they do. They rotate in the opposite direction.
     
  2. Dcmaynor

    Dcmaynor Full Access Member

    Posts:
    481
    Likes Received:
    230
    Joined:
    Jan 15, 2018
    Location:
    OH
    Name:
    Dana
    That’s normal. If you had a locker, limited slip, etc differential it might be difficult to spin while in park since the mechanism would cause resistance. If you place it in neutral, both would rotate in the same direction if your diff was limited slip, locker, etc.
     
  3. Sean James

    Sean James Member

    Posts:
    39
    Likes Received:
    22
    Joined:
    Dec 8, 2018
    Location:
    Mountains of Utah
    Name:
    Sean
    Thats for making really tight turns. Seriously, when both wheels are on the ground, everything works. This is totally normal. Thats why they call it a differential, one spins a different" way than the other when its off the ground :)
     
  4. Rick_Grff

    Rick_Grff TYF Newbie

    Posts:
    9
    Likes Received:
    0
    Joined:
    Sep 13, 2016
    Name:
    Rick
    Thanks for the answers. I'm still trying to figure out what's clunking when I leave a stop sign. I removed the driveline and there is some side to side movement from the yolk on the pinion gear. I drained the differential took off the cover there is no metal chips or flakes on the magnet what so ever. There seems to be alot of backlash when spinning the pinion gear. Nothing seems wrong inside to be making a clunking sound when leaving a stop sign. I'm lost now I don't see how the brakes would stick. If I use the emergency brake to stop it doesn't clunk. Did I just answer my problem? Its got to be the brakes then right?
     
  5. drakon543

    drakon543 Full Access Member

    Posts:
    1,159
    Likes Received:
    316
    Joined:
    Feb 15, 2016
    Name:
    james
    i dont have any side to side movement in my driveline. the tcase has an output shaft bearing then the universals then the rear diff input bearing. you shouldn't have any movement besides rotational or the front spline moving in or out of the tcase as your rear moves up or down. if you have movement outside of that you found your clunk. also rear drums can be noisy or even completely bind up if the pads are put on backwards.
     
  6. SnowDrifter

    SnowDrifter Full Access Member

    Posts:
    1,225
    Likes Received:
    701
    Joined:
    Sep 5, 2016
    Location:
    Washington. The desert side not the Starbucks side
    Name:
    Chris
    Normal. It's how diffs work. If you have a locker and want to see it work, or want to see if you have a locker, grab one tire and spin it real fast
     
  7. alpinecrick

    alpinecrick TYF Newbie

    Posts:
    23
    Likes Received:
    7
    Joined:
    Mar 5, 2019
    Location:
    Western Slope of Colorado
    Name:
    Casey
    Driveline clunk on GMT400's is a very common problem. The output on the T-case (NP241's, 243's and 246's) and the slip yoke on the driveshaft are splined, and the splines bind up when starting out or when the 4L60E's shift, sometimes when they 3-2 or 2-1 downshift also. The fix is a nickel plated slip yoke for the driveshaft. They used to be in the $250 range, but I see Amazon has them for $100. Don't know if it is the same quality as the $250 one.
    https://www.amazon.com/APDTY-708613-Driveshaft-1992-2005-01-04-17-004/dp/B00C8E8BH0

    Don't grease the slip yoke, it will temporarily stop the clunk, but the clunk will return in a couple thousand miles and allegedly will contaminate the T-case fluid. GM even has a bulletin out that says not to.
     
    Last edited: Apr 10, 2019
  8. Rick_Grff

    Rick_Grff TYF Newbie

    Posts:
    9
    Likes Received:
    0
    Joined:
    Sep 13, 2016
    Name:
    Rick
    Clunking problem solved! The driver side rear brake was sticking I went with the cheap wheel cylinder replacement a few months back. It was only pushing out on one side causing the brake pad to get stuck and the return spring didn't return until I started moving the clunk would come from the slop in the pinion when the brake released.
     

Share This Page