Grinding noise

Discussion in 'Questions From New Drivers' started by Jcleve, Jul 18, 2019.

  1. Jcleve

    Jcleve Bobtail Member

    7
    12
    Jul 18, 2019
    Hershey
    0
    I've been driving for less than a year. Recently my 2016 Mack pinnacle day cab I started having a grinding noise from the gearbox. This happens in the upper gears 8th 9th and 10th mainly. It happens when I'm trying to accelerate in any one of those gears when I press the throttle go be a loud grinding noise and a spike in RPMs and no increase in power. On the plus side there's no loss of power. Any ideas would be greatly appreciated
     
  2. COBB2070

    COBB2070 Medium Load Member

    325
    341
    Jul 8, 2018
    SoCal...The OC
    0
    Get the gear box oil changed. Probably going find a good bit of metal in there.
     
    okiedokie and Lepton1 Thank this.
  3. starmac

    starmac Road Train Member

    3,716
    5,799
    Apr 11, 2019
    Fairbanks Ak
    0
    A spike in rpms??
     
    magoo68 and Intothesunset Thank this.
  4. Jcleve

    Jcleve Bobtail Member

    7
    12
    Jul 18, 2019
    Hershey
    0
    When I'm driving an eighth, 9th or tenth and I press the throttle the grinding noise begins in the RPMs will jump 2 to 300. I assume that's because I'm applying throttle obviously but the power is not providing torque. That's just my guess.
     
  5. Jcleve

    Jcleve Bobtail Member

    7
    12
    Jul 18, 2019
    Hershey
    0
    I'll recommend that to the mechanic when I bring it in. It's a company truck I just don't want to be on the side of the road
     
    COBB2070 Thanks this.
  6. Intothesunset

    Intothesunset Road Train Member

    1,650
    3,114
    Apr 15, 2019
    truck
    0
  7. Brandt

    Brandt Road Train Member

    2,216
    2,095
    Sep 17, 2012
    0
    RPM spike would be the clutch slipping. Maybe clutch is making noise. I never had one make noise but when they wear out they slip
     
  8. starmac

    starmac Road Train Member

    3,716
    5,799
    Apr 11, 2019
    Fairbanks Ak
    0
    If the rpms are truly rising, without the truck speeding up, it will be something to do with the clutch. I can't explain the grinding noise, but if it is gaers and it slips, you would be dead in the water.
     
    MartinFromBC, Intothesunset and Jcleve Thank this.
  9. Jcleve

    Jcleve Bobtail Member

    7
    12
    Jul 18, 2019
    Hershey
    0
    Putting it into the shop tomorrow. I just wanted an idea how to explain it to the breakdown Department. Thanks for all the advice. I had a feeling was along those lines but I wasn't certain
     
  10. FoolsErrand

    FoolsErrand Medium Load Member

    628
    1,759
    Sep 15, 2017
    0
    May just need the clutch rod adjusted. Does the clutchbrake work?
     
    MartinFromBC Thanks this.
  • Draft saved Draft deleted