Gearing and pulling, 3.08 gears with Mdrive in a Mack

Discussion in 'Mack Forum' started by Mattmanstroked, Feb 10, 2021.

  1. Mattmanstroked

    Mattmanstroked Light Load Member

    185
    269
    Nov 24, 2019
    0
    Trying to get an idea of how some 3.08 gears are going to pull with a Mdrive and a 445hp in a Mack truck.

    This will be a road truck grossing close to 80k most times. Max speed of 70mph. Pulling tank trailers most of the time.

    Current truck has Cummins 450hp with 13 speed and 3.36 gears. It doesn't pull very hard.
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Concorde

    Concorde Road Train Member

    1,456
    3,317
    Jun 29, 2016
    West Melbourne Florida
    0
    Your problem is low HP..450hp and likely low torque.

    For pulling heavy loads constantly I wouldn’t have anything less than 500hp.

    You have what I call a “Flatlander truck” :)
     
    TripleSix and Bean Jr. Thank this.
  4. Mattmanstroked

    Mattmanstroked Light Load Member

    185
    269
    Nov 24, 2019
    0
    Man running a Mack in the logging woods has a 505hp Mdrive and 3.56 gears. Says he is running in Eco mode and it pulls plenty hard. They usually gross 85k or little more depending how close to the mill they are.

    Have driven a Mack with 445hp and 13 speed not sure on rear gears, they were low cause 70mph is like 1700rpm. It pulled very well.

    I just don't want to get another truck and it not pull better than the one I currently have.
     
  5. Sharky88

    Sharky88 Medium Load Member

    680
    789
    Sep 25, 2013
    0
    I have a Volvo with 2.64 gears 500 up 2050 tq it pulls very well. Mack and Volvo engines are the same just rebranded
     
    Mattmanstroked Thanks this.
  6. Truckwork2461

    Truckwork2461 Bobtail Member

    47
    14
    Feb 10, 2021
    0
    Have you considered a HP upgrade? Shoot me your VIN and I can see what’s available. Some trucks it’s a matter of programming while others require part replacements.
     
    gekko1323 Thanks this.
  7. TripleSix

    TripleSix God of Roads

    16,735
    117,586
    Apr 10, 2009
    Copied in Hell
    0
    3.36:1 gears will pull worlds better than 3.08:1 gears ever could. For a freighthauler sticking with 80k GVW, ideal would be 500 hp, and 3.55:1 gears out back
     
  8. brysol01

    brysol01 Light Load Member

    279
    352
    Nov 2, 2009
    0
    i have a 2020 Mack MP-8 445C 12 spd M drive with 3:11 rears @1400 rpm
    i'm doing 68 just over 7 MPG, with summer fuel
     
  9. BobO1176

    BobO1176 Light Load Member

    61
    101
    Oct 29, 2021
    0
    3.58 and 1350rpm at 62mph on mine. Perfect for my speeds.
     
    brysol01 Thanks this.
  10. brysol01

    brysol01 Light Load Member

    279
    352
    Nov 2, 2009
    0
    i am gonna drop it down , just over the line at 13350 is 65, and see if my fuel mileage improves some
     
  11. gekko1323

    gekko1323 Heavy Load Member

    736
    976
    Jul 14, 2018
    Henderson, NV
    0
    Can you get the specs on any truck with the vin?
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  • Draft saved Draft deleted