Breaking engine mounting bolts

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Perchie15, Jan 23, 2024.

  1. Perchie15

    Perchie15 Light Load Member

    233
    70
    Aug 16, 2021
    0
    This is what we thought of doing also drilling them out that way if they break then easy change out ha! But obviously it’s not proper way either.
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Perchie15

    Perchie15 Light Load Member

    233
    70
    Aug 16, 2021
    0
    definitely not cheap $1200 for the one mount that I accidently ordered when I wanted just the bolts. I hear ya it be super easy if the tranny was out already other than that so hard to deal with everything in the way. PS side would be super easy to change though lol like why does it have to be the DS always breaking
     
    Rideandrepair and Diesel Dave Thank this.
  4. Rideandrepair

    Rideandrepair Road Train Member

    17,333
    56,238
    Aug 8, 2015
    0
    Drivers side gets all the torque when taking off. Always first to break. Big Bad 600hp Signature series. Nice. Maybe you can chain it till you can replace all of them. We used to do that on the old V8 clunker cars. Big block B body 62-73 Plymouths and Dodge left side motor mounts weren’t available in the 80’s. Had to improvise or use solid steel mm mounts.
     
    Perchie15 Thanks this.
  5. pushbroom

    pushbroom Road Train Member

    1,779
    7,312
    Sep 1, 2012
    0
    It was the original Paccar field fix before the updated 4 bolt mounts were available. Ive drilled alot to 3/4 and never had a failure.
    So options are drill them to 3/4 and bolt and nut them, update to the newer 4 bolt mounts, or keep breaking mounts.
     
    Perchie15 and Goodysnap Thank this.
  6. Perchie15

    Perchie15 Light Load Member

    233
    70
    Aug 16, 2021
    0
    Goodys
     
  7. Perchie15

    Perchie15 Light Load Member

    233
    70
    Aug 16, 2021
    0
    goodysnap suggested do what you said he took my VIN number and came back with your suggestion. Cuz I’d did call Peterbilt about the numbers goodys sent me and said it is not on the application won’t work. So I’ll take the typical bolt that’s grade 8? and call it good I guess! How long should it be to get washers and lock nut on it? Thanks alot for the help.
     
  8. pushbroom

    pushbroom Road Train Member

    1,779
    7,312
    Sep 1, 2012
    0
    Grade 8 3/4 bolt. Not sure on the length, you will have to measure. Going to have to remove the mounts off the engine and off the frame rail for drilling. Tapered 3/4 reamer helps.
     
  9. Perchie15

    Perchie15 Light Load Member

    233
    70
    Aug 16, 2021
    0
    really gonna have to remove them? #### that does not sound like fun! By the looks of it the driver side is like impossible to get it off without having the tranny out. Is it possible ofcourse with all the #### wires and lines In the way seems off lol.
     
  10. Goodysnap

    Goodysnap Road Train Member

    3,716
    9,022
    Jul 12, 2017
    0
    You’ll never get them drilled out in chassis. When he says a tapered reamer helps. They drill very hard. The ones we did got drilled out in the drill press then put in.

    or you order all new stuff from the chart provided. The parts guys will tell you the upgraded parts are not on your chassis. This is an upgrade/ modification.

    If you willing to do the drilling. It will be cheaper to drill out the ones you allready have.
     
    pushbroom and Perchie15 Thank this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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