Replacing DD15 Rear Engine Mounts, What to Remove?

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by PE_T, May 15, 2020.

  1. PE_T

    PE_T Road Train Member

    I have plans on eventually replacing the rear engine mounts on my DD15. Do I need to drop the driveline? What about the transmission? I cannot find any official instructions from Detroit on how to replace the rear engine mounts.

    Initially I thought the transmission needed to be removed to take off the engine mount bolts, but I can confirm that there is space (a little) to remove the bolts. What I haven’t tested is if I can torque the bolts, although I should be able to torque most bolts. I’m thinking I may need a small socket to perhaps make the torque wrench fit on all bolts/nuts.
     
    Last edited: May 15, 2020
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. BoxCarKidd

    BoxCarKidd Road Train Member

    4,435
    6,471
    Aug 26, 2014
    0
    Engine mounts are a product of the truck manufacture not the engine. What are you working on?
     
    PE_T Thanks this.
  4. lester

    lester Midwest's #1 Feed Hauler

    2,918
    7,874
    Jan 2, 2012
    NW, Iowa
    0
    Just because something has a torque spec doesn't mean every darn thing needs torqued. Especially something like engine mount bolts. Just get them good and tight. I own a couple torque wrenches but really only break them out for internal engine work.

    Just my opinion and it's worth just that, nothing. Do what helps you sleep at night
     
    tommymonza, stillwurkin and PE_T Thank this.
  5. PE_T

    PE_T Road Train Member

    I have plans on replacing the rear engine mounts myself, but I want to make sure it can be done without dropping the driveline or transmission. I don’t want to jack up the engine and damage my driveline or something else.
     
  6. PE_T

    PE_T Road Train Member

    I guess you can say I’m a little too crazy about torquing everything. Hahaha. I’m learning that not everything needs torquing. Even Detroit workshop manuals don’t have a torque spec for everything. When they leave it out, I either just give it a good tight or I guess the torque and make notes to myself for future use.
     
    Rideandrepair, stillwurkin and lester Thank this.
  7. BoxCarKidd

    BoxCarKidd Road Train Member

    4,435
    6,471
    Aug 26, 2014
    0
    Most all rear engine mounts can be replaced without removing the transmission. Someone on this forum told me otherwise, I did not argue.
    The one on the left side of a Ford with a 3306 was especially difficult.
    Do not let the engine roll or move toward the mount that is removed. Tighten the bolts back like they came loose.
     
    Rideandrepair, stillwurkin and PE_T Thank this.
  8. BoxCarKidd

    BoxCarKidd Road Train Member

    4,435
    6,471
    Aug 26, 2014
    0
    You can google a bolt torque chart by size, thread and grade. If you find a more advanced chart it will have more variations for shoulder bolts, bolts in aluminum, different types of washers, dry or lubricated. Is anti seize a lubricant?
     
    Rideandrepair and PE_T Thank this.
  9. PE_T

    PE_T Road Train Member

    I’m still learning how to read bolt sizes and grades. Once I get the hang of it, and I can begin using those charts. I’ve known about that method for finding torque specs, but I still find it complicated to understand. Then as you mentioned, there are different torque specs for dry or lubricated threads. Personally, anti-seize is a type of lubricant.

    ProjectFarm YouTuber recently tested out various anti-seize lubricants and it turns out that plain motor oil can function as an anti-seize, although it won’t beat anti-seize lubricants.

     
  10. PE_T

    PE_T Road Train Member

    I did not know Freightliner had workshop manuals. I’ve been trying to access the DTNA Connect site, and I think finally I’ll be granted permission to access it. It looks like they may have some workshop manuals!
     
    Rideandrepair Thanks this.
  11. Rideandrepair

    Rideandrepair Road Train Member

    17,274
    56,071
    Aug 8, 2015
    0
    I changed mine on a 12.7, first time didn’t drop driveshaft. Should have dropped oil pan, and jacked it up, safely. Could hoist it from the top, with proper equipment. However you do it, be safe. I almost lost the tip off a finger.
     
    BoxCarKidd and PE_T Thank this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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