Jump to content

JoeH

Pedigreed Bulldog
  • Posts

    2,278
  • Joined

  • Last visited

  • Days Won

    14

Posts posted by JoeH

  1. Id take Allison Dealers advice. My understanding of autos, as it shifts out of one gear into another there's a momentary overlap period where multiple clutches are working against eachother. Harder shifts are because it makes the shift happen quicker, which reduces the clutch slippage durations. In your application i don't see any concerns. Easy life ahead for that Dog.

  2. Slowing down and downshifting should be done in "steps". This isn't an automatic where it's one smooth constant slowdown.  Going downhill, I frequently use the brake to slow down close to idle RPM, then execute my downshift, then resume foot brake.

    If you're finding yourself in situations where you need to have a foot on the brake while downshifting then you're waiting too long to even start slowing down. You're being too rammy. Relax, slow down, take your time. I just went through this training a new driver a year ago.

    • Like 2
  3. It should run longer than that with low oil pressure or low water level. 

    If it's the traditional injection pump then I'd suspect the shutdown lever solenoid. 

    If it's an EUP engine then you can request Blink Codes by holding the Set/Decel cruise switch until the Engine Malfunction Light (lightning bolt) reacts and starts blinking a 2 digit code to you. Example, code 9-2 is engine shutdown without key.  Commonly caused by a loose EECU fuse, but basically means an interruption in EECU power circuit.

    One code is spat out per request. So key on, engine off, hold Set/Decel. When it's done blinking hit it again for next code. Repeat until it starts blinking out the same sequence of codes again. Post any codes here and we'll look em up for you.

  4. You have oil pressure, but your engine shut down light is staying on. How's your coolant level? Also these may use 2 oil pressure sensors. One for the gauge, one for the EECU.  Will it continue to run if you hold down the shut down override switch?

    Can you clarify which fuel system you have? Does this have 6 individual EUP's or one "traditional" style inline injection pump? If you aren't sure then post a picture of the passenger side of the engine, we can tell from that.

    If it has a "traditional" injection pump then disconnect your shutdown lever on the pump from whatever electric solenoid controls it, put it in the "run" position and see if it'll run.

  5. I think this depends on what kind of accident you're planning on getting into. Looking at my trucks, I'd say my DM686SX has the best crash rating.  Frame is made of two 3/8th rails, and the front bumper is massively strong, sticks out a couple feet in front of the radiator. This truck is my Zombie Apocalypse go-to. Currently set up with a 5th wheel for yard work, I'd haul a 7,000gallon 2 compartment tanker trailer, one compartment for passengers and the other for either potable water or diesel fuel.  This truck would plow through any road barriers with the bumper it has.

    • Like 1
  6. I don't think you'll have any thermal expansion issues by adding ribs underneath your hood.  If I get a minute I'll take a picture of the inside of my sailboat.  It has cedar ribs that are fiberglassed to the floor to help give it strength.  It basically creates a fiberglass box channel that gives structure to the otherwise flat panel.

    You could fiberglass in plastic pipe or even foam insulation for water pipes. Metal is going to add a decent amount of weight to the hood, which will make it harder to open, but you don't need anything heavy, just something to hold the shape for the fiberglass resin to set.

    • Like 2
  7. On 1/25/2024 at 3:41 PM, DirtWorx said:

    1999 Mack RD688S E7 misfire under load, cuts out sporadically - injectors, EUP, ECM, or wiring harness?

    1. Engine runs correct under normal operating conditions unloaded.
    2. Engine cuts out sporadically for a split second then comes right back on when loaded or unloaded.
    3. Engine sputters under uphill load until throttle is decreased.
    4. Engine injector(s) disengages and reengages sporadically under uphill load.
    5. Diagnostics shows injector 2 and 3 low voltage.

    Find a solution yet?

  8. Your point #2, is the engine shutting off momentarily? This will likely be a loose fuse for the EECU, I'm guessing this fuse is in the fuse box under the hood. With engine running, wiggle the EECU fuse. It'll probably stall out. It should trip a blink code 9-2 I believe. If your fuses aren't labelled in the box lid then just wiggle the fuses one by one. You'll need to pinch the fuse slot connections a bit tighter, and maybe bend the fuse legs a bit to create more connection. That's what I had to do on my MR688.

  9. 46 minutes ago, mrsmackpaul said:

    A bit of fair sized task your under taking 

    I did something similar on a farm ute years ago

    I was stunned when I put it all back together that everything worked first go

     

     

    Paul 

     

    I'm about $200 into a label maker, between buying it and buying 4-5 roles of the vinyl cartridges that go in it. Pricey, but the utility value is massive.

    This harness will go into storage incase we ever need to utilize it and the engine. I'm sure hoping everything works once I get it all together. 

    Still need to strip this cab down further, patch a hole in the floor, replace some seized rivnuts, pull windshields, sand down and paint the cab, and a myriad of other tasks. Probably needs a heater core.

    The rear window in this cab was a slider, but I'm opting to put the solid rear window from our busted cab into it instead, since the VECU is located just inside the rear window.  Not taking any chances on rainwater finding it's way to the VECU.

    • Like 2
  10. My brothers and I all learned to drive on my dad's 1979 R686ST. Video e it for 6 years while we built a volumetric mixer for a 95 RD688S triaxle we bought. Now I've been driving that for 9 years, and we're phasing the '79 into backup/retirement.

    I like R's. 🤓 Though I do like that Pete, that's the body style I'd chase if I bought a Pete. Though the hood fenders don't have good off-road clearance. Mack's were built for on and off road. Sat up higher.

    • Like 2
×
×
  • Create New...