JoeH

If 4 is better than 2, then 6 is better than 4!

If you need to pull the cam out, use zip ties to hold all the lifters up. I managed to pull the cam out as well as one lifter on our spare motor without having to take the oil pan off. (Our spare motor is bolted to a homemade engine stand that makes oil pan removal difficult, but let's us move it around on the forklift). Stuff the old cam in to keep the lifters from dropping during storage. The lifter was a challenge to get out, I had to make some sort of a rod to reach through the cam bearing assembly to catch the lifter from falling into the oil pan.

Can't get the cam through the dealer anymore, I'd hang on to that motor for parts. We have one from 81 that's given parts to most of our fleet.

I'm still lost as to what is being asked. In "normal" operation, al it takes is one wheel on either axle to lose traction and spin and the truck is stuck. If you engaged the power divider switch on top of the dash then it requires one wheel on each axle to spin in order to get stuck. Mack makes a "full locked" setup that has ANOTHER switch, this one locks left and right wheels together so by using both switches if requires all 4 drive wheels to spin in order to get stuck. On ordering trucks no one knows about the full locked option so there's very few trucks that have it. Is this a case of misunderstanding how your axles work? Or is there actually a problem?

On my android I have to crop them sometimes in the photo app, then upload the cropped photo.

Air filter housing nuts are plastic, don't overtighten them they strip out real easy.

They limit torque in low gears.

If you have a coolant filter it would be on the top front of the engine, above the fan belts. I think the Mack coolant filter has an additive in it that "recharges" the pH? of the coolant. Changing this filter too often can cause the coolant to become corrosive via electrolysis (I think). Someone here wrote a test procedure to test the conductivity of the coolant with a volt meter. There's a certain ohms range it's supposed to be in. Outside of that can be problematic. (never concerned us much...) As with all things, "Trust but verify!"

We ALWAYS prefill oil filters, and we usually prefill fuel filters. If you don't prefill the fuel filters it sucks to hand prime the fuel system. If you DO prefill the fuel filters it's a simple matter of just starting the truck and revving the engine a bit to help carry it through any stumbling as the air pockets in the top of the fuel filters comes through the system. I think it's easier to hand prime a truck with full fuel tanks than low tanks. Less "feet of elevation" for you to draw fuel up. Don't know how much of a difference it makes.

Incase no one's mentioned it, always check to the engine to make sure the filter o ring came off with the filter. Also always rub oil or fuel on the o ring on the new filter before install. Lubricates it so that the o ring won't "bunch up" on install. Dry fuel filter o rings will bunch up and suck air in. Filter usually states instructions: spin it on to contact (not hand tight) then tighten either 3/4 turn or 1 full turn. I've never had a problem with removing *my* oil filters with our nylon strap wrench, though we also have an assortment of the metal band wrenches.

+1 on boost gauge. You won't see much activity on that with an empty truck. Throw some weight on there and it should get up to roughly 25 on a hard pull.

How about tie rod ends, drag link etc...

If you've only got 50 miles on the truck it sounds like someone may have sabotaged the engine shutdown light. It's not unheard of to have a seller pull a bulb out to hide problems they're too lazy and cheap to fix. Lightning bolt is the "Check Engine Light", it should come on with initial key on, then go out after a few seconds, unless there's an active fault code. Engine Shutdown light *should* do the same.... Sounds like you have to repair the wires first....

Unsure how the Mack electric shutoffs work. My '97 12v Cummins dodge uses 2 solenoids for fuel shutoff lever: one stronger relay kicks it "on" momentarily, then a weaker solenoid kicks on and "holds" the shutoff valve in the "run" position... When you shut the truck off the solenoid powers off and is spring loaded to shut off the lever. A failing shutoff solenoid can cause the truck to shut off unexpectedly. Previous owner of my dodge disconnected the solenoid til he got around to replacing it. He had to reach around and flip the shutoff lever to start/stop it.

Our '79 used to run on 4 - 6volt batteries, 2 in series on each side, and each side in parallel to each other, yielding 12 volts... Now we just run 3 - 12 volt batteries as they're easier to come by. Thank God I've never had to deal with a 12/24volt system.

My 79 is lap only. Never had a problem with cops.

I flipped them around, they're both single steps.

One is longer than the other.

I have heard that sometimes the foil from an additive bottle gets into the fuel tank and will clog the fuel suction line intermittently...

I've got 2 square tanks from a 1976 U model you're welcome to. I'm just down 309 in Chalfont PA.

Only reason I knew right away it happened was my dad says he did it once upon a time. Otherwise I would have been scratching my head as to why the 2 stick R made it go forward and D made it go backwards! 10 years later and the truck still runs like a Mack.

We've all done stupid stuff. I managed to get our 1979 R686 Maxidyne engine to run backwards, lol... You can stall the engine out in such a way that the crankshaft "bounces" in the opposite direction and the engine will run backwards.... A quick pull on the stop knob, bump the key, and you're back up and running!

Change your fuel filters? Check suction lines for collapsing?

Lol sounds miserable! Clean your crankcase vent filter. I'm assuming the mp series engines use one. The ETechs use a steel wool donut that clogs up over time. If your vent is plugged up it'll pressurize the crankcase. Even a tiny bit of pressure will cause things to leak.