JoeH

I'm no expert, but I'd be surprised if the beam is shot. The kingpin usually "locks" to the beam on the tapered center section. It's the steering knuckle that rotates on the kingpin and takes the wear. Removal sucks, there's a special + shaped socket for them. Tool also comes with a thread chaser to clean it up before reinstall. My dealership was nice enough to lend me theirs a couple years ago for my '95 RD688S. Disassembly is basically block up axle, remove wheel and brakes, remove cotter pin, remove + nut and top cap, place an old kingpin on top of the kingpin you're trying to remove and beat it with a 6 or 8 lb sledge hammer. It'll drop out eventually. Remove the upper and lower bushings, polish off any burs, install new bushings, thrust bearing, pin, etc. Install + nut and cap, (cap is supposed to get tack welded on so grease pressure doesn't push it off...) The purpose of the + nut is to set the spacing of the steering knuckle in relation to the axle beam. The beam is supposed to "Float" in between the upper and lower knuckle bushings without making contact. Book spec's so many thousandths of an inch of gap. Tools needed: usual wheel/brake tools, + Nut tool kit Big ratchet or gun to spin + Nut Grinder if top cap is tacked on Big sledge hammer and punch Normal hammer and socket or chisel to remove bushings Probably missed a few things...

Mack doesn't make cams for these engines anymore, don't know if PAI does. I think there's a cam shop in the Midwest (berry cams maybe?) That can weld and regrind a bad lobe.

Oil pan and valve covers show you pretty much everything you need to see on an engine. Pull valve covers and check your pushrods and rocker arm, look for a cylinder way out on adjustment. Pull your oil pan to see the condition of the bottom end, look up at the camshaft and check to see if you wiped a lobe off with a broken lifter face.

We had one of our endt676 engines drop a valve seat out on one cylinder once. Hell of a sound. It was fine when I shut the truck off one day, but when I started it up the seat must have dropped in while it was shut off. I kept the piston, it has chunks embedded in the crown. Too cool of a paper weight to pass up!

The reason your mechanic won't do it again is that these engines have a lot of duct work to get to the valve covers. 2 sets of intake pipes, one for intake and one for the tip turbine. They go together like a puzzle. Crankcase breather crossover tube on top of the valve covers, and the valve cover gaskets are a right PITA! Especially if you have a Jake brake. We have had to straighten our valve covers numerous times, we've learned you have to torque them up by the book to keep them from leaking. They deform with the slightest amount of overtorque

ENDT675 is a D for Diesel, T for Turbo, 675 is a 237hp. ENDT676 is similar, but is 283hp and has the Tip Turbine intake air cooler setup. Turbos are different, fueling is different, minor changes to block reinforcements, cylinder head bolts might be different. ENDTB (B means it has dynatard engine brake) is another possible part of the sequence. They are all 672 cubic inch engines, but they upped the last digit as they generated new hp variants.

Yea cng is starting to show up here in the states.

I don't know how anyone can read this and do anything other than cheer.

Let's be honest. Honest politicians are near impossible to find. Yea, trumps an asshole. But an asshole is what we needed. Someone to ground Pelosi's federally funded flight to another country when she was shirking her job. You don't send a "nice guy" to deal with crooks. With basic exceptions of national defense, there's really only one place politicians affect every day Americans, and that's our Wallets. I'll take $2 diesel over the $5.45 we're paying right now.

A lot of these bolts take big torque to tighten.

Trunnion bar on our dm686SX broke probably 8 years ago. Don't remember what all was involved, I just remember the bar was about 3 to 500 lbs of solid steel. When it broke the external trunnion stand brackets sat down on the spring u bolts. I think if I were going to go to the effort of replacing bushings (which I plan to this year on one of my trucks that needs springs) I'd replace the bar as well. I don't think it's too difficult, the rear of the truck frame should get set up on blocking or HD metal sawhorse so that the camelbacks hang. If taking the dump bed off isn't a challenge for you then I'd say that's a prudent safety move that may make access a little easier.

Wrong PTO and hydraulic pump either got ordered or were delivered. Correct ones had to be ordered, looks like beginning of April this thing should be done. Parts were about a 3 week delivery schedule, and they need about a week to install and run QC on the mixer to complete the project.

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....