Mack Technician

PAI industries is an aftermarket for Mack. They own some of the Mack intellectual property rights and build to spec. They usually cost about 25-30% less, but not always. If you have the heads off it’s easy to check or replace H-Rings. Depth and alignment checking them is sufficient. If your feeling a little paranoid you could replace the H-ring on your failed hole. Also check condition of guide pins for the EUP rollers. Do you own an H-Ring installation tool?

Since it’s not a ceramic lifter cam I’d do all EUP and valve lifters. Mack doesn’t sell a kit, PAI does. Pay closer attention to the H ring on failed lifter that it’s mount depth has not changed from others or that it’s turned. You’d get a repeat failure.

I’d do per FJH recommendation and if nothing else is found install (solder) a 1K ohm resistor in the intake sensor line at the sensor. It will change your emissions slightly, but eliminate the stumble and won’t hurt (possibly improve) performance.

Yeah, that’s gotta be bending the block and bouncing the heads?

Radiator shops here won’t touch them. If any part is plastic composite they tell you to pitch them. Don’t imagine DEF “tank thaw” coolant matters right now, but, in terms of internal corrosion blockage.......a clogged capillary means a clogging artery.

Unitized hub........what did you do to it?????

If it doesn't reseal, and its not a sensor on the opposite side, punch a hole and run it though to its mate. Easier that replacement of bulkhead.

Remake with Mazda and a Volvo?! Please don’t make me watch the part where Jerry is resting his head on Burt’s hairy chest.

Swapping thoughts with a well established heavy haul member today about adding an AI460 to his fleet of pavement crackers. Looking forward...He wants to camshaft swap up front. Jump in anyone who has cam swapped a 460, but I’m advising him there’s no great advantage. Mack didn’t/couldn’t afford to/ failed to build a variable exhaust restriction to make the AI engine NOx reduction work at all RPM’s. Instead they built a simple, logic free, fixed restriction that works in one RPM range. At low RPM and low fuel delivery rate there isn’t enough flow back pressure to make the AI fixed restriction work properly, so Mack lowered fuel delivery to lower exhaust ppm at low RPM. Low end torque disappeared. If Mack had designed a variable restriction exhaust they could have choked the flow at low RPM, created back pressure, cooled the burn and reduced NOx @ low RPM. They could have delivered more fuel on low end with a variable restriction and built torque. Any fixed restriction has a pressure delta curve, IOW the more you try to force through a fixed restriction the higher the back pressure. Low RPM, Low flow volume, low back pressure, higher NOx, reduced fuel delivery. No torque and horsepower. High RPM, high exhaust flow, high back pressure, lower NOx, increased fuel delivery. Enough horsepower and torque but overconsumption of fuel due to inefficient, uncooled, EGR back flow. The stock granites get 4 MPG, so plenty of fuel is flowing out at working RPM range, but with a poor return. With nothing else considered......you have a fuel system that delivers too little fuel at low RPM and too much at high RPM. The product of catering fuel delivery to match a fixed restriction rather than varying the restriction to cater to the needed fuel delivery. Once modified.......Too much fuel is making lots of heat and lots of power when running more clean air and less scavenged EGR gas. Everybody notices the pyro operating range is elevated after the upgrades. Flow injectors fix the low RPM (low fuel) delivery issue. Flow injectors also increase an already high output of fuel at full governed RPM. That generates your higher torque/HP return, higher NOx and higher pyro. You can back off the accelerator now since your fuel is giving a power return and MPG increases. You can use the extra top end when needed as long as you manage the pyro. Disclaimer.... With the current arrangement you have sufficient power and a manageable creep on the pyro. Some bump scavenging is likely still occurring (impossible to know how much) and lowering the combustion temp. If the residual scavenge is completely eliminated (by AC cam swap) with this set-up it’s possible to see a rise in pyro beyond the common, manageable, 900F. If little or no bump scavenging is occurring(with the original camshaft), because of our restriction elimination, a bump-less AC cam wouldn’t add performance and could drive more pyro temp....with this set-up. There could be a combination of air and fuel that favors the AC camshaft plus manages heat, however I’m not convinced it would deliver more to the wheels.

I say test, verify blow-by and do an in-frame as necessary. Check for critical stuff that will ruin you again, like air intake leaks from filter housing to turbo causing dusting of sleeves. IMO.... A little hot leakage oil will eat a bite of whatever rubber it lands on then hangout and turn to black dust cake and protect surrounding metal from road salt for the next year..... A constant stream of hot leakage oil will turn your truck into a rubber buffet line, destroy harness wires, Make trans mount rubbers into gummy penguins, turn brake hoses to black licorice and when you rake your finger nails across your rear air bags you'll be leaving grooves.

Click on above link....

Build a manometer and see how many inches of blowby you have.

That’s nuts! Tough enough to disassemble the thing, now deal with all that counterweight baggage.

There’s more than just lines in retro kit. You need bulkhead passages, flow checks, etc.

No, unfortunately. A reverse engineered ASET AI is the closest you’ll get to your engine with a great brake.

Truth be told.......Until Powerleash came on the scene Mack had never had a really great engine brake.

Crank bearings are = or < critical than camshaft bearings in capturing the oil drop-out. Line kits help, it’s not a waste of time. Update Jakes install externals (lines) w/flow check high volume oil pump p1 bearings on mains new cam bearings if all else fails.

Mr.Carter is 94 years old gentlemen. Let’s make sure we give him the respect due to our elder and a former president of this great nation. Personally, I’m perplexed and fascinated that in the final chapter of his life he finds himself pondering the gear mesh requirements of a T3 Mack transmission. If I had to guess I’d have thought he would be wondering why there are “Peanuts” in the Mack power dividers.....being at heart a former peanut farmer? While Barry Obama is smoking pot and mowing down Twink’s this old Blue Dog Democrat is expanding, bravo Mr. President, BRAVO!

It loses oil pressure/flow to actuate jakes in lower RPM because of oil not making it to engine top with sufficient volume and pressure. What do you want to know about? Installation of kit? DIY?

Or worse.....

Yup, pretty cool little marks Mr. President.

Years back they did a sting operation in the county south of us. They waited at a Livestock auction house till the lot was full then started busting farmers. Most farms have a diesel pulling the livestock transport trailers. Not too many farm diesel pickups without red fuel in them prior to it. Then again not too many gasoline pickups on the farm without red fuel (doctored up on Marvel Mystery Oil). They all seem to have a jug. Farmer took me out in his Piper Cub one day and before we left he was putting a few spoonful in each tank for good luck. Still alive so...………..its a marvel?

Failed pocket bearing at union point of main shafts? In my mind that could go elliptical on you.

I wanted to list Sparksracing's (above) comments. He burned out an AI manifold and needed to replace it so he put the E-Tech manifold on his Aset and ran all original parts in tandem with a Programmer (he said Pittsburgh brand). The transition of surface mates can't be smooth, but its a mate. Right off the line he blew his tube boot off and the thing went to smoke, hence the black tar seeping out the gasket. He got things straightened out and from his observation it sounds like the manifold turned him from a 460 Econodyne into a 460 Maxidyne. First AMI460? Ok i have re-tested and all looks ok. No more slobber and normal black smoke, but more than before. The truck runs good for the moment, the only difference. I think is the turbo boosts a little bit slower than before. Before i would boost up to 32 psi now it takes longer to get it, but the truck has more power, it’s strange. I think all is ok. I think when the boot kicked off the engine was not breathing and a little bit of engine oil was go into the exhaust and caused slobber, cause now all is ok . Today it’s too hot 42 degrees outside and the pyro looks like normal, temps 8-900f, but when I let off the fuel pedal the pyros going down more fast than before. I found it more normal, it’s like my Peterbilt. thank you so much

Paul, don't get uncomfortable or weird about this. You seem like a cool guy with trucks and guns. Conservative is a big plus. My mom is a relatively young widow. Guarantee she has better dating etiquette than the chubby quadruped and she's never tried Moxie.