Mackpro

Make sure you get the good oil/heat resistant gray wire ties for under the valve cover and around the turbo. Make sure you keep the harness away from the timing gears under the valve cover at the back as well

It was real screwy trying to navigate the older trucks in Impact parts screen. When I clicked on the axle beam it went to a page with 2 choices and either path I took gave different axle beam arrangments. However the leaf spring results were the same regardless. Hopefully someone else here who's at a dealership and have a try at it.

Turbo or turbo actuator could be an issue. We have had turbos cause no start issuses. Dealer should have done turbo function test and looked at actuator motor effort. If it was high then turbo and actuator should be looked at.

The truck is still listed in the Mack parts system. It was built on 11-29-1984. The parts break down for the front axle beam gives 2 choices of what front beam was on it. Either a FAW 536C or a FAW 537C. When I pulled up the leaf springs assembly it shows a 3 leaf 2QK3345 springs.

I see the problem! Your steering gear box is on the wrong side of the frame! LOL. Just kidding! We always set up the pump timing 1 to 1.5 degrees above what ever it say on the valve cover using the A/B light that plug into the side of the injection pump. Any higher that 1.5 degrees we found that the engine will over heat in the summer months.

It takes alot or work , In two years I've worn 3 high speed buffers polishing my tri-toon. Then its a constant job to keep it looking good. I spend about an hour a side every weekend in the summer. I use White Diamond polish then wash the haze off with a rag soaked in mineral sprits and then wash with soap and water before anything dries. .

Poor cab ground, Check the cab ground breaker on the firewall for loose wires. You can test by using jumper cables from the negitive on the batteries to a good grounging spot on the cab

I vote low boost pressure as well. On those older engines, does the air compressor get its fresh air from the intake manifold like most of the ETECH's ? If so , the line coming off the intake manifold to the air compressor could have been left off.

I agree Dave, I will be donating my wealth this weekend as well. One dollar at a time!

Lots of threads on here about the AI engine " low power complaints ". We always start with , check fuel pressure, test drive and check boost pressure and leak test intake system. Ajust valves and replace rocker arm hold down bolts. Update all software to newest levels "Step 12b". Calibrate throttle pedal. Make sure tire size and rear gear ratio are correct in ECM settings. Check muffler for broken baffles. Check and see if trans has been changed or tires to tall for rear gear axle ratio. 4.42 or 4.64 work best unless your running 22.5 low pros. Return truck to customer and let run a few days and if still underpowered start looking at HP change or different software from Mack. Sometimes their generous and let slip a "hot " file out. Happened to me a month back.

For some reason Mack has been setting the "Min set speed for PTO 0" to 1000 rpm or higher. PTO 0 is what Mack calls the fast idle now. The way Mack sets it now , you have to raise the rpm's up with the pedal then set it with the switches. We always go in and set it to 600 rpm so you can bump the idle up with the switches and never touch the pedal.

Mountain O' Gears.

Bull gear didnt go down on this one . Idler gear that run the fuel supply pump/power steering pump ( called tandem pump by Mack) went bad . Still gotta strip it all down to get it out.

Our clutch jack is broke so Ill be flying with a broken back! LOL

We live in a "disposable society" today. 30-40 years from now, no one will be pulling CHU's out of the weeds to restore like they do B Models now. We have a young boy here that does all the Bull Gears, sadly he was in the middle of a major overhaul so I took the job. Im to old for this sh*t. LOL

We actually have done more bull gear failures on Detroit 60 series than Macks. However at least the gears on the Detroit are in the front and not the back. One of the downfalls of the over head cam engine . I miss the E-Tech's. LOL

There is a 5 year/ 500000 mile warranty on Bull gear failures as well

This was supposed to be fixed by 2012. The failure was due to high oil temp to the gear train, This was fixed by software downloads that opened the oil valve at a lower oil temp so the timing gear bearings didnt get to hot ( All part of the "Clean Idle" crap) The oil filter stand is a maze of thermostats and oil control valves. They improved the bull gear as well. The failures really dropped off after 2012 but still happen , we only do 1 or 2 a year here.

Here are both the service bulletins. I remember doing alot of them. Ill check and see if I can locate the kit if it hasnt been thrown away. Im doing a bull gear failure in a 2014 MP8 right now. I think Id rather be hit in the head by Mike Tyson than do this. MP7 idler gear pinning.pdf MP8 idler gear pinning.pdf

Have you got MP7's or 8"s?

Yes , that is a CCRS injector. Original part number for a 460 HP injector is a 736GB410M. The Reman part number is now 736GB420M3X. Here is a chart I put together for the 350HP and up CCRS engines that shows turbo and injector part numbers scan0325.pdf

If this is in a RD. You might rig up 5" exhaust with a good Walker high flow muffler. I was thinking the RD's had 5" at turbo and necked down to 4" pipe and a 4" in/5" out muffler. Dont know how much it would help but it couldnt hurt.

If its the Behr fan, here is the troubleshooting for it. If on this fan, if it ever locks solid its bad. Also it will never totally freewheel like an air fan clutch. In the bulletin it shows where to put 12 volts and ground to the fan to make it disengage. remember it might take 10 or more minutes to disengage and even longer in cold weather. Also when you run your defroster in cold weather, your AC compressor is engaged. If you have high AC head pressure it could be turning the fan on. sb215024 ASET Behr fan.pdf

Thats good news! Mack uses 2 different part number boost pressure sensors on the ETECH style motors. The early ETECH, the CCRS and the ASET AI use the same sensor. The ASET AC ( EGR cooled 2004 CH/CX and later CXN/CHN ) use a different sensor . They both look exactly the same and the incorrect one can easily be installed . If the wrong one is installed in a AC engine it casuses very low power , check the part # . Also on the 2004 CH and CX with the ASET AC engine , the boost pressure sensor can rub the air filter piping and break the sensor. Add a 45 degree 1/8" pipe fitting to turn the sensor down. Bulletin attached sb273008 2004 Boost pressure sensor.pdf