fundadtn

My FIRST suggestion is to take the air cleaners out and try it. If that clears up the problem than you know what caused it. When I was in the trucking business I had more than one shop try to sell me injectors, and turbochargers in similar problems, and sometimes it was an injector or turbo, but pretty rarely, because I watched the exhaust stacks and other symptomatic areas when the trucks were on my yard. An injector should smoke all the time,,, just like a turbocharger would. If the air cleaners don't fix the problem, check the boost pressure line going from the intake manifold to the pump. When the boost pressure is low, it will sometimes allow more fuel into the injectors. Likewise when the boost (manifold pressure) pressure is high, it will automatically decrease the amount of fuel flow through the pump. Hope this helps. Dan.

There were several types of "TWO STICK" transmissions. After the Maxidyne engine came out, with the 5 speed transmission, Mack also made what was known as an extended range transmission, that did have 2 gear shifts, but is not anywhere near the same as the old original 2 stick transmissions. The Duplex was essentially a 10 speed tranny with a 5 speed main box, and a 2 speed auxilliary. For each gear on the main box, you split it with the auxilliary transmission. So each MB, gear was divided into 2 steps. The triplex had a 3 speed auxilliary, and a quadraplex had a 4 speed auxilliary. With the Quadraplex, when you upshifted the main, you brought the aux immediately back to 2nd, if you brought it back to low/1st then your speed ratio was the same as the previous MB gear in high on the aux. THIS CAME IN HANDY WHEN YOU WERE PULLING A HEAVY LOAD UP A HILL FROM A START AT THE BOTTOM. For the "most part" unless you were really havily loaded, you started off in 2nd on the MB, and 1st on the Aux. You progressed through the aux to 4th, and then the next shift, you shifted to 3rd on the MB, and then brought the aux immediately back to 2nd. Then you upshifted to 3rd aux, and then 4th aux, and then the MB to 4th, and the aux back to 2nd. Down shifting was the opposite. If you were really havily loaded or in soft dirt, you started off in 1st MB, and 1st in the aux. (being really easy on the clutch to keep from throwing a U=joint, or wrinkling the drive line.) There are some videos on youtube if you want to see how the 2 stick was progressively shifted. I also created a visual video demonstrating how to shift a quadraplex. these types of transmission were primarily designed for the old gasoline and early thermodyne engines, with low torque factors. If you try to use one behind a maxidyne or later variant engines, it will take out the bearings in the trans... pretty quickly, and I have heard it will break the gears, so I wouldn't recommend using one with the high torque engines. I hope this helps you. Dan.