Stuck driving 1 OLD truck, help, 66Mack DM800

Check with Mack, they very probably have a listing for that old part.... may even have one in stock. Lots of old Macks still running.

 

Do a google search "Driving a 2 stick Mack." There are some Youtube videos that might be helpful. Most of those older Macks are low rpm engines and shift points are different than a Cummins, Detroit, etc. Shifting with 2 sticks is an adventure. I drove an old B Model Mack with a 9 speed duplex. 5 speed main, 2 speed auxillary, except in high gear you didn't split.

 

Those old Mack engines were made to pull at low rpms. You needed those low gears for pulling out of a sand pit or rock quarry. Its like having one of the old deep reduction transmissions without the luxury of a selector switch. If you ever lugged a cummins like that it would break for sure. I have delivered fuel to a few coal mines where even double low couldn't get you up a hill and the dozer would hook a chain and drag you up the hill.

 

them old macks are hard to kill, i drove a bunch of them my first few years of driving a mixer.

 

If you've replaced the bellcranks and there's no slop in the linkage, the lever on the fuel pump is not in the correct position. It should be splined, take it off and rotate the lever one spline away from full throttle. With the pedal on the floor, the spring on that lever should slightly deflected, i.e., the fuel pump at full travel, the linkage oh so slightly beyond that point.

 

That's a sweet old mack I would love driving it.I learned to drive on a B-Model with a triplex tranny grinding is just part of it may I suggest you check out http://www.bigmacktrucks.com/ lots of guys there that own/restored old Macks I'm in the process of getting 1964 B-model I just bought on the road

 

LMMFAO!!!!!! OLD MACKS FTMFW!!!!!!!

 

HELL YEAH!!!!! Back in 66' truck were......well TRUCKS!!!!! REAL TRUCKS!!!!!!!!!