What a beautity,,,,,

Andnow for some things you may not know about the "chain drive Bulldog Macks".

In addition to the solid rubber tires, the springs were just large blocks of rubber between the frame & axle and the drivers seat was a flat wooden board covered with a 2" layer of horse hair or pig hair matting and covered with leather. If you hit a bump in those trucks it was a bone jarring experience.

They had what we in the trucking industry affectionatle called an "Armstrong Starter" (Insert the crank and use a strong arm to crank her over).

They used the chain drive because they did not have universal joints in those days and the engine had to be installed level because they had no oil pump, instead they used a splash system to lubricate the engine and if the engine had been install at an angle the front cylanders would not get proper lubrication. The engine was under the hood and the transmission was under the cab, then it had a straight drive shaft to a differential in the frame, where the power went out to the drive sprockets. They then used the chain to transfer the power down to the wheels.

The original chain drives had either a 3.5 or 5 ton load limit, which was remarkably high when you consider most trucks of the day were modified car chassis like the Ford Model T truck with a 700lb limit.

In 1914 Mack introduced the model AB medium duty truck with load capacities of 3.5, 5.5 & 7.5 tons and many hundreds upon hundreds of those trucks were gobbled up by the Military for service in Europe during WW1. Not only did they transport personel and supplies, they were also used to move heavy field artillery. In fact, it was the Brittish "Tommy" soldiers who gave the Mack its nickname of "Bulldog"

In 1918 Mack introduced the model AC with 7.5 or 12 ton capacity and Mack continued building the chain drives right on up to 1938.

In 1973 I was driving a Mack R model pulling a 40' flatbed and hauling steel out of Youngstown, Oh. Our company had a terminal in Dearborn, Michigan and there was a local driver out of that terminal that drove a 1938 Mack model AC with a flat bed, and he pulled a 4 wheel wagon type trailer behind it. He would load 12 tons on the truck and another ten or twelve on the trailer and once he got out on the highway he could easily maintain 60mph. Normally he only ran short haul stuff in the Detroit Metro area, but two or three times a week he would take a load to American Motors in Toledo, Ohio or to the GM plants at Ipsilanti & Flint,Mich.

I was stuck laid over in Detroit once and he had a short trip down to Toledo and back so I rode along. On the way back he let me drive it. To my surprise, he had the same 15speed "tri-plex" transmission that I had in the new Mack R model. A tri-plex is actually two transmissions in one, with two separate gear shifters. The front (main transmission) had 5 gears and the rear one has 3 gears.

You begin with both transmissions in number 1 and as you progress you shift the back transmission through 2 $ 3, then you shift the main up to #2 and the auxiliary back to 1, and reapet the 1,2,3, and continue that process until you get the main up to 5. To shift you hold the main shifter in your left hand and the auxiliary shifter in your right hand while steering by pressing your belly against the stearing wheel...LOL, Oh yes, and don't forget, your doing all that while double clutching.

Mack also made a lot of firetrucks, and they built the first hook&ladder trucks for a city in NJ.

The city of Holyoke, Mass, which is right next to our town had a Mack chain drive hook and ladder truck that they used right up into the late 70's until the got one of the modern snorkle trucks.

You mentioned a lot that I did not know about that truck, one being the engine lubrication system.

Model A Fords also used a combination splash and oil pump lub system. The Model As had an oil pump, but it did not directly lub the crank throws. The oil pump fed the cam shaft and cam lobes, There were trays under each rod end and the rod caps had a dipper. Excess oil spilled over into these trays and the rod dipper swept through a tray splashing oil into a hole in the bottom of the rod cap. This oiled the crank throw. I can see why these engines were slow speed engine.

About every 25,000 to 35,000 miles, new rings were needed on the pistons. This required removing the rods. Woe betide anyone who put the caps on backward with the dipper pointing the wrong way. The caps would fit either way. An engine with a cap or caps installed backward would be destroyed in about 30 minutes.

This lub arrangement handicapped this engine for racing. If you continuously drove the car in a turn in a particular direction, it would sling the oil out of the rod trays and starve the lower end of lubrication.