Twin sticks, lots older than me,? but thats where I came in to trucking,
In 1970, a '68 Pete was still new , and this one had the 4x4, married, progressive.
Progressive ment the same spacing between gears in the brownie,
about 300 rpm's per shift.
The deep under brownie had a low, low in the 1'st position.
To run hard, and "keep up" with the other trucks, you learned to skip gears.
The shifts were? ?1st direct? to? 2ond direct,? then 2ond over, then
let the r's fall enough to pick up 3rd in the main, and direct in the brownie
a split second later. Used both hands. ? ?In a progressive setup? you could then
shift to 4th double under,
once in 4th , in the main, then the shifts were just 300 rpm apart in the brownie,
right on to your next stop light, what a rat race. Double bottom dumps, got paid
a % of the tonnage rate.
After that I got to drive some transfer dumps, and got on some hourly jobs,
better people to work with, no all day racing.
The "married" 4x4 set up that I drove was smoother to shift than the seperate
main and brownie set ups of other trucks I drove.
Then came 13 speeds, and 15 speeds, single stick, with air range splits,
and who needs to have another 1,000 lbs of brownie anyway.
Back before my time, the standard 3 speed brownie was neded to "pick up"
the next gear,? hence the standard 4 x 3.
I have been told that when the diesel first came out, around 1932,
those old fuel pumps needed some fuel going through them all the time,
so out came the 7000 series main box with the lockout for reverse and 5th.
The 5th was a BIG jump from 4th.
So you would run downhill in 5th direct, engine rpms low, on the brakes,
and a light foot on the fuel too.? That kept the pump lubricated.
Years later, I was still using some of those old "7,000' series boxes in the "assembled"
trucks we used to haul gravel and dirt.
A 5 and 3, with the wrong rear end gears, would have a speed of 48 mph
in 4th over, at 2100 rpm,? and the next shift was 5th direct,? about 85mph
at 2100, when you could pick it up.