Mack T2060 6 speed

TATRA ;yes ,you are correct it did have a different shift pattern compared to a normal duplex .i did have a shift pattern plate ,i'll have a look in amongst my junk to see if i still have it. steve

is there any easy way to distinguish between the Duplex, Triplex and Quadraplex just looking at the box?

Tatra The duplex triplex compound box (the back bit)
is shorter than the quad.......

My old b model (673T) had an under/over box in it (Allison) it was easy to pick 'cause it had a short jack shaft between the boxes and the joey stick was on the passenger side like a quad. I later drove one of those B49's?? (about the same hp as a perkins :) it had an under/over in it but it was like the duplex, the stick on the drivers side.
Was tipping a load of sand one day in a maxidyne R model, got the trailer right up....nothing.....by the time I disengaged the PTO, and got the box back into 1st to give 'er a shunt... the bloody thing fell over, PM stayed upright it ripped the mounts off the skidplate and didn't bend the hoist, mind you I needed a change of undies.

TATRA
the duplex box

The triplex box

The quaduplex box
the front 5 speed is all the same
the compound gets longer

Geez they make it bloody complicated eh...
I was going to ask the same as Tatra- is a duplex box really the same as the 6 speed we are talking about here?
From my memory you could spit the duplex hi lo through evey gear (not necessarily quietly though!) so you would use your five main gears, and if you wanted to "halve" each gear you'd use the splt/otherstick, just like driving a quad box?
But doing both hi lo and main range gearchanges at once was always hard work, one hand through the steering wheel etc, and never seemed to go easy. We fouind it was better to shift the main box then change back the splitter..
Interesting thread...good to hear all you old timers stories..
Cheers
Richard
ps my dynatard is hopeless too, I just thought that maybe it was only working on half the cylinders or something dumb like that.. Just another job!

Old Dog,

Thanks for the info. The g/box in question is fitted on a Leyland Hippo behind the original engine. The owner is not sure what he has (he just bought the truck) other than that he's been told it was a Mack 10sp (there are two gear levers). I will try to get more info from him.

The earlier version in the Mack NR (and other 1930s and 1940s Macks) looks a bit different:



Cheers

T

The early Mack 6 speed ( two stick)

Late 6 speed (air shift)