Mack Quadruplex diagramatic

Thanks Kav,
If the front section was a bit dodgy, you would maybe wonder as to the wisdom of shovelling the torque of the V8 Maxidyne into it ? The one I wasn't familiar with was the 6 cylinder Maxidyne 300, knew the 237 turbo and the 285 with the air-to-air cooling, Maynes went firstly to the 320 Thermodynes and them the 350 four valves. We seemed to get a reasonably good run out of the 285 with the 5 speed on line haul. Thanks for the info, Dave

Was ginning around with some old figures on the different transmission ratios available yonks ago and found this.
Not sure if it is Mack, may even be Fuller, Brown or Clarke.
What it was, a 10 speed twin sticker with a direct and overdrive on the second stick.
The main 5 speed ALSO had an overdrive in it (5th) which had me puzzled a bit at first, until I went back over these posts.
There were two different sets of ratios given in the main,5.8:1--2.85--1.65--1.00 and 0.8oo:1

Look at the gap between Ist and 2nd!

The alternative ratios were as follows....... 5.478--3.075--1.637--1.00--0.749:1
If you multiply the ratios in the rear section of the box (both sets the same, 1.00:1 and 0.804), you get a pretty good idea of the range spread, second one I'd imagine a lot more user friendly.

I would guess this would be used mainly in off highway applications, although did see somewhere here of the B models also having overdrive in the main AS WELL as another overdrive in the auxilliary, or compound.
Must have had an extremely high crown wheel(s) to pinion count, because DOUBLE overdrive would have been 0.643 OR 0.602:1 respectively.

Recalling that some of this gear would have had a road speed of something in the vicinity of 25--35 MPH, running on 24 inch tyres, you get a bit of an idea

Read somewhere that both some of the modern 18 speed as well as the 13 speed Roadrangers ran double overdrives around the same ratios, but they were also running very high horsepower compared to a few years ago.
Just thought there were some interesting ratios available.
I could be completely off track here, I always considered that in the cases of compound (or auxilliary) transmissions, once you get below around the 0.80:1 ratio in a final output, you either spent a lot of time running one way empty or you had horsepower to burn.
Which brings me back to the Mack Quadreplex boxes with dual overdrives. Even if they had wall climbing, stump pulling ratios, they were only running around with 180 odd horsepower, or maybe 210? Maybe thats why a lot of blokes preferred just having the 5th speed as direct and the overdrive ratio in the compound?
Wouldn't be loading the main box up as much (being a straight through drive in direct) and possibly a better spread of ratios in the lower gears.
What do the gear-heads think?
Dave_64

The Quadruplex box (and duplex and triplex) was a single countershaft box......all the pics shown are the triple countershaft box......a completely different thing........The old single countershaft quad box could take the power of the old Cummins motors in the bigger models like the B83......most of these were around 350Hp......there was also a Mack V8 of 864cu in,and 250hp.