14 speed Quadraplex behind end711.

[teched]

Finaly got my parts truck home and of course i want to see if i can get it run.  I didnt have a long enough bar with me so i will have to go back and give it a spin...hopfully.  Anyway i discovered the truck has a 711 backed up bt a 14 speed.  I am not familiar with.  Are they any good? 

[mowerman]

well i have one and the 4th speed direct gear was stripped,they tell me it was a common issue with them,,,,,apparently mainly driver era,,,,but thats after many years,,,im replacing it with a 20 speed ....but yes all mack transmissions are very tough    have a ball,bud...bob

[doubleclutchinweasel]

That is a double-overdrive trans.  Shifting is pretty much the same as an 18-speed version.  Even in the 18, 14 speeds were really about all you could use, anyway.  The 20-speed is a single overdrive, and the sequence is different in high gear.  Somewhere, I have the ratios for that box.  I will try to find them.  The Quadruplex is my all-time favorite Mack transmission.

[doubleclutchinweasel]

Here is some numerical info on the 14-speed gear ratios.  hey really are not that different from the 18-speed.  It's probably called a 14-speed because, if loaded really heavy, you would usually start in Lo-Lo 1st, then go to Lo-Split 1st, then pick up the "normal" sequence.  On occasion, I tried using the Lo-Lo 2nd, then going to Lo-Split 1st, but the road speed was really too low to make that work well.  So, the 18-speeds we had were really "14-speeds", too.  Ignore the "18" on the shift plate.  I didn't have a good picture of a 14-speed plate!

 

[fjh]

You will need every gear ! 🤣I had opportunity to work one of these on a site job for a week ! You really get a work out shifting gears all day! thermal dyne engine ! not to much on power or power band! All I can say it was an experience!!😅 the Note At the bottom of the shift plak there is quite hilarious!  You likely would never get into hi gear except on the down hill!🤣 

Edited August 29, 2022 by fjh

[doubleclutchinweasel]

Most of the time, we only used 7 or 8 gears...even loaded.

[mowerman]

Ya especially taking off empty.. bob

[Mark T]

8 hours ago, fjh said:

You will need every gear ! 🤣I had opportunity to work one of these on a site job for a week ! You really get a work out shifting gears all day! thermal dyne engine ! not to much on power or power band! All I can say it was an experience!!😅 the Note At the bottom of the shift plak there is quite hilarious!  You likely would never get into hi gear except on the down hill!🤣 

F, you'd be surprised. Don't forget, something like that topped out in the low 50 MPH range. True they didn't spend a lot of time in HI gear . At the time though ?  for a dump truck or a mixer (or something like that) they were pretty good at walking around in soft earth with a load on them.  (lol)  What were they ??? 170 HP and like 600 lb/ft of torque in a narrow RPM range ??  In 1960 though.....that was something.

[Freightrain]

5th was OD, so using under or direct in the compound would be slower gears.  Once in 4th Over, 5th was the last gear.

[mechohaulic]

On 8/29/2022 at 9:21 AM, fjh said:

You will need every gear ! 🤣I had opportunity to work one of these on a site job for a week ! You really get a work out shifting gears all day! thermal dyne engine ! not to much on power or power band! All I can say it was an experience!!😅 the Note At the bottom of the shift plak there is quite hilarious!  You likely would never get into hi gear except on the down hill!🤣 

when men were men LOL. didn't need 600 hp or auto trans . didn't haul as many loads either ;; hey can't have everything

[doubleclutchinweasel]

On 8/30/2022 at 10:21 AM, Freightrain said:

5th was OD, so using under or direct in the compound would be slower gears.  Once in 4th Over, 5th was the last gear.

Seems like we've covered this on here before, don't it Larry?!