peteslagel Posted June 12, 2008 Share Posted June 12, 2008 I have seen Mack shifting plates for Quadraplex transmission, in B model cabs, that have both 14 speed and 18 speed. Is there a difference in the transmission? Does anyone have a complete list of the Quadraplex gear ratios? Quote Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/ Share on other sites More sharing options...
Packer Posted June 12, 2008 Share Posted June 12, 2008 Go to oldmacksrus.com under links.More info there than you can stand!Endines, transmissions, cabs - - - Good stuff!!!Packer Quote Keep a clutchin' Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/#findComment-19710 Share on other sites More sharing options...
Freightrain Posted June 13, 2008 Share Posted June 13, 2008 I'm gunno say the 14 spd version is the Double overdrive, so you leave out a few shifts in 5th.Check the website as it has all the gear ratios. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/#findComment-19726 Share on other sites More sharing options...
peteslagel Posted June 13, 2008 Author Share Posted June 13, 2008 Great, I found it on the old site under "Info" or else "Links" and then B "Model Info". Very interesting. Tom Gannaway did a great job collecting that list.It looks like lo-lo is only usable in 1st and 2nd in the 72 series transmissions. The TRQ-72 looks like a direct main box with 15 speeds and two low holes.The TRQ-720/7210/7220 all look like a 13 speed double over with 2 "useable" low holes.I still can't work out the math for 14 and 18, but there must be some logic behind it.Thanks for the help.Pete Quote Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/#findComment-19728 Share on other sites More sharing options...
Packer Posted June 17, 2008 Share Posted June 17, 2008 The 18 speed goes from 4-Hi to 5-Hi (double overdrive)There are only about 12-13 useful gears buy the time you skip one or two here and there.The math doesn't add up but the old 'B' will get-R-none.!-Lo-Lo1lo 1direct1-hi2-lo2dir2-hi3lo3dir3-hi4lo4dr4Hi5HiThat's 14 gears and that's makeing every shift.Skip 1direct and you got 13.That'a about all you need.Course differant conditions may dictate something a little differant.Empty and bob-tail you can skip a couple more.Packer Quote Keep a clutchin' Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/#findComment-19808 Share on other sites More sharing options...
JD 5020 Posted November 18, 2008 Share Posted November 18, 2008 (edited) I too was playing around with gears and ratios. Here is all I could really get out of a TRQ-7220 quadbox. 15 5HS 0.7014 4HS 0.8413 4D 1.0012 4LS 1.2011 3HS 1.4710 3D 1.769 3LS 2.108 2HS 2.617 2D 3.136 2LS 3.745 1HS 4.554 1D 5.453 1LS 6.522 2LL 7.921 1LL 13.80 Edited November 18, 2008 by JD 5020 Quote Link to comment https://www.bigmacktrucks.com/topic/3852-14sp-vs-18sp-quadraplex/#findComment-24476 Share on other sites More sharing options...
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