oifla Posted October 31 Share Posted October 31 Hello all I'm interested in twin stick transmissions. I've done a few searches but I'm not coming up with the info I'm after, thought I would ask you all to see if it's worth chasing this down further (or if its a non-starter). I'm not a Mack guy so pls forgive me if this is a dumb question. In short, I'm interested in finding out if there's a Mack transmission that will work with an engine that requires an SAE 2 bell housing and has overdrive gears. Is there such an animal? Older units and/or twin sticks are fine (wouldn't mind that at all for my application). Thanks O. Quote Link to comment https://www.bigmacktrucks.com/topic/74699-mack-transmission-with-sae-2-bell-housing/ Share on other sites More sharing options...
Joey Mack Posted October 31 Share Posted October 31 what years are you asking about.. mack transmissions that I deal with have a 1 piece front case with a Mack bolt pattern. Eaton and Meritor transmissions require a Mack bell housing. Mack's have the rear engine mounts on the bell housing. with this said, I have never bothered to learn about SAE bell housings, so I will follow this for my own education.. do you have a truck in mind? Model and year?? Quote Link to comment https://www.bigmacktrucks.com/topic/74699-mack-transmission-with-sae-2-bell-housing/#findComment-561095 Share on other sites More sharing options...
steve s. Posted November 1 Share Posted November 1 The short answer is yes. I can offer two examples; I have a B model the was a concrete mixer. The mixer was driven by a flywheel PTO. To make room for the PTO shaft, Mack used a #1 to #2 reducer at the flywheel housing, and a # 2 at the transmission. This truck had a 673 diesel and a double overdrive Quadruplex transmission. I have another transmission kicking around here that is a "baby quad" that came out of a smaller gasoline powered Mack. I think it only has one overdrive, but it will mate up to a # 2 flywheel housing. Steve 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74699-mack-transmission-with-sae-2-bell-housing/#findComment-561158 Share on other sites More sharing options...
oifla Posted November 1 Author Share Posted November 1 (edited) 12 hours ago, steve s. said: The short answer is yes. I can offer two examples; I have a B model the was a concrete mixer. The mixer was driven by a flywheel PTO. To make room for the PTO shaft, Mack used a #1 to #2 reducer at the flywheel housing, and a # 2 at the transmission. This truck had a 673 diesel and a double overdrive Quadruplex transmission. I have another transmission kicking around here that is a "baby quad" that came out of a smaller gasoline powered Mack. I think it only has one overdrive, but it will mate up to a # 2 flywheel housing. Steve Cool. This is what I was looking for. On your recommendation I found this info sheet on the Quadruplex and it seems like it would work except it is so old that I'm not finding much for sale. Are there newer / more recent versions of that transmission? Thanks O. Edited November 1 by oifla Quote Link to comment https://www.bigmacktrucks.com/topic/74699-mack-transmission-with-sae-2-bell-housing/#findComment-561167 Share on other sites More sharing options...
steve s. Posted November 2 Share Posted November 2 The Quadruplex has been out of production for a long time, but there are still a lot of them around. They were most common in B models and early R series trucks. Perhaps the most popular Mack transmissions in those day were the TR 72 or 722 series of 5 speed transmissions. An O suffix would indicate an overdrive in 5th (TR 7220). Any of these five speeds would have a compound gearbox attached. That gearbox would either have 2, 3, or 4 speeds. These were all two stick transmissions with basically 10, 15, or 20 speeds forward. Most had an overdrive in the compound. There were variations with fewer usable gears, but this is the basic rundown on the Duplex, Triplex, and Quadruplex. The clutch housing for an SAE 2 flywheel housing from any one of these transmissions should bolt right up to any other version. The "baby quad" that I have is smaller than the TR 72 series, it is a TR 770 and was most likely used behind a flathead six gas engine. This transmission would be fun behind a 12 valve Cummins or something like that. The Duplex, Triplex, and Quadruplex were found behind the Thermodyne Diesels and large gasoline engines, but they became obsolete with the introduction of more powerful diesels that required fewer gear ratios. What you are working on or trying to accomplish ? Quote Link to comment https://www.bigmacktrucks.com/topic/74699-mack-transmission-with-sae-2-bell-housing/#findComment-561227 Share on other sites More sharing options...
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