b61mack Posted August 17, 2008 Share Posted August 17, 2008 i have a TRDL1070 Mack 10 speed transmission i was thinking of putting in my B model behind a 237, i would like to here the pros and cons of the 1070, is it an overdrive and the same transmission as a 12 speed except the extra low gear. is it as good as the 12 speed, you here about the 12 but nobody talks about the TRDL1070. Thanks Ron Quote Link to comment Share on other sites More sharing options...
storkmack Posted August 17, 2008 Share Posted August 17, 2008 My dad had one in a Crusie Liner back in the day. Multi speed reverse, spiltable gears. He really liked it. I haven't seen one since. I think it would be a fine trans for behind 237. Brad Quote Link to comment Share on other sites More sharing options...
GearheadGrrrl Posted August 18, 2008 Share Posted August 18, 2008 The 237, like all Maxidynes, was designed with a broad torque curve so it only needs a wide ratio 5 speed for on highway applications. The 6 speed added one more lower gear for on/off road applications. The 10 and 12 speeds are basicly the wide ration 5 or 6 speed with a second "splitter" feature to "split" each of the 5 or 6 gears, giving a 10 or 12 speed transmission. The 237 like all Maxidynes doesn't absolutely need a 10 or 12 speed transmission, but the extra gears don't hurt and they can add some flexibility. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted August 18, 2008 Share Posted August 18, 2008 The 237, like all Maxidynes, was designed with a broad torque curve so it only needs a wide ratio 5 speed for on highway applications. The 6 speed added one more lower gear for on/off road applications. The 10 and 12 speeds are basicly the wide ration 5 or 6 speed with a second "splitter" feature to "split" each of the 5 or 6 gears, giving a 10 or 12 speed transmission. The 237 like all Maxidynes doesn't absolutely need a 10 or 12 speed transmission, but the extra gears don't hurt and they can add some flexibility. Your right and that is the cadillac of trans if you have a 237 0r 285 engine for as the 12 speed goes. I like it because on a long pull you can cut the rpm back some. Quote glenn akers Link to comment Share on other sites More sharing options...
terry Posted August 19, 2008 Share Posted August 19, 2008 I owned a DM with a 285 turned up and a 12 spd. overdrive with 4.17 rears, absolutly the best combo i ever drove. you could not believe the trucks i could outrun. But it sure liked the fuel if you kept your foot in it. terry Quote Link to comment Share on other sites More sharing options...
b61mack Posted August 23, 2008 Author Share Posted August 23, 2008 The 237, like all Maxidynes, was designed with a broad torque curve so it only needs a wide ratio 5 speed for on highway applications. The 6 speed added one more lower gear for on/off road applications. The 10 and 12 speeds are basicly the wide ration 5 or 6 speed with a second "splitter" feature to "split" each of the 5 or 6 gears, giving a 10 or 12 speed transmission. The 237 like all Maxidynes doesn't absolutely need a 10 or 12 speed transmission, but the extra gears don't hurt and they can add some flexibility.So the 10 and 12 speeds are wide ratio transmission like the 5 speed,you could drive it like a 5 speed then for cruiseing you could use overdrive to lower the RPM. i have 4.17 rears on 20" rubber, anyone no offhand what speed it would run. Thanks Guys Ron Quote Link to comment Share on other sites More sharing options...
Superdog Posted August 23, 2008 Share Posted August 23, 2008 So the 10 and 12 speeds are wide ratio transmission like the 5 speed,you could drive it like a 5 speed then for cruiseing you could use overdrive to lower the RPM. i have 4.17 rears on 20" rubber, anyone no offhand what speed it would run. Thanks Guys RonRoughly 78 mph. Quote Link to comment Share on other sites More sharing options...
dak49 Posted September 9, 2008 Share Posted September 9, 2008 Your right and that is the cadillac of trans if you have a 237 0r 285 engine for as the 12 speed goes. I like it because on a long pull you can cut the rpm back some.I think you could actually get a little better fuel mileage from a 10 or 12 speed by shifting earlier and keeping the engine in the high torque rpm range. I think that's what Mack did with the "Econodyn" engine, they cut the rpm back to 1800 then used a 9 speed or more gears to help keep the engine rpm closer to 1200-1300.One of the problems though was Mack didn't have any real high speed rear gears to get your speed back, hence the overdrive transmissions.I could be wrong about my info, but I'm pretty sure I am close to correct.Have a good dayDak49 Quote Link to comment Share on other sites More sharing options...
ThaddeusW Posted September 10, 2008 Share Posted September 10, 2008 The 237, like all Maxidynes, was designed with a broad torque curve so it only needs a wide ratio 5 speed for on highway applications. The 6 speed added one more lower gear for on/off road applications. The 10 and 12 speeds are basicly the wide ration 5 or 6 speed with a second "splitter" feature to "split" each of the 5 or 6 gears, giving a 10 or 12 speed transmission. The 237 like all Maxidynes doesn't absolutely need a 10 or 12 speed transmission, but the extra gears don't hurt and they can add some flexibility.I read up on this and The 12 speed is indeed the same as 1070 but with the addition of yet another aux section that was either a stick or dash mounted air switch. It gave you two very low gears like a 2 stick 6 speed. You kept the switch/stick in hi for on road stuff and you had 10 forward and 5 reverse gears. Set the switch/stick to lo and you used only first and second for two deep reduction gears. From what I hear its one heck of a big tranny. Quote -Thad What America needs is less bull and more Bulldog! Link to comment Share on other sites More sharing options...
b61mack Posted September 21, 2008 Author Share Posted September 21, 2008 I read up on this and The 12 speed is indeed the same as 1070 but with the addition of yet another aux section that was either a stick or dash mounted air switch. It gave you two very low gears like a 2 stick 6 speed. You kept the switch/stick in hi for on road stuff and you had 10 forward and 5 reverse gears. Set the switch/stick to lo and you used only first and second for two deep reduction gears. From what I hear its one heck of a big tranny.Thanks guys it sounds like a good combo,i have to put a new clutch in so it would be a good time to change the transmission, one more question will the big driveshaft and U joints be too much weight for the rear bearings on the trans. i have 3 of those transmissions and they all take the small driveshaft. Thanks again. Ron Quote Link to comment Share on other sites More sharing options...
MACKS Posted September 21, 2008 Share Posted September 21, 2008 I have two trucks with 12 speeds and they both have the big u joints,just in case you don't know,that tranny comes in overdrive and direct,so make sure you check the numbers on the side of the tranny.Good Luck Quote Link to comment Share on other sites More sharing options...
bulldogbred Posted November 17, 2008 Share Posted November 17, 2008 I have the 12 speed in my 1975 RS700L behind a E7400 Mechanical, and I LOVE IT! I don't think I can tell you how much I like this tranny. We have two RD's one with a 400 and one a 350 both have 8LL's, we also have a CL with a ISX600 and an 18 spd, and I will be honest with you I will take the old R700 any day over the CL, more low end power, and that 12 speed just drives like a Cadillac, once you get rollin you only need to use two gears because like a 5 speed 4th gear is high enough to do 40-45 and low enough to do 30 for rollin into a town. I hardly ever use the Low gear in my 12 speed only when you get in real soft ground when I'm off road. Quote Link to comment Share on other sites More sharing options...
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