Deere Mack Posted June 27, 2017 Share Posted June 27, 2017 hello, hope everyone's doing well! it's been a while. Looking to either upgrade '79 Mack dump engine or buy another truck. If I upgrade I'm looking at engine (at least 350) , trans and eleminating the old cable leavers and going to air. The truck is in great shape just under powered. 237, two stick 5spd currently. Looking for engine recommendations or used truck recommendations. I know there are a couple years in the early 2000's I've been told to avoid but not sure. I welcome and appreciate everyone's input. Thanks Quote Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 27, 2017 Share Posted June 27, 2017 By the time you've put a later 350+ HP engine, aftercooler, appropriate transmission, etc. into your '79 you may as well just buy the whole donor truck. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 27, 2017 Author Share Posted June 27, 2017 (edited) Hey grrrl, I agree but they are getting hard to find. Maybe I can have one shipped back from Africa..lol Really like the newer Granites. What year is it I need to stir clear from? Edited June 27, 2017 by cdewayne Quote Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 27, 2017 Share Posted June 27, 2017 Actually there's nothing wrong with a '79 RD685S, it was the best truck of it's time. A 237 Maxidyne and a 5+low hole transmission works great at straight truck weights, but 1979 was the era of the 55 MPH speed limit, so at best it has maybe 3.90 gears and a top end of 63 MPH at a screaming 2100 RPMs. It's unlikely to have even basic safety equipment like ABS brakes, never mind a cab that meets ECE rollover standards and traction control. But if that '79 fits your needs, great! But if you need a truck that will cruise at 65 or safely bobtail on ice and snow, better to start with one specced for that rather than try to extensively modify an older one. Quote Link to comment Share on other sites More sharing options...
41180 Posted June 27, 2017 Share Posted June 27, 2017 IF it was me I'd buy a mid to late 90s RD or CL with a e7 350 non computer .if you prefer or 427 -454-460 electronic. If you get into the granites I'd try to find a 02 or 03 without the AI engine. If you go newer I've heard good things about the early mp7 model year 06 and 07 engines with out the dpf, def, hope this helps.the 04 thru 07 granites with the AI engine are ok bUT are known to be underpowered unless you modify them. Quote Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 27, 2017 Share Posted June 27, 2017 I'd avoid the 2007 to 2009s because of the half assed emissions system, and if you can afford a used 2010 or later dump you may as well buy new. I like the first few generations of electronic Mack engines which have a lot of benefits like cruise control and easier cold starting without the hassles of the newer electronic controls. I live in the land of ice and snow so at least ABS is a must, especially on a tractor. So my favorites would be early 90s through 2006. Quote Link to comment Share on other sites More sharing options...
tjc transport Posted June 27, 2017 Share Posted June 27, 2017 (edited) i ran a 05 granite triaxle with the 427 an 8ll trans for two years. great truck, and it would outrun the 05 kenworth T800 with 470HP C13 and 8ll trans. only issue with the granite was highway gears. it would do 90+ on the road, but was no good offroad. i would not go any newer than 05 if replacing. if you repower, you will love the way the truck runs with a 4 valve 350 or 400 with a 8ll trans. Edited June 27, 2017 by tjc transport Quote when you are up to your armpits in alligators, it is hard to remember you only came in to drain the swamp.. Link to comment Share on other sites More sharing options...
41180 Posted June 28, 2017 Share Posted June 28, 2017 41 minutes ago, tjc transport said: i ran a 05 granite triaxle with the 427 an 8ll trans for two years. great truck, and it would outrun the 05 kenworth T800 with 470HP C13 and 8ll trans. only issue with the granite was highway gears. it would do 90+ on the road, but was no good offroad. i would not go any newer than 05 if replacing. if you repower, you will love the way the truck runs with a 4 valve 350 or 400 with a 8ll trans. I had always heard the 04 thru 07 granites with the AI motors were under performers power wise but reliable. I never drove one so I was going on here say. My friend is looking at buying a 06 that was a 370 but turned up to 427 now. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 28, 2017 Author Share Posted June 28, 2017 The 79 has good specs, 4.64, 44k rears, 18k fronts. All original truck except engine, originally a 300+. The 237 worked fine making short runs from the pit and site work, but it just doesn't make the cut on longer hauls and the hilly back roads. If I just upgraded engine and kept the trans, could I tell a big difference? Quote Link to comment Share on other sites More sharing options...
j hancock Posted June 28, 2017 Share Posted June 28, 2017 More HP in your existing chassis will be quicker to accelerate and feel better in hilly terrain but it won't be much "faster" on long hauls. More MPH for long hauls will need different gears or OD trans. Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 28, 2017 Share Posted June 28, 2017 If you've got a 5 speed Maxitorque in there, you need a Maxidyne engine. If it had a 300+ initially and the intercooler and plumbing is still there, hopefully it will match up with a 285 HP Maxidyne. 300 and higher HP Maxidynes used a front mounted air to air intercooler and that didn't come along until the mid 80s. Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted June 28, 2017 Share Posted June 28, 2017 If you keep the 5 speed you are limited to Maxidynes...highest HP is 300. and it will need a front mount cooler If you change the engine to say a E7 350 or 400 you will need a trans with 8 or more speeds.( 8LL, 10,12,13,18 speed) and a front mount cooler Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 28, 2017 Author Share Posted June 28, 2017 (edited) It's got the TRXL107, I thinks it's actually called a 6sp, I call it a 5spd. No inter-cooler or plumbing. The truck has a 23yd bed, with the 3rd down I usually leave the quarry at 81k +/-. It really gets a work out when I'm loaded..lol But it's never failed! Edited June 28, 2017 by cdewayne Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 28, 2017 Author Share Posted June 28, 2017 I'm trying to talk myself into a newer truck and keep old faithful for back up and site work. The engines are getting hard to find around here and the trans are very expensive and hard to find too. Quote Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 28, 2017 Share Posted June 28, 2017 81k pounds is a lot for a 237, I ran 85k pounds with a 237 once, started the load fine but even a barely discernible upgrade pulled it down to 45 MPH. I suspect you're having a hard time finding used parts because recyclers tend to crush stuff that's 20+ years old because there's so few 20+ year old vehicles left to need parts. Quote Link to comment Share on other sites More sharing options...
Timmyb Posted June 28, 2017 Share Posted June 28, 2017 If you find a truck your really keen on, it's worth getting a professional look over it. My brother was looking at a truck, looked great and was right spec. Cummins and Kenworth looked over it, they told him litres of fuel burned, done a blow by test and found a quite a few little things wrong with it. Helps to know exactly what you have, and some bargaining power to get a better price. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 28, 2017 Author Share Posted June 28, 2017 I appreciate everyone's opinion and advice. I'll keep you posted. Talking to a couple people about engines now and might get around to looking at a few trucks soon. Thanks again, you guys always come through when needed! Quote Link to comment Share on other sites More sharing options...
68-f-model Posted June 28, 2017 Share Posted June 28, 2017 (edited) https://huntsville.craigslist.org/cto/6179919373.html Pull the 300 and put it in your 79. Then put the 237 in the smaller dump and presto more power and a back up/smaller second truck. then again I am a sucker for a project. Edited June 28, 2017 by 68-f-model 2 Quote Link to comment Share on other sites More sharing options...
TeamsterGrrrl Posted June 28, 2017 Share Posted June 28, 2017 Looks like another 237 that got a "virtual upgrade" to a 300 when it came time to sell it. Described as a '68 when the Maxidyne 6 didn't get upgraded to 285 HP until '73 and didn't become a full 300 HP until the early 80s. 300 would have a front of radiator aftercooler, this one doesn't even have the 285 HP Maxidyne's engine mounted aftercooler. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 29, 2017 Author Share Posted June 29, 2017 More great info, thanks again! Quote Link to comment Share on other sites More sharing options...
Maddog13407 Posted June 29, 2017 Share Posted June 29, 2017 agree, thats another 237. everyone advertises them as 300's Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted June 30, 2017 Author Share Posted June 30, 2017 23 hours ago, Maddog13407 said: agree, thats another 237. everyone advertises them as 300's yeah, no kidding. I got schooled quick on that one...lol Looking at a donor truck. CH613 same as my lowboy truck. mechanical E7 427, guy says he thinks it's a 9 speed?? should know for sure on that tomorrow. Question is will it bolt right up to engine mounts or should I expect some mods? Quote Link to comment Share on other sites More sharing options...
Timmyb Posted June 30, 2017 Share Posted June 30, 2017 I think the front engine mount is different from e6 to e7. Or so I was told. Quote Link to comment Share on other sites More sharing options...
bts-4120 Posted July 1, 2017 Share Posted July 1, 2017 mack made a 350 2v with tip turbine cooling that would be the highest hp available with out a front air to air had one in a 1982 dm sx was a performer Quote Link to comment Share on other sites More sharing options...
Timmyb Posted July 2, 2017 Share Posted July 2, 2017 12 hours ago, bts-4120 said: mack made a 350 2v with tip turbine cooling that would be the highest hp available with out a front air to air had one in a 1982 dm sx was a performer Would any performance be gained from going to a chassis mounted air to air intercooler? I was told maybe 10-15hp. Any truth to that? Quote Link to comment Share on other sites More sharing options...
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