dek1581 Posted August 12, 2015 Share Posted August 12, 2015 I was recently looking at old brochures on f models and although they had maxidyne 675 and 676 paired with maxitorque 5-speed, the mack etaz 673a (300 plus) was paired with 10-speeds or better. based on the horsepower and torque ratings and rpms, it seems like the 300+ was a higher revving engine(correct me if I'm wrong). why was this and is it possible to pair the 300+ with a maxitorque 5-speed and if not, why? Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/ Share on other sites More sharing options...
alex g Posted August 12, 2015 Share Posted August 12, 2015 I own one so it must be trueSent from my SM-G386W using Tapatalk 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-299915 Share on other sites More sharing options...
kscarbel2 Posted August 12, 2015 Share Posted August 12, 2015 By intention, the 300 Plus was designed for a multi-speed transmission (9 or more speeds). But having said that, we had customers pair them with Maxitorque 5-speeds and drive them thousands of miles, completely satisfied with performance, fuel economy, ect.Operators do need to watch their pyrometers in "extreme" operating conditions. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-299916 Share on other sites More sharing options...
dek1581 Posted August 13, 2015 Author Share Posted August 13, 2015 is the ETAZ 673A the 4-valve upgrade that was introduced around 1984 or was it earlier in a 2-valve version? Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-299988 Share on other sites More sharing options...
b61mack Posted August 13, 2015 Share Posted August 13, 2015 2 valve, don't think they made a 4 valve ETAZ 673 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300016 Share on other sites More sharing options...
chief doug Posted August 13, 2015 Share Posted August 13, 2015 i used to repower 237's with 300's. mack said that was the highest hp to put on a 5 speed Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300019 Share on other sites More sharing options...
Joe Ditchkus Posted August 13, 2015 Share Posted August 13, 2015 I do not believe it is the torque range lacking on a Maxitorque 5 speed trans it is the amount of gears when used with a ETAZ 673 that was designed for multi speed trans such as 9,10,12,13 0r 15 speed. The ETAZ 673 was not a constant torque engine as the 237 and 300 Maxidyne was. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300020 Share on other sites More sharing options...
Superdog Posted August 13, 2015 Share Posted August 13, 2015 i used to repower 237's with 300's. mack said that was the highest hp to put on a 5 speedthere were 2 versions of the Maxitorque 5 speed,the ones the put in 6 cylinder trucks were the TRL1076 and TRL1078 which they put behind the V8 Maxidynes. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300033 Share on other sites More sharing options...
Outbehindthebarn Posted August 14, 2015 Share Posted August 14, 2015 One on ebay:http://www.ebay.com/itm/1981-Mack-Superliner-30-ton-wrecker-/221850037193?forcerrptr=true&hash=item33a74aebc9&item=221850037193 Quote Fun is what they fine you for!My name is Bob Buckman sir,. . . and I hate truckers. Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300073 Share on other sites More sharing options...
Superdog Posted August 14, 2015 Share Posted August 14, 2015 One on ebay:http://www.ebay.com/itm/1981-Mack-Superliner-30-ton-wrecker-/221850037193?forcerrptr=true&hash=item33a74aebc9&item=221850037193That one is a RWS786LST so it's just a 300,if it had a 300+ it would be a RWS712LST 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300084 Share on other sites More sharing options...
Outbehindthebarn Posted August 14, 2015 Share Posted August 14, 2015 That one is a RWS786LST so it's just a 300,if it had a 300+ it would be a RWS712LSTEveryone wants their 300 to be a Plus+... 1 Quote Fun is what they fine you for!My name is Bob Buckman sir,. . . and I hate truckers. Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300110 Share on other sites More sharing options...
dek1581 Posted August 14, 2015 Author Share Posted August 14, 2015 hey superdog is there a chart somewhere that shows models and cross references with engines and trannys? Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300115 Share on other sites More sharing options...
j hancock Posted August 14, 2015 Share Posted August 14, 2015 Everyone wants their 300 to be a Plus+...Some people have tried to pass off a 237 as a 350 in truck ads.... Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-300127 Share on other sites More sharing options...
david wild Posted August 22, 2015 Share Posted August 22, 2015 I thought that the 300 was a Maxidyne and the 300 + was a Thermodyne, Maxidyne had 5 or 5 with low stick and all Thermodyne has multi gear trans.????? anyway back when we drove them that is how it was explained to us. Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-301033 Share on other sites More sharing options...
b61mack Posted August 23, 2015 Share Posted August 23, 2015 I think if you pull a 300+ down to 1200 rpm with that much fuel the exhaust temp. would be extremely high, I know my 300+ goes up to 1000 degrees when I downshift mine at 1500 rpm. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/41338-anyone-ever-heard-of-mack-300-paired-with-mack-5-speed/#findComment-301066 Share on other sites More sharing options...
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