Was the 5sp Maxitorque transmission used with 300+hp engines?

[Jamaican Bulldog]

I know the legendary 5sp Maxitorque transmission was used in the 237hp and higher output engines, but was it used in engines with more than 300hp such as the  V8 and 350 hp sixes?  Did the  multiple speed transmissions such the 9sp have the  same design concept as the 5sp with high torque rise engines? In other words did the 9sp in higher horsepower engines reduce the need t use 13 or more speed transmissions.

[Maxidyne]

The 5 speed Maxitorque was available and used with the V8 Maxidyne engines. IIRC the later 300 series Maxitorque wasn't built in a 5 speed version, but the 6, 7, 8, etc. speed wide ratio Maxitorques were used with Maxidyne versions of the Mack 12 liter and Volvo based 11 and 13 liter engines.

[kscarbel2]

Was the 5sp Maxitorque transmission used with 300+hp engines?

No. The 300 Plus was design for multi-speed (Eaton) transmissions, typically a 10-speed back then. We knew the 300/5-speed Maxitorque combination was the best (and certainly the envy of the industry). However, some multi-speed transmission customers simply wouldn't bend and give it a try. So creating a multi-speed version of the Maxidyne allowed us to play both sides of the fence (We didn't call the 300 Plus a Maxidyne, because spec-wise it wasn't).

Now, I know customers that put a 5-speed Maxitorque transmission behind a 300 Plus, because the Eaton blew up and they had a used 5-speed on the floor. And I watched those trucks run the road for years. But technically, it was a mismatch.

This all being before CMCAC (Chassis-mounted Charge Air Cooling / intercooler), the 300 had 285hp and the 300 Plus had 315hp. But they performed nose-to-nose.

The Maxidyne Plus (ETAZ-673A) was the first Maxidyne to be painted a color other gold, that being Andes Copper. The 2-valve E6-350(R) was also painted Andes Copper. This color designated engines designed for multi-speed transmissions.

The early 300s, with the scoop in the R-model hood, were the most powerful ever built. They could pull a building off it's foundation and up a hill.

[Lmackattack]

As Ksarbel said .. No, the 300+ (315Hp) did not come factory with a 5 speed behind it.

 

I see many owners and for sale ads comment in error of a 285 or 300 Maxidyne listed as a 300+.  

[Jamaican Bulldog]

Were the twin stick 5sp that was common in DM models the same as the regular 5sp transmission but with a Hi and Lo? Those were indestructible.

[terry]

5 spd. main with a reverse, direct and low on the back box.     terry

[Jamaican Bulldog]

 

On 11/2/2017 at 5:26 AM, terry said:

5 spd. main with a reverse, direct and low on the back box.     terry

Does that mean that the twin stick was actually a 5sp with an auxiliary gear box attached?

 

[Lmackattack]

2 hours ago, Jamaican Bulldog said:

 

Does that mean that the twin stick was actually a 5sp with an auxiliary gear box attached?

 

 There were 2 different versions of 2 stick "5 speeds" The early version had Reverse and 1-5 on the main. the Hi / low was on the aux stick. this was a over drive transmission. The later and more popular was the 2 stick 6 speed direct. it had 1-5 on the main and Low/direct/Reverse on the aux (compound)stick.   both of these boxes had a married aux box bolted to them. 

[mrsmackpaul]

you could buy the V8 Maxidyne 325 hp with a 5 speed and a lot of those had 4 speed spicer box behind those for heavy haulage and road train work 

I guess some Aussies had a chub a thon with quad box and this was similar 
I have been told and have seen 375 V8's with a quad box on road train work and seem to hold up ok not that has anything to do with the question

As another side note I dont think there was any stock standard run of the mill Macks KW Peterbilt Autocar or whites ever sold out here as they were all and still are pretty much custom made for customer 

Paul

[Jamaican Bulldog]

On 11/9/2017 at 12:51 AM, Lmackattack said:

 There were 2 different versions of 2 stick "5 speeds" The early version had Reverse and 1-5 on the main. the Hi / low was on the aux stick. this was a over drive transmission. The later and more popular was the 2 stick 6 speed direct. it had 1-5 on the main and Low/direct/Reverse on the aux (compound)stick.   both of these boxes had a married aux box bolted to them. 

Thanks for that explanation. I didn't know there where two types of the twin stick 5 speeds. I guess my uncle's 74 DM with a 237 and twin stick had the later version because he could shift through the gears in reverse.

[other dog]

On 11/1/2017 at 9:53 AM, kscarbel2 said:

The early 300s, with the scoop in the R-model hood, were the most powerful ever built. They could pull a building off it's foundation and up a hill.

I don't know about all that, I never tried it. But the 77 F model I drove with a 300/5 speed would definitely pull 25 tons up Christiansburg Mountain in 4th. gear.  In a van trailer too.