B61TENDT711

I'll more then likely go with the Mack T2070 trans just to keep it Powered and driven Depending which engine they give me the best deal on when it come time to buy will be the one i use . a 237 is all i need a 350 is what i want so i may compromise and go for the 300 ! But the 237, 300 or 350 any one of them 3 should do the job perfectly well. . . Mike

I will be the only driver of this truck so i'll know the limitations of the components and i won't be "Ram rodding or hot rodding" it around i'll be nice and gentle with the high torque engine and low geared rear's Mike

T2070 Mack trans .60:1 OD = 58mph@1,900rpm with 6.44:1 gears and 11R24.5 Firestone T831 tires so max road speed would be about 60mph-62mph at 2000-2100rpm. So then can pretty much any of the above engines be mated to the 7spd-OD Mack trans ? Mike

the trouble is the only gearing option you have is 6.44's. i was going to simply swap the 11.00-20's for 11R24.5's which will give you about 5-7mph gain on the cruising speed more or less truck prolly won't run faster then 55-57mph maxed out in OD, it'll be toy just has to be tough enough to pull the slightly larger tires and push the empty tractor around... The Spicer 5spd-OD has to be good to at least the 800tq as it the same transmission used by the 855 Cummins which had 3 rating during the it's use in front of the 5spd-OD which was 240hp n 680tq / 250hp n 735tq / 260hp n 800tq. . . this same 5spd-OD came behind: 855 Cummins 673 Mack 465 Multifuel. I want add some power yes but i was hopping to keep as close to original "looking" as possible Mack engine, i am thinking the ENDT675 would be the ideal option for this as it can be simply swapped in place of the ENDT673 . I was simply trying to be greedy by trying to stuff the 350 mack into this low geared truck but i'm sure the 237 Mack will be more then enough Mike

I'm sure he was thinking the "deuce and a half" these are not a deuce i assure you. . . there is plenty of room for a 300 or 350 Mack, I wasn't sure as to how hard one could push the interchangeability of the 673 with 675 676 E6 aka 237-350 ? would the 350hp Mack handle the Spicer 5spd-OD trans ? or would the 7spd Mack trans have to be used ? is the 7spd-Mack an Overdrive trans ? Mike photo 5ton 6x6 tractor:

Now isn't the 300 n 350 horse power units also able to pull the spicer 5spd-OD ? If they can fit an 855 cummins wouldn't the ENDT676 350hp unit fit ? Edit: On second thought the 237 should be just fine on the spicer 5spd OD as I'm going from a 200hp n 600tq motor to a 237hp n 900tq motor the 250 cummins only had 800tq so I would be at about max power for the trans anyhow... Mike

Good stuff thanks for the info Tho i was also planning on swapping out the 11.00-20's for 11R24.5's which will bolt right up and clear perfectly, which would then get away from a split rim tube type tire no stock's but can special order to a tire that most truck shops have in stock plus it gains me 5-7mph in max road speed which helps on a 50mph. . . Now will the 237 be able to pull the 2.5 inch taller tires with 6.44;1 gears and 5 forward speeds ? Mike

Just remember Old trucks never die they just lose weight increasing your pay load Mike

I bet the 5spd works with the Mack as the Cummins is also a 1500-2100rpm ranged engine, and because of the lower revs the Mack n Cummins units got the OD 5spd manual trans. . . this dealer posted has the 673 available in 220hp,another dealer where i saw the mack engines was clark truck parts. I emailed them and asked about the 237hp Mack diesel and yup your right it was the ENDT675 they got a deal on a few dozen of them and where swapping out the 673 for the 675. . . If i was to get my hands on the Mack powered M52A1 tractor would i be better off swapping the Thermodyne 673 for the Maxidyne 675 as they did because the truck is only a 5spd ? would it then be more worth while to swap in the 350hp motor with the 7spd trans if i'm going threw a the trouble of transplanting ? Mike

So then if the 673 was designed for the multi speed trans then how come it help up to pulling 75-100K-Lb loads with just a 5spd trans mission ? wouldn't the truck have lugged = blown head gaskets ? I was always told NEVER lug a Thermodyne !?!?!? http://www.memphisequipment.com/Products/5ton.asp Engine #1 Cummins...Model NHC-250 Horsepower...250 @ 2100 RPM Displacement...855 cu. inches In-Line 6 Cyl. Non-Turbocharged Engine #2 Model...Mack ENDT-673 Type...In-Line 6 Cyl. Turbo Charged Horsepower...220@ 2100 RPM Displacement...672 cu. in. Engine #3 Hercules/Continental Model LDS-465-1A Horsepower...205@ 2600 RPM In-Line 6 Cyl. Turbo Charged Displacement...478 cu. in. Engine #4 Continental...Model R6602 Type...Valve in Head, 4 cyl, 6cyl Horsepower...196 @ 2800 RPM Displacement...602 cu. in. Bore...4 7/8 Stroke...5 3/8 Oil Capacity...22 qts Clutch Spicer...15" Single Disk Electrical System 24 Volt (optional 12 volt) Transmission Type...5- Speed, Manual Spicer...6353, 5th Gear overdrive Spicer...6352, 5th Gear Direct Transfer Case Rockwell...Model T-138 As you can see there is nothing but 5 speed manual transmission options !?!?!?!? Mike

ok so then the Military truck is really the ENDT675 as it has a 5spd manual transmission. . .that is how they got a 237hp Mack turbo diesel ? either way the transmission is a 5spd there was no other trans option 5 forward speeds 5th was OD in the multifuel n mack engine 5th DD was for the Gas engined truck. Mike

Now you call the 237hp an ENDT675 as where the 237hp Military truck had a ENDT673 Confusing . . . I want to try n Find a Mack powered M52A1 5ton 6x6 truck tractor 237hp Mack turbo diesel 5spd spicer 6453? i think anywho 6.44 gears 11.00-20 tires. I was hopping to find one these trucks some day swap on a set of 11R24.5's add some stack's and roll on. . . Mike

so it's still in the BUY ME stages. . . Mike

Are they still testing these unit's ? cause a friend of mind who is in the great sand box hasn't seen hide nor hair of this truck. . .But he says it sounds like a truck they could use desperately in a 6x6 version as well as the 6x4 version . . . Mike

Hmmm i was told the 237 300 n 350 would spin right out 2300-2400rpm's and started pulling around 1,100-1,300rpms. I also got the 237-350 Mack engines would withstand running 2200rpm down the road if loaded heavy on short trips then other say they'll hold 2250rpm all day long loaded or empty. . . Mike

Whoa 900TQ ! Now that thing is a beast i'm told these things can be rapt right out to 2,400rpm shifting threw the gears and it'll hold 2200rpm sustained. any truth to this ? Mike

wow trucks a beast ! I haven't seen any in person yet but they must be out there then. It would make a fine 6x6 shocked they didn't go with an all whee drive version. . . Mike

yea that i know there all Cummins powered unit's or they have the Multifuel unit. . .I don't want either of those 2 i want the mack powered unit. . . Mike

Factory power settings: Hp n TQ numbers ? Maximum Rpm ?( redline) Max sustained rpm ? ( highest rpm safely maintainable) Can the motor be turned up ? if so what kind of numbers can be turned from it ? year range ? cubic inches ? I want to some day own a military 5ton 6x6 truck tractor powered by the Mighty 237 Mack, so i am trying to learn any and everything i can about the motor if you have any info about the engine or even the Mil-spec 5ton truck it came in do tell i have open eye's n ears. . . Mike

I heard there was a granite Mack armored up as a military prototype any body if this truck made it to production ? Is there any Spec info on it ? Motor ? power ? gear ratio ? wheels n tires ? configurations? ect . . . Mike

Good to be here. . . thank you Mike

More then likely so. . . I have 2 Old Mack's and looking into owning 2 Military Mack trucks as well. . . The M123A1C is a Mack/Consolidated Basically its all Mack with a 785cid V-8 Cummins N/A diesel, turning 300hp n 900tq. The M52 is a 5 ton Mack 6x6 powered by the 237hp Mack turbo diesel engine. Maybe some day soon i'll get them trucks but for now i'm just a working man surviving. . . Mike

I too just registered on up, that fine B-model registry dose have my B61 on there some place i know i added it years ago. Mike

I just joined up seems to be a nice place here dedicated to Mack trucks. Mike