ThaddeusW

The biggest Mack truck produced was the M100, a 100 ton 6x4 off highway dump truck. It was powered by a 1000HP Detroit Diesel, believe its a 16v71. Only three were made and I believe all of them were used for heavy haul. One is very close by me hooked to a 600 ton trailer, owned by Pile Construction. It has two ladders up each side of the massive radiator. Here is a link to a members gallery with pictures of the M100 , I believe that is the truck and possibly trailer that is near me, John (aka, 45LMSWM) would know for sure. Other Dog posted a Picture of an M75SX, a 75 ton haul truck. I think they were powered by a Cummins VTA diesel or Detroit Diesel 16v71. An interesting fact is the M45 and smaller single axle M series all had two seat cabs. The Larger trucks like the M50, M60/65, M75 and M100 were single seaters. The M45 was the most popular off highway Mack truck and many were used as heavy haul tractors. You can easily find pictures of them. Go to this link for Bigge Heavy Lift & Transportation and check out the Prime mover gallery, lots of great pictures of their two M45's pulling Goldhoffer hydraulic trailers. Real awesome stuff.Plenty of M45's still working today.

Bad quick release valves. They are designed to allow air to pass through them in one direction under pressure and when the pressure drops they open venting the air. This allows the air to vent as close to the brake chambers as possible giving you a quick response. Your spring brake quick release valves are gummed up. I don't know if you can rebuild them but I would say replace them.

JAC is the company that produces Chinese Scania knockoffs. Curious to see how this works out.

Looks like they are getting a head start on Euro 6.

That is one pretty looking fleet.

No, the 711 is a diesel engine. The 707 is a spark ignited gasoline engine. None of the gassers were turbo.

Yes there were a few gasoline engines made by Mack. The biggest is the strait six EN707. I think the 707 block is very closely related to the 673/711 block. But insted of an injection pump you had two distributors and a carburetor on the intake. None of the gassers were turbo. There were smaller strait six and V8 flat head gassers. The EN404 is one. I am sure many others here can provide more info. Oh and Mack also used a Chrysler V8 big block in some of their trucks. Someone has an R400 powered by a ChryslerV8, all factory original.

Those images are tiny! But the one on the left looks to be normal height so I highly doubt it is a 6x6. The one on the right could be a 6x6 but Dayton wheels on the front driving axle is quite rare. It looks like it is most likely a heavy spec tractor and is higher because of the heavy suspension and larger tires. An RD in 6x6 is something I have not yet seen. But there are companies that exist who will convert just about any truck to 6x6 so its not impossible. RMM's and DMM's were available with 6x6 options.

This is probably the model you saw, a Mack RMM. The DMM was also available with a 6x6 or twin steer 8x6. Someone has to have the picture of the 6x6 granite from Macungie.

They sure as heck do! And I am sure you can have it spec'd for your task as you see fit. I sat in one this past Macungie at the Mack plant. Pretty darn high because of the front axle. Front axle was a Marmon Herrington planetary hub reduction which uses Euro mount wheels. Transfercare if most likely M.H. too.

My friend rented a room from a guy who was scammed that way. Too bad it was sent there. BUT I bet it will keep on working for a long time. When things are scarce the value of it goes up so those trucks over there are kept running and maintained as best as possible.

Hi there, The long hood R models were the R700 or RS700. Those models could have a Mack in line 6 cylinder, Mack V8, Cummins, CAT or Detroit Diesel. If it had a Mack V8 it would (should) have a V8 badge on the side. The V8 badge was only for the Mack V8 so a Detroit Diesel 8V71 or Cummins 903 V8 would not have a V8 badge. Other than that there isnt much else from the outside to tell what was under the hood. If you had the exact model number eg. RS797LST. Lets break down the Model number RS797LST: R - R model S - Steel frame (this is a "western" Mack model designation, for Mack's made in the Hayward, CA plant. L would denote an aluminum frame) 7 - Not 100% sure but pretty much means a longer hood 97 - Engine code, 97 is for a Mack ENDT866 (I think) L - Light weight components like Aluminum doors. S - Six wheel chassis T - Tractor

My guess is the very tall rear ends (tall meaning higher ratio number) makes up for the lack of gears. These trucks weren't speed demons but rather built for serious hauling over rough terrain. The ratio is given as 6.44:1 which is pretty darn tall. As for swapping motors, the transfer case might be a weak point if you put in a high torque motor. But I am sure swapping in a 237 Maxidyne would be fine as long as you don't abuse it. The only thing to worry about when doing engine swaps in those M39's is the amount of length you have before you cant properly couple the transmission to the transfer case. Meaning you cant have a transmission that's too long. I have seen CAT 3208 boat anchors put in them but not something as big as an E6-350. The 237 Maxidyne with a Mack 5 speed might be a great fit.

I read this last night, is it true? Nothing on the Mack news site nor on the Volvo global site. Interesting news to see, makes sense since they got rid of the Macungie Corporate offices. http://www.hankstruc...p?topic=37575.0

Thanks for the correction Herb. Somehow I confused the R model intro date with the Maxidyne intro date. Here is a question then, was the 711 indeed 711 cubic inches?

The 673 is short for the END673 or EDNT673 (T is for turbo model) model of engine which came out in the 50's and powered B, G, and L models as well as early R, F and DM models (I probably left out a few). It is also known as the Thermodyne Diesel engine. The number 673 stands for the displacement in cubic inches. Now the 237 was the successor to the 673 and looks very similar to the 673. The number 237 is not the displacement but rather the horse power output of the engine. Its model number is gives as ENDT675, just 3 more cubes then the previous 673. It was given the name Maxidyne. Maxi is short for maximum and dyne is a unit of force who's name is derived from the Greek word dynamis, which means power. So Maxidyne means Maximum power . It was a wide torque band engine so instead of needing 9/10/13/18 speed transmissions to keep the engine in its peak operating band you just needed 5 or 6 gears which greatly simplified shifting. It was introduced around 1963 1966/67 and quickly became popular for its grunt and pairing with simple 5/6 speed gear boxes. Now the M39's (The M52 is the tractor version of the M39) Were powered by the Mack ENDT673 Thermodyne, not the ENDT675 Maxidyne. The reason is Because the M39 was introduced around the early 50's, the same time the 673 Thermodyne came out. Here is a link to the Olive-Drab info page. As you can see the 673's were rated at 210HP @ 2100RPM and 610 ft-lbs. Your best resources for military vehicle Information is Olive-Drab or the Steel Solders forum.

Well first off reversing the wire to the starter will make it spin the engine backwards. So that needs to be replaced or rebuilt for negative ground. Alternator also needs to be rebuilt, rectifier swapped for negative ground or replaced with one that is negative ground. Any DC motor that is wired backwards will spin backwards. So any pump or wiper motors will also have to be reversed. If a motor is designed with a grounded case then you might have a problem mounting it and getting it to spin the other way. Feel free to keep asking questions.

Thats a heavy spec Actros, V8 engine and 70k planetary axles. Probably rated to pull over 200 tons, is a 2008 and most likely has very little miles. Go to kenworth and spec a C500 with SISU 70k axles, twin steer 20 axles and heavy double/triple frame and I bet your looking at over 500k. Just have a look at these late model used heavy spec kenworths and compare the prices. Hell a C500 with big planetary axles built for heavy hauling is close to a million. The transporter featured the Renault Magnum which is quite unique when compared to other European trucks. Most of the other makes have cab suspension options such as full 4 point air, half air and half spring or full spring and they don't wobble like the Magnum. Some makers feature a completely flat floor or have flat floor options (Renault Magnum, Mercedes Actros). Pretty much every maker features a super space cab that allows you to easily stand up and some you can stand on the engine tunnel and not bump your head. As for the ride, depending on the cab suspension I bet they ride better then a conventional truck. Those Europeans aren't slackers and their length laws are quite strict. They took every effort to make those cab overs ride as smooth as possible. They also have to pass strict safety standards so front end collisions aren't as dangerous as you might think. I have never rode in one but there are a few Europeans who have driven both and they mostly agree that a Euro cabover rides better than a long hood Pete. Some can be specked to the point where they can ride like a Cadillac. As for mileage the new DAF XF105 and Mercedes can claim mileage upward of 10MPG with their new engine technology.

Oh I know that the power draw will most likely be more due to losses from the hydraulic system. I just figured I would throw that bit of information in the mix.

I assume its a bare chassis? If it has a body please tell us what kind. My guess is around 16,000 pounds.

I know Kenworth has a hydraulic driven fan option for severe service trucks. I don't know any of the details though.

That is one awesome looking truck. I love the last page with the Bull dog painted in camo like the rest of the truck. That would be a great promo picture for Mack military vehicles or a calender or desktop wallpaper. As for the emissionless MP8, thats the great part about military vehicles, no emission crap that can strand a truck in a war zone. Also goes to show you how much juice they can safely get out of those engines without needeing to meet emissions. The MP10 should be able to hit 625-650 HP with 2250 ft/lbs like the old Volvo D16 rating before 2007. Oh and some food for thought: I have a diagram comparing Euro and EPA emissions. Euro 5 is equivalent to EPA 2007, in fact a bit more strict. But they have engines turned up to 700HP and 2323 ft/lbs of torque! And Australia has a 500HP option for the MP8, along with 1770 ft/lbs.Looks like we get the short ond of the stick, thanks EPA!

With a wood block between to prevent slipping! A jack stand would also be a bit of life insurance as well (for you and the truck!)