67RModel

No too many people know very much on the Midliners around here anymore. I would suggest picking up some service manuals on Ebay. They seem to be plentiful. Getting parts for them seems to be very problematic these days.

Here is a better video and explination:

Had to look it up myself....Apparently (from the comments and how Otherdog says) the second guy to use the saw in the video is using it properly. Digging the cleats into the ground between you and the log and rocking the saw forward allowing the saw "tip" to pull itself into the material.

Yes very sad to hear this. Was he elderly?

Yes very common in waste facilities and Landfills where they use tipper trailers. A friend of mine had a DMM 6x6 with one on it. It was an ex Waste Management rig from one of their fill sites. He ended up selling it to another trash company that had a transfer station. Also NVR homes prefabricates all walls for their homes in a facility and bundles them up. The entire house is framed in that facility. Then they lay all the walls, bundles of plywood, and the rest of the home's material to a flatbed trailer and haul it to the lot it is going to be built on. The trucks that pull them have these types of 5th wheels. The driver removes a bunch of straps and the the entire load gets raised and slid off the trailer onto the ground next to the completed foundation. Pretty wild to see......

That was 41Chevy. He has since disappeared. I read a while back some were speculating he had passed on.

Wow. Air over hydraulic brakes. I have never seen nor heard of that on a Mack. What would be the benefit of doing this? I mean you already have an air system and are using rotochambers to actuate. Why would one decide to actuate a hydraulic master cylinder rather than a slack adjuster? I'm curious.

I would repower/regear an original truck. My personal opinion is medium/heavy duty bodies swapped onto a pickup chassis look like clown cars to me. I have a friend who put a B model cab and front clip on an international S series chassis and it turned out very nice. I would look for an International/Navistar mechanical DT360 engine. They are the same size (360 cu in) and dimensions a 5.9 Cummins and just as bulletproof. Plus nobody has one. A 5.9 swap is so tiresome. I like the 2 speed rear end especially if you are going to be hauling weight. The one in that Diamond Reo is probably geared super deep though. I would look for an old International S series parts truck or 90s Ford F700 with 2 speed rear for the axle and transmission. Whether or not you decide to go air brake or hydraulic brake will dictate a lot about what axles/ratios are available to you. Either the DT360 or 5.9 Cummins can be outfitted with an air compressor so it would be possible to do either hydraulic or air brake. Good luck.

Ok WOW. WTF even is that thing? Are you able to trace the lines going into and out of it? Where does the cloth braided line feeding it come from and where does the plastic line coming out of the brass 90 elbow go to? It also looks like it has a grease fitting on the end of it???? Also its pretty strange it is a straight truck and has a red button only but that could just be the old yellow diamond got brittle and and broke. The the old red/yellow buttons were removable off the valve with a small roll pin. Maybe they just threw that red button on the valve that should be there. Does the truck have hookups for an air brake trailer? Notice it says "trailer air supply".

I personally think Mack should have poured their resources into developing the Mack "Big Six" prototype that is at the Mack Museum. It would have been directly competing with 855 Cummins and 1693/3406A Caterpillars at the time. Given Mack's engineering prowess at that time, they would have had an incredible big bore, inline, "highway engine". While cool, the E9 should have never been. Mack should have let the V8 die after the 855/856 V8s. Its easy to say this in hindsight but I think the E9 ultimately handicapped Mack...

Now that I look at the first picture of the chamber more closely I see it is just behind the cab on the passenger side next to the exhaust. With the amount of wheelbase the truck has its hard to believe it is part of the braking system. What is it doing? what does the end opposite of where the airline is going in look like? Does it have a long threaded rod coming out of it and if so what is it connected to?

https://www.ebay.com/itm/305293929948?epid=6020591473&hash=item4714efaddc:g:XlsAAOSw07xlaIKz&amdata=enc%3AAQAIAAAA4FfL4slc%2FfeTIfN4OvvbVT%2F2%2FkdstS6lyDeiODSEWB%2BCRCpdK4uzo9seCgwqhDwdS5glAzMfVBlXnvI8UbyBaOfBIcr4F8Eo84qPsvIon5ReFzpMk%2Bb4IPYef1LRPzz5cT5QXx%2BRhoJONJYN62eX8Mgqb8eNEsg%2FgMkAoSVvjHD4mLaxfov2YlVDh9A3gZIEbRdilTXOi%2Fga1rZD2aeWY0%2BGZGQXQ5wz8X06NII0mnTB06OEZDUjiZ%2FU7EwQQfhL48NJJb8HOV4S7%2BpLuQZqP6M51f%2BqAm1Z7%2FcP2iq4qti0|tkp%3ABFBMwobWzo9j Try not to vomit when you see the price.....

That is an old Rotochamber......YUCKKKKK! Its hard to see from the pictures supplied, but is definitely a rotochamber of some sort. The ones I have seen are just single acting service brake chambers like a steer axle chamber. No spring brakes. My B81 had them and just had a brake drum on the driveline for parking. The other ones I have seen were on a DM800 but also had single acting, spring, pull type Maxibrake chambers opposite facing of the rotochamber connected to the slack adjuster with all thread or chains. if there was a loss of air the spring maxibrakes would pull on the slack adjuster.....Very queer setup but was a solution before 30/30s and similar were common or perfected. I don't know if the truck pictured has Maxibrake, pull type chambers on it but what I am seeing in the pictures is just a single acting rotochamber for service brakes. Very obsolete an insanely expensive to replace if you can find them. Like $600+ each. I think they are serviceable and there is just a regular rubber diaphragm in them if they are leaking internally. Very hard to believe these are on a 1979 but hey anything is possible. Does the truck have a yellow air valve on the dash for parking brakes? If not then I would guess the brake lining is stuck to the drums. Sledge hammer is in order.....

I cant capture the image of the MP8-505 hp and torque curves but here is the link to them: https://middleeast.macktrucks.com/powertrain-and-suspensions/engines/mp8/ E9-500 specs pictured below.....

The E9 was probably a big deal back in the day but honestly is not all that impressive by today's standards even when compared to a "puny", modern 12 liter engine. The E9-500 didn't even make 1700 ft*lb of torque. Torque is a very arched curve peaking at 1650 at 1400 rpm. An MP8 has constant 1860 ft*lb from 1100 - 1400 rpm. and The MP8's 505 hp is almost constant from 1400 to 1900 rpm. The E9-500 is only making 440 hp at 1400rpm and gradually climbs to a peak of 500 at 1900rpm. All else being equal an MP8 would easily out pull a stock E9-500. and a 605 X15 Cummins would blow the doors off the truck with the E9. My guess is keeping the MP8 running and out of the dealership service department would be problematic though.

Harbor freight makes one that works very well for like $35. It’s nice to have around. It comes with the reflective tape. https://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html

Please understand I'm not suggesting 300,000 illegals each year is an acceptable amount. I would say even 1/year is an unacceptable number while also understanding that would be impossible to achieve. All I'm saying is if this person truly did make the claim "the population of Pittsburgh/day" then he should not be taken as credible because the numbers don't lie. 300,000/per year is much more believable but grossly unacceptable.

Who is Dan Bongino? He sounds like a lunatic. The population of Pittsburgh is 300,431....Call it 300,000 for simplicity. 300,000 illegals crossing the border every day amounts to 109,500,000 people every year. The total population of this country is 332,000,000. Are we really to believe the population is growing by 32% year over year? It took since 1978 (45 years) for this country to gain 109,500,000 people. He had to have meant 300,000 total per year

I thought about this at one point too. These engines are governed at 1750 for fuel consumption / noise driver fatigue reasons. If you could wind them up to 2100 you could catch the next gear at a higher rpm....say like 1200 rpm. The difference in horsepower between 900 rpm and 1200 rpm is about 65hp, which is not an insignificant amount. Another option would be to install a Jake Brake and shift using the Jake. I think this a better option since a Jake Brake is a much more desirable thing to have than a 2100 rpm governor but obviously its much more costly. I guess you could have both as well. The attached picture is for a Maxidyne E7-275. I assume the numbers are similar for an E6....

I would say yes depending on the application. Its the Mack triple countershaft design so its tough as nails. Able to take a fair amount of abuse. Very simple design as it does not have any air actuated range selectors and valves to give you any grief. Just a lever and gears. If the truck has 11R24.5 drives it will do 70 at 1643 rpm and 77 at 1800 rpm. With only 6 gears the steps between gears are large so it wont maintain speed on large, long hills as good as a 13 or even a 10 speed would. That is just the nature of fewer gears....You need to let you road speed fall almost twice what you would in a 13 speed before downshifting to the next gear. I see your in Illinois so its probably a non issue.

https://www.ebay.com/itm/303437541988?hash=item46a6497264:g:jY8AAOSw-uheFgVS&amdata=enc%3AAQAIAAAA0D%2FwpcRCtlZSAi6k%2Fu%2Fxs0Iszv5wHurBV94JmZ7qEvgE%2BUZrOZ2dzbNdSgziLnNxwiXO3ofiPDOWK%2FHzDpYAZ04ZKHJIHLrkuYUZVMUfRhKnMyDrQUJgnRi4cFybsqGI78wmn8dFmB3xrR%2FRXC%2BJhtVdEL3wEUZVPSJNDVwWX%2BTCMFlkjwzTbesb6kQ%2FF0oH9ioQ7SHMX0gtSlfvEnwgW9bxCTpBB2cXORbRfKS2%2Bq8jOOKyrgFtjYMucT8TnP4X%2BNYPeLewQQPtLEPTzIhvM8Y%3D|tkp%3ABk9SR86frOyEYw Do yourself a favor and buy that service manual. Looks like the information you need is on page 4-37. Not too many people know anything about Midliners.....they are beyond obsolete. Hopefully you don't need parts for it. Good luck.

Looks like Houston, TX judging from the sign and phone number in the background of the last picture.

I can't say I know. I just know what a true 30-40% grade looks like and I would in no way whatsoever be wanting to be repeatedly starting and stopping on it loaded down with any amount of weight. I imagine you could get by with that setup for a while or a couple times but I don't think it will hold up long term. 30-40% grade is astronomically steep and I seriously doubt your setup was "designed" for that amount of driveline strain. Another thing to think about is what type of road surface will this be. There is a big difference if its soft soil versus an improved hard surface. And like I said earlier I would be concerned about starving the engine of oil depending on which way you are facing and how long you would be in that position. I'm sure its published somewhere the maximum recommended grade or angle its safe to operate one of these engines. Ideally I would think you would want some variety of Allison automatic and planetary reduction drive axles but that is beside the point. Only one way to find out....

Mack top loader axles are a double reduction design. Basically the torque multiplication is done in two steps rather than one. Much less strain on components and less of a chance to break things. Much more desirable for what you are attempting to do.

I foresee lots of driveline abuse and broken axle shafts or universal joints. Do you understand how steep a 30% grade is? A lot of people would struggle to walk up a 30% grade. Canton Avenue in Pittsburgh is often cited officially and unofficially as the steepest public street in North America at 37% grade. I have driven up and down it in a Honda car and it was scary quite frankly. Plus the top 2/3 are made of brick. Technically your not allowed to drive down it only up. I could not imagine driving up that hill in a truck loaded with 4000 gallons of water. Let alone stopping a 4000 gallon tanker on that hill and trying to get started again. If you did you would never shift out of Low gear until you reached the top. Forget 400hp. What you need is lots of gear reduction preferably planetary reductions at the wheel ends. Are the axles in the truck Mack top loader double reduction or conventional Meritor axles? I honestly would be worried about starving the engine for oil at such an extreme angle. I'm not familiar with where the oil pickup(s) are on these trucks but depending on where it is you might be sucking wind either going up or down. https://en.wikipedia.org/wiki/Canton_Avenue#:~:text=Canton Avenue is a street,street in the United States.&text=Canton Avenue is 630 ft,feet (6.4 m) long.