One of the saddest aspects of our hobby is that limited production vehicles, sports cars, and other such vehicles are vastly overrepresented, while the pedestrian vehicles that keep us going as a society often get used up and discarded like trash. Perhaps the most underrepresented segment is that of commercial trucks. If you are looking for a unique old warhorse from this segment, this 1978 Mack MB 611 for sale on Facebook Marketplace in Woodstock, Illinois, may be the ride for you. Solid, with surface rust only, this rough but ready Mack can be yours for a very reasonable $4,000. What do you think its original role was? Thanks to Hans H. for the tip!
So, what do we know about this flat-faced Mack? According to the ad, this is a 1978 Mack MB 611. It has a 260-horsepower diesel engine and is backed by a 13-speed manual transmission. The seller also tells us that it has Mack rears with a camelback suspension. What this actually means to most of us is a mystery. If any of our readers, many of whom are repositories of heavy-duty truck knowledge, can elaborate, please do so in the comments.
We are further told that this truck is in nice shape with no rust. The pictures above and below bear witness to this, except for some surface rust. It is stated that the truck will run. However, the injection pump will need to be repaired because the fuel supply fitting has broken off. The odometer is said to read 92,000 miles, and the truck is equipped with a “wet kit.” One interesting feature in the pictures is the installation of what appears to be an RV-type air conditioner on the roof of the very Spartan cab.
The biggest question concerns the original use of this Mack. There is a thread on BigMackTrucks.com featuring what looks to be the very truck we see here. Some speculate that it was a U.S. Mail truck, while others think that it was used by the United States military in some capacity.
A look inside reveals a cab that would be completely foreign to someone used to more modern heavy-duty trucks. The dash and center console appear to be made completely out of steel, and the seat probably wasn’t very comfortable for a long haul. Slapping a rooftop air conditioner may have made driving this truck a bit more bearable. The question remains as to how it was powered, as these air conditioning units are almost always alternating current.
The seller’s statement that this truck has 92,000 miles on the odometer is factually correct. It is also somewhat ludicrous to assume that this is the original mileage. Trucks like this often saw hundreds of thousands of miles from the factory to the junkyard. If it were a military truck, then this might be the case. Government auctions occasionally feature vehicles with ridiculously low mileage accrued during their time with our armed forces. Those are usually hard miles, though.
Hopefully, some of our regulars will chime in on this find. There is a lot to learn from vehicles like this. While seldom seen anymore, they are important to our history. It would be great if this one was preserved.
Do you know anything about this type of Mack? If so, please share your thoughts and memories in the comments.
I’m sure a Cabover like this will make Howards eye twitch like Inspector Dryfus in the old Pink Panther Movies. ( Hope you know I’m joking Howard) Jeff when you said, “while the pedestrian vehicles that keep us going as a society often get used up and discarded like trash.” I couldn’t agree more with you, sadly might I add. This one has a Fifth Wheel on it, so it was absolutely used to haul trailers around. I’m not 100 percent certain, but, I don’t think thats an air ride seat, I think its solid mounted, so, you’ll feel EVERYTHING for sure. This is indeed a work truck, probably for local runs. We have way better experts on Barnfinds than me, and can’t wait for them to chime in. This is another great write up Jeff!! Thank you for puting these old workhorses on here. I always enjoy them!!!
In the ad photos is that a switch between the taillamps?
Have1949 Mack Eht.
En 354
10 speed moonshine
Hydraulic brakes
Gear driven compressor on engine fir trailer brakes and air horn
1st Mack sold by karstedts garage to local owner. He got it back and put a collector plate on it.
Then I got it with copy of original purchase order, nos parts , parts manuals and more.
Not moonshine!
Moonshift.
Argg!
Mono
Shift
Auto incorrect
Yes, they were work horses used by shuttle companys in the inner city delivery business. Very reli able and the camel back rear rode as well as most single axle air ride.Ford had a similar cab style. they were referred to as two story Edsels. most had 260 and 300 cummins. amazing stamina for a little truck.
Trucks like this are likely responsible for more bad backs and kidney damage than any other cause. I drove an old cab over F model day cab as a spare whenever my assigned truck was in for service. Those things were hateful and they had an air seat. If I had to drive this thing any distance I’d take a sick day! Still a good example of how trucking used to be when real drivers ( not steering wheel jockeys) ran the roads.
Wait, wait, you read it folks, even the author admits, and I quote, “the most underrepresented segment is that of commercial trucks”,,BINGO! Why is that so prevalent here? Unless the staff is in the Cayman Islands, how can they ignore the fact these posts regularly get a slew of comments? Ha,,,told them,,,what?
Okay then, 1st, someone ripped off the bulldog, how can one —hole look at another? Every Mack had a bulldog, even these. I’m not sure where or how the “wet-line”( hydraulic pump) came from, but I’d bet this was an old mail truck or some sort of military, because this would make a dangerous dump tractor. The hydraulic tank isn’t big enough for a dump trailer, maybe turned a belt? USPS still uses these Mack cabovers today. The a/c, actually just the condenser on the roof, was a popular add-on for trucks, but I doubt offered by Mack. All I can say, if you have any teeth left, this should rattle the remaining ones loose. The ride sitting over the steer could be described as atrocious, but all in a days work. For backing in, you couldn’t beat it. Almost like a road yard spotter. It is crude by todays standards, show a new grad this truck, they’d go screaming into the night, but very typical and this truck didn’t go very far anyways, strictly a city rig.
Not going to go into my usual rant about the sad shape our trucking is in, but rather, with the weather we are having in the east( nice here) a huge tip of the hat to the men AND women that run our rigs so we can enjoy strawberries at our kitchen tables in winter,,I still think about that with every truck I see,,amen!
Since my Peterbilt 359 fell into the BFs abyss, again, I’m done with tips of any kind, but if you value your viewers, give ’em what they want, more trucks. Thanks, Jeff.
The BFabyss is very frustrating…. Especially on a longer well thought out post.
When I see a photo of a semi truck, I always know there will be a note from Howard! Always enjoy your comments.
Yes, those roof top a/c condensers were usually plumbed to lines from an engine powered compressor that was driven by a belt.
I remember driving by the Mack Truck Headquarters back in
1979.Too me,it’s sad that so many American truck companies have
been taken over by foreign companies.
that was due to our own folk (young MBA hotshots) selling them out for good 1/4ly stock reports – not long term durability income and products so the ol greyhairs could congratulate them.
And they claim this is patriotic?
Why can’t I edit after I post? I forgot to add that we have a fairly
new Mack truck plant South of Salem,VA,& a newer Volvo truck plant
in Pulaski,VA,both not too far from here.
You must be around Roanoke?
MB Macks (replaced by the MR) were as common as the trash they hauled. Overnight had them for tractors, cities across the country ran them as trash trucks, many freight companies used them for intercity delivery. Don’t think I ever heard of a 260hp unless it’s a Scania, and most any Mack engine would twist that RT613 in two. Kinda long for the average tractor. Camel Back suspension? Come on guys! Doesn’t that spring stack look like a hump on a camel’s back?
260 hp does seem a bit odd. Could easily be a Scania. I used to see a lot of Scania engines in COE especially. For 260 hp I sort of doubt it would be a DS8 but rather a DS11. Worked on both, mostly in trash collecting trucks.
It could also be an RVI which was supplied by Renault. I have my doubts that it’s a genuine MACK E-6.
Mack was somewhat of a mixed bag in the late 70s/early 80s. The trend eventually swung back to the E-6/E-7/E-9 and stuck with it for a long time although the lighter versions were pretty much switched to the RVI.
We put lots of all of them through our shop. I might add that a real popular engine for this vintage was the 3-PLUS. It seemed that if it was a single unit conventional it was a 3-PLUS. Actually liked working on them…
Hey Geo, the whole thing is a bit of a mystery. I’ve worked on the Renault engines, but only in Mid-Liners. The choice for transmission is what gets me, usually the Scania and Renault engines were backed by a Spicer or EatonFuller 5sp. Maxidynes were mostly backed by 5 or 6sp Maxitorque, although I have seen 13sp RRs in long haul tractors. The 610 and 613 RRs were just a up-grade over a 5×2 setup in harsh service and depending on the driver couldn’t hold up behind an 1100/3208 Cat, and would in no way last behind a Maxidyne!
Hey Jim, I read, because I’m not that smart, and upstaging Geo is always risky, but in ’78 Mack did make a “ET673-260hp”, the smallest “Maxidyne”, and catered mostly to garbage trucks. I agree, too long for a USPS truck, and could very well have been a garbage truck someone slapped a 5th wheel on, although, the controls inside say it always was a tractor. Camelback was durable, but a rough riding son of a gun.
Hey Howard, I wonder if someone set this up to pull a “Landoll” or similar trailer, low weight but hard to load stuff. The RR RT613 gives you 3 gears under 1st (deep reduction) for job-site duty. The small tank for a wet line would work with a double acting cylinder, but not for a single acting cylinder like a dump trailer.
Mack’s seem to have the garbage truck market up here for sure Jim. 🗑 makes sense w their infamous low roofline 😒😃
Lots of farms in that part of WI. Could have been a farm truck, which don’t see much time on the winter roads
Hi Hans, no need for an A/C in Wisconsin and fuel tanks too big for a farmer, but I agree, as “remastered” as it is, no doubt farmer owned! :)
This has to be among the homeliest of these types of trucks listed on BF.
Although there were far more homelier trucks out there…..
may not needa driver?
Given the drivetrain, low miles, wet-line, and an RV sized A/C unit, AND the proximity to quarries in the area, I’d estimate it was a pit truck pulling dump trailers out of the pits. Said because this would be one scary handling road unit. Bear in mind, at, around the 1978 time period, two-sticks were dwindling, except for some conventional units. Just my $.02
The Beer Companies in New York used to use those Mack’s as delivery trucks, such as Reingold, Schaefer, Ballantine and KnickerBocker. Also wholesale groceries delivery such as Otto Bermann had a fleet of those trucks
Oh boy Ballantine beer,my pop use to drink that back in the 60’s ,they were a sponsor of the Phila.Phillies at Conney Mack stadium.
Howard, Jim, and GEO have covered most of the answers. An unusual truck, especially the way it is spec’ed. The majority of the Post Office MB’s were single axle.. I sorta think this may have belonged to a LTL freight hauler as a city tractor for delivering heavy loads?? The 13 speed is a puzzler, especially the light duty 600 series, although with only 260 HP a driver would need all those gears if he had a heavy load. The wet kit is probably for a Landoll type roll back trailer. The roof mount A/C was a common add on in this era. This is a very refrubrushable unit for picking up new toys or hauling toys to shows.
Having never been a trucker for a living. I have driven an 18 wheeler once. An emergency situation taking over for a heart attack driver. I only drove it about 275 miles on mostly level highways. So I always appreciate the truck drivers. And like our service men and women, THANK YOU FOR YOUR SERVICE TO OUR COUNTRY! And not to forget the people that kept the fleet rolling. (Like geomechs and Jim Randall, thanks again Jim fir the huge favor) many thanks to you guys also! That being said, I was a certified master technician for medium and HD trucks. But I never turned wrenches for a living. I was always the boss in charge. (THMFWIC) And in my second profession, I sold and spec’ed trucks. So I enjoy the discussions about the specs and use of the rigs discussed here.
Barn Finds writers keep up the good work!
Hey Wayne, parts should be there tomorrow unless they came early or are snowed in somewhere. Good luck!
Thanks a ton Jim!!!
Not really a Mack man, but it would seem that it probably was in the refuse industry, possibly hauling push out compactor trailers somewhat locally which were used extensively before the modern “live floor” design.
Also, I doubt that transmission is a 6-13. The model for the time would be a 95-13 which would be more than adequate for 260 horses. The “6” and the “95” denote torque ratings multiplied by 100 and of course the “13” was the speeds.
The hydraulic tank seems to be about 30 gallons which I believe would be enough to do that job.
I have seen a couple of these turned into rat rods and they looked pretty sharp.
Hey Steve, you can tell a 613 and a 915 from the taper of the back box, the countershafts taper from front to back and so does the case. They are deep reduction units. 9513s and 12513s were OD units with a hump in the case at the left top and right bottom to handle the large countershaft gear for OD. The seller says 613 and going by the shape of the case I’m good with that.
I guess I missed the part where he said it was a 613. Doing a little research, that engine, an ET-673-260 was normally mated to a Mack T2130 13 speed tranny in 1978.
As I recall, those Mack transmission looked somewhat similar to the Road rangers.
That engine in that configuration produced 930 ft lbs @1300 RPMs so, a 613 would be sorely underated for that motor.
T2130/T2180 were all triple countershaft transmissions.
Ken Smith, me too !
We got some guys here who know trucks!
Thanks-
These were quite popular as garbage trucks. Predecessor to the ubiquitous MR, that first came out later in ’78. They used a whole gamut of engines, from mid range Caterpillars to the ENDT series Mack six cylinders. Nice rig.