mumblymack76

I hope I am in the right section. Up to what year DM cab will fit a 1974 DM 600 dump which currently has a the round back style, 237 engine with twin stick? Any tips, advise or price range ideas will be appreciated.

My uncle has a 1974 DM 600 dump truck that needs a new cab. Does any one know up to what year DM model will fit this truck? I don't know if it matters but it currently has curved back cab style, fiber glass hood, with a 237hp engine and twin stick 6sp. It is still a working truck. What is the price range of one in good condition? Any good ideas where to find one in the Miami area for export? Any tips ideas on this will be greatly appreciated. Thanks.

This Mack DM 800 tractor is listed as the #2 off the line and the first of its type sold to the public. Could this be true? It seems to need quite a bit of work. I searched under Mack DM on ebay search but here is the link.

http://cgi.ebay.com/ebaymotors/1967-Mack-D...ercialQ5fTrucks

Is it me or is true that the MH was not as popular as the other cab overs in it's time? I noticed alot more cab over Internationals, KW/Pete, Freightliners etc than the better looking Mack MH when they were being built. They also seem to be quite a bit cheaper than a comparable conventional Mack and were alot less popular than over the road R models. I know that when the restrictions on the length of the tractor trailer's were lifted the production of over the road cab overs pretty much ended. However I would like to have seen more MH cab overs compared to the competition on the road. Any thoughts from drivers of the MH?

Did all the U- models keep the flat back cab after the DM/R models went to the curved back in 74? I notice some U-models of 80s build with the flat back.

Are the Macks made for export available with non-electronic engines, and do they still make the older Mack types or engines in other countries? I know that some car companies when they discontinue production of a certain model, still make it in other markets to keep costs down or because they do not have to meet stringent regulations in the foreign market eg. the original Beetle. It would be good to know that the R, DM or the older Mack engines etc are still made in other countries for their market. Some Eureopean Truck companies still made older model trucks for markets in South America, Africa , Asia years after they were discontinued in Europe. I think Britsh Leyland still made older Leylands and engines for markets in India and Mercedes still built older trucks for the Indian markets. I am almost sure that early Tata trucks were rebadged older Mercedes.

I visited the Haul Of Fame Museum in Canterbury C.T in 2001. It was great, not only was there very nice trucks inside but there were some interesting unrestored ones outside. Is it still there and is it still opened to the public? Some of the trucks were very rare or one of the kind. I remember seeing Mr Yaworski's End of the Line Superliner at shows but I have not been to many shows lately so I do not know if the collection is still around.

http://s8.photobucket.com/albums/a12/bigma...nt=100_3129.jpg

This is Roger Gerhart's U700.

Thanks, do you know why the U700 had a taller hood? Could be engines, different frame etc?

I wish Volvo had treated Mack the way Ford treated Volvo cars when it bought Volvo. Ford did borrow and share some some chassis/platforms and technology from Volvo but it not change its identity . Volvo cars still make great reliable cars and it is difficult or impossible to see a Ford connection from a customer's point of view. I am in the auto business that is why I have observed this. It would be great if the Volvos were just borrowing Mack technology and not taking the Mackness out of Mack. I think a Mack/Scania merger would have been a better fit and Scanias seem like tough trucks too. In todays market it is hard for auto compaines to survive without some type of alliance because research and development of technology is so expensive especially when they have to meet regulations such as emissions.

The frame can be whatever length was spec'd by the original purchaser, or it may have been shortened or lengthened afterwards to the length required.

A U model tractor is a lighter duty tractor meant for general on highway type hauling, usually with a 12,000 lb. front axle and a 23,000 lb single axle or 34,000 lb. tandem drive axles, usually on 20 inch rubber.

If I remember correctly the U models used a single 1/4 inch frame rail, whereas the DM in single frame configuration had a 3/8 frame rail, and the DM in double frame configuration had a 3/8 outer frame rail and a 1/4 inch inner rail. The DM frame is also a much higher section from top to bottom and tapers between the cab and drive axle(s).

Most DM's had an 18,000 lb. or 20,000 lb. front axle and 38,000, 44,000, 55,000 or 65,000 lb. tandems or the 38,000 lb single drive axle, usually on 22 inch or 24 inch rubber.

I'm generalizing here based on what I've observed over the years, I'm sure there are exceptions on trucks that were custom spec'ed for special applications.

I also notice that on the U-model the hood is extended longer downwards between the lights and the bumper compared to the DM or the R. I just noticed it today after going through the many wonderfull pictures on this site. I always knew there was something different in the looks on the hood between the DM and the U but could never quite figure out what it was.

Ben,

Scania and Mack go as far back as the 40's or 50's. Mack acquired the rights to use the open combustion chamber design from Scania for use in the 673 verses the Lanova pre-combustion chamber design of the 672. Now as for the V8 Scania might have influenced Mack or vice versa, not sure. But the two engines have always been very different in the fact that Scania uses eight individual cylinder heads versus Mack's four. The 865/866 evolved from the 864 just like the 676 Maxidyne evolved from the 673. They are very similar in design. Scania kept the 14 liter until about 1990 or so until they switched to the 16 liter with the new Streamliner cab and bumped the power beyond the 14's 500HP. Mack switch to 16 liters at the end of the 70s with the 400HP ENDT1000 later renamed to the E9.

Its a shame Mack did not push the V8 more and they should have bumped the power like they did in Europe (565 HP) and Australia (610 HP. They could have then gave CAT and Cummins a run for their money but emissions were their downfall. I guess the engineering team wasnt up to snuff. Sad really when you think of how powerful the 237 was for its time (and in a way still is). Mack was really a leader in engine technology at one point.

Did the 237 or maxidyne design have and influence from Scania or was it 100% designed by Mack?

A DM tractor would be the same heavy spec chassis used for a dump or mixer application, it's just that it has been set up with a 5th wheel and all the air and electric hookups to pull a semi trailer, instead of having a dump body or mixer mounted on it.

Thanks, was the frame usually shorter if it is a tractor and were there any mechanical difference to a U- tractor?

I know that Mack is now owned by Volvo and before that by Renault. I was sad to find out that the current Mack engines are really Volvos. Which engine was the last truely designed Mack engine? Could it have been the the E6 or E7?. Were the current Mack engines designed excusively by Volvo or were they co-developed with traditional Mack engineers here in the U.S. ? I hope that the current Mack transmissions and rears ( with driveshaft on top) are still 100% Mack designed. I appreciate your feedback. Thanks

When the dm production ended a few years ago , does anyone know who bought the last DMs. I was hoping to visit the factory and see the last Dm roll of the line but I lost track and when I found out the production had already ended it was too late. I have seen the last Superliner built because I saw it a Macungie and the owner had end of the line on the back. I believe he also has the 2nd to last.

I have always liked the off set Dm cabs and the U- cabs. From what I know the DM were for Dumper/mixer but I have seen literature with DM600 tractors but never one in real life, only the DM800 . I have also seen U600 tractors and was wondering what is the difference between the DM600 tractor and the U600 tractor? Is the DM heavier ? , because the few U600 I have seen seems to have smaller wheels compared to the DM.

Hi, am a new membwer of BMT. I grew up in Jamaica and In 1980 when I was 4 yrs old my Uncle bought a 1974 DM 600 2 stick tandem dump. I was extremely facinated by this truck, and from there on I was a MACK man. It was the first large tandem dump American truck around as most trucks at the time were mostly cab over British Leyland , Atkinson,Bedford and a few Volvos etc. Other people were also facinated and people would stop when the big Mack came by. Jamaica is very mountainous and the Mack was unbeatable for many years. It could climb hills and go places where other trucks could not go. Even when other American trucks such as Internationals, Fords, KW, etc started to get popular in the eighties and ninties , my Uncle's Mack was still the only Mack around and the newer American trucks could still not match it even though they had more powerfull engines. It still works everyday but the cab is needs replacing .The amazing thing is that it still has the original engine,transmision and rears. It has been overhauled but it still keeps going. It is probably the oldest working truck around . Other makes of trucks that are in the area have been through more than one drivetrain components if they last 10 or more years but not this Mack. Mechanics who work on all types of trucks there have told me that there is no truck built like a Mack. They are more Macks running around Jamaica now but since they seem to be more expensive , they are not as popular as the other American makes. The DM600 is my favorite Mack, and I hope to have one one day to go to shows. I build and collect model Macks. My bigest concern for Mack is that it does not lose it's identity and reputation for quality under Volvo. I know the Macks are not the same under Volvo but hope they will not lose too much Mackness.