REOGasMackDiesel

How is Macks toploads versus Rockwells toploads ? !

I was told the Mack's were about the same maybe slightly stronger mechanically (gear drive section) but a lot stronger structurally (axle housing higher GVW) ? !

Though I also got told for 50s-70s Mack axles were top notch, than by the 80s and 90s they were about the same as everyone else's axles all the way through, and by the early/mid 2000s they were just Merit/Rockwell brand axles with a Mack brand tag installed on them ? !

Mike

The 1940s ? ! Is it that good ? ! Or just cheap to build ? ! I figured they'd of updated them at some piont, Maybe still offering optional toploader's with some sort of modernized suspension ? !

Mike

Wow they been offering them for a long time.

Mike

How long did Mack use top load axles ? !

I got passed by what looked like a fairly modern Mack truck tractor and it had top load rear ends in it.

Maybe they are still offered today yet ? !

Mike

Help out here E7 and E9 are a bit ahead of my abilities. The E7 is the Mack I6 ? ! The E9 is the Mack V8 ? !

I need to start learning them as soon they might old enough for me afford them one day. I think the MP7/8/10 series will always be beyond my means, I may just never own one.

Mike

Beautiful GMC truck, I'd pull that V8 Detroit out and replace it with a Mack I6/V8 diesel or Cummins I6 diesel ;o)

I guess the Detroit is ok, They just seemed to leak large amounts of oil.

Mike

I don't think those get cut up, Its the delivery vans that get cut up. They also run the delivery vans for 25 years than they cut them up.

I some how don't see that as being a 1988, Looks more like a 90s rig ? ! Auctioned off maybe ? !

Or

Do these also get cut up too ? ! Must replace them sooner too ? !

Mike

Well there are 2 different Macks one is Mack powered ENDT-673, with Spicer trans and rockwell's. The other unit is a Mack built unit which has all Mack running gear and a ENDT-673C.

A1's were the Mack powered/Mack built trucks. The A2s were Multifuels, and stand M50s were gasser's. Of course the reman's could have been any of them swapped to or rebuilt at a2 spec's.

The old timer, reconfigured his trucks as they were altered. So he built what he calls the "a3 series" ups them to a 355hp Maxidyne, replaces the 5spd's with a 7spd, and swap's out the 11.00-20s with 12R24.5s. Now he has all the pulling power he'll ever need and some good road speed too.

I asked him to join up a few times.

Mike

My great uncle has 2 1975 Mack's an M52a1 tractor and an M54a1 cargo. 355hp Mack diesels, 7spd Mack transmission's, with 6.38 gear ratios, and 12R24.5 tires. They run 70mph@2,000rpm in OD according to GPS ;o)

Two very strong pulling trucks, They sure guzzle fuel though !

Mike

Get some single Amber LED's from radio shack or some fact simily and drill out the dogs eye's, than install the LED's and make the bulldog signal. Heated mirror brackets are pre-drilled for wire routing ;o)

It looked awesome on the truck at the "auto-motion" show !

Mike

Must be nice, I'm poor so I drive antiques. I ran a V300 or P1525 Cummins 785 V8 they are a screaming machine. I actually rebuilt one and got to see it run on the dyno 317hp@3,300rpm and 595tq@2,600rpm !

Yep it was a wonderful boat anchor, up shift at 3100-3300rpm and down shift at 2000-2200rpm or other wise you'd come down the hills in reverse ;o)

When I rode with the guys running the Mack's they spun them out to 2100-2300rpm all the time, idle out the drive way to the paved road. Once on the asphalt they slam them to the floor pound through all 5 or 7spd's.

Mike

Thanks go to electronics and variable geometry turbos.

So nothing built today plays by the rules learned on 1950s-1980s trucks than ? !

The never below 1500rpm and never over 2150rpm rule is out the window ? !

No more ring glazing ? ! No more blown head gaskets ? ! All brands can now be driven as if they were Maxidyne's, Ran at 1250rpm-2250rpm, and maxed out at 2375rpm ? !

Mike

So the lower the rpm and the higher the mph = better MPGs ? !

Well than why run 1400-1600rpm, When 700-900rpm would be better ? !

If 1400rpm = 7.5mpg, and 2000rpm = 4.5mpgs. Than 800rpm should get about 9mpg's ? !

Technology has certainly advanced beyond my comprehension. If I ran any of the trucks I drove at 1400rpm I'd get kicked off the highway. Most wouldn't last very long operating below 1500rpm either. 2.xx gears ? ! Ha ! They barely did the job with 4.33 and 4.88 gear ratios !

Mike

I'm impressed they didn't switch to CAT's sooner with all of the MTVR's being CAT powered. Maybe even Cummins to match in with all the AM Generals still in operation.

I wonder why the Detroit's are getting rebuilt ? ! Normally a reman'd unit is updated to modern specs.

Like the 1950s M35's got the 331 gasser's replaced by turbo charged multifuels and later on the baby CAT diesel for the a3 series . . . Must be cheaper ? ! Or won't the CAT's fit the old rigs ? !

Well either way 500hp Detroit or 750hp CAT its a 45mph beast of a truck ;o)

Mike

They are built and rebuilt here in Wisconsin with pride ;o)

Mike

Beautiful truck ! Very nice looking ! Welcome aboard sir.

Mike

I only seen the truck in passing after that maybe 5 or 6 times.

So I can't really say as what it all was for sure. Tombstone radiator not the big wide job.

My guess was about a 1950s model anyway, Without finding the truck again its not likely we will ever find out just what it was.

Mike

Well .85:1 is a 15% OD so dual OD's would of gave him 30% or .70:1 in 15th gear. The fact he said it ran 65mph at 2000rpm and the large tires looked to be about 12.00-24 so he'd of had to be running a 6.3 to 6.4 axle ratio to net 65mph@2000rpm with .70 OD.

But I'm just guessing, Also claimed it was 711 diesel but I heard a turbo when he headed on down the road.

Mike

Beautiful truck ! Very nice looking rig !

Mike

There was a guy in madison, He claimed to have a Mack 15spd double Over Drive. Said 5th in his main was over drive and 3rd in his auxy was over drive. He drove B61 tandem, It had SWB, huge axles and tires !

Claimed his main box had .85:1 5th gear and a .85:1 3rd gear in his spliter.

Is that even a possible combo ? ! Than if so wouldn't you need a Maxidyne to make it work out right ? ! Or would a Thermodyne handle the twin Over Drives ? !

Mike

Wow first time I can remember Cummins having issues, Though its also the first time I have heard anything positive in relation to Detroit diesels ? !

Than again the newest Cummins diesels I drove were a 2008 Sterling bullet 5500 4 wheel drive with a 375hp 6.7L-CTD, and 1997 Frieghtliner FL70 with a 250hp 8.3L-CTD. From there I jump back to the 855ci I6 Cummins 240hp non-turbo to a turbo charged 400hp unit. Never had any issues so didn't learn to repair them ;o)

Grew up around lots of Mack's just never got to drive any of them, I was always running the other trucks that they claimed were "easier to drive" arg !

The only CAT I got to drive was a GMC brig with a 210hp 3208 that was on it last leg's been rebuilt several times and was well passed needing another one. Hard to start and no power under a load. I don't really blame the engine I am sure if it weren't all worn out it'd pull good.

My experiences with Detroit is they leaked massive amounts of oil and semi doggy but not to bad just a bit sluggish some day's. I was always pouring oil into them ! Dump oil in it in the morning run it at lunch time stop and pour in some more oil ! Left an oil slick any place it was parked or sat still at.

The IH's were like the Cummins and Macks add a little oil here and there other wised they to fired right up and ran great until they wore out. Some even still ran great when they were worn out. They got ran until they wouldn't start without ether and the oil pressure went to crap. Idling at 10-25psi running down the road only holding 38-45psi once wore to that piont they finished out the season and were rebuilt.

4.33's and 4.44's were highway gears to us, 4.56, 4.88, 5.29, 5.43, 6.17, 6.38, 6.44, 6.72, 9.02, 10.11, and 12.55s if memory serves me right. I may have missed some there ;o)

Sorry unlike most my coworker's I didn't just do the job and go home, I liked to learn all the details of the rigs and equipment I was using. Truck, trailer, loader ect right on down the wheel barrow and rack and shovel.

I guess I'm bit crazy . . .

Mike

Rev's to high ? ! I drove an older version freightliner a '97 FL70 it ran 70mph@2500rpm's.

Cummins-8.3L, 5spd manual, 4.33s, and 11R22.5s ;o)

Mike

These are "neat" posts to read about a week or so later ;o)

All kinds of them going around, from Fiat to renaming Chrysler American Motors to Oshkosh buying Mack.

To

The USA being sold to Canada and few saying China to buy Japan.

Mike

So Volvo is kicking the Mack family out ? ! What's next they selling the company for scrap ? ! These jokes are always silly.

Mike

Thanks much

Mike