Uncommon heavy truck shifting pattern

[ebinmaine 67,311]

A lot of you are well aware that I have a great liking for heavy trucks and especially the older ones.

Favorites of mine would be the old style Pete conventional like a 359 or better yet an older one like a 60s vintage needle nose.

And then of course there's the good old Mack truck.

Square cab R or construction DM series from 1964 or 5 all the way up into the 90s.

 

I like those older Macks enough that I have a tattoo on my right forearm that is the original patent copy from the drawn design of one of the Mack Brothers for the three-dimensional hood ornament that came out in 1931... Fully accurate including the radiator cap with fastening ring that the bulldog stood on back then.

 

 

 

Well I pulled into the diesel fueling station today with my crane truck from work and a fella pulls into the next bay with an old Mack dump truck.

 

We got to shooting the breeze for a minute and he was telling me that the truck was built from some sort of a glider kit in 1988 and that's how it's registered but it's only the cab that is that age.

Engine is a 1968 and as for the rest of it he doesn't even know...

He tells me it's a twin stick shifter.

The primary shifter is five forward gears and no reverse. The secondary shifter is what he refers to as the power divider. It had direct drive of course and also low range. And that's where his reverse was. So he had five full usable shiftable reverse gears in that truck.

 

It has 10 literal forward speeds of course but you only use one or two in low range and then shift up to high range so it's actually marketed as a 6-speed.

 

I've been around trucks my entire life and I've had my CDL almost 20 years. My father has only been around them for about 50, 55 years maybe.

 

Neither one of us had ever heard of a primary transmission that had no reverse. 

 

How about you folks?

 

[stevasaurus 22,711]

Not me...I drove the (I want to say) 15 speed Road Rangers (Ford) when I was on the line gang at ma bell back in the 70's-80's.  They were not 5th wheel, but we pulled the long trailers with Ditch-Witch and Vermeer trenchers on those.  We were over 50' long and needed a "CDL".  The truck carried the cable on reels.  Lot's of weight.

[Maxwell-8 4,275]

Our fiat 850 dt has a similair gearbox set-up. 4 gears in reverse and 12? forward

[ClassicTractorProfessor 5,314]

@ebinmaine I actually learned how to drive a truck in an old Mack with the same setup you're referring to. I was probably 13 at the time. Dad was working for a company hauling produced saltwater from oil and gas wells to a disposal well. 90% of his miles were on dirt roads and private lease roads, I would go with him to work on Saturdays and drive the truck in the afternoon while he sat in the passenger seat and caught up on paperwork for the week. Few years later I went to work to a farmer the summer between my junior and senior year, and he had one as well, hauled many loads of wheat during harvest that summer with that old truck, as well as a few loads of hay and several loads of cattle. 

[rayshorses 102]

That was a very popular transmission used from mid 60s to mid 80s in the Mack dm and r model  600 and 800 trucks. It was called the six speed with lo hole. The main had five gears and the compound had lo lo ,lo and reverse , You could shift through the five gears in reverse . So . if you had a heavy load you would put the main in first and the compound in lo lo to start , then shift the compound into lo , then from there you shifted the main for the next five gears. Mack used the maxidyne series engines with these transmissions because you could lug them down to 600 rpms and they would perk right up to 2100 rpms . I had that transmission in my R 700 with the v8 maxidyne. The power was enough to lift the left front wheel off the ground.

The macks prior to these had the thermodyne engines with the infamous quad box transmission. It had five gears in the main and four gears plus reverse in the compound. You would start in first gear main and shift the compound four times without the clutch then go to second , compound back to first and go through four gears again , an so on. Shifting was mostly done with both hands , sometimes with one arm through the big steering wheel and you were shifting constantly because the thermodyne had 160 hp. My DM 600 had that setup and at the end of the day i would be drenched in sweat even in the winter , mostly due to remembering which gear i was in. If you messed up going up a hill , it was back to first gear and that is where you would stay until you reached the top. Those were the good old days.

[ebinmaine 67,311]

4 minutes ago, rayshorses said:

good old days

As much as I do love runnin up through the 10 speeds of a modern Eaton Fuller I have to admit the newest Allison Automatics are making me a little spoiled and a lot less sore...

 

[WHX?? 48,798]

All I can say EB is grind me a pound .... or ... if you can't find em .. grind em... there was another good one about a stripper pole but I CRS and a family site! 

Edited October 7, 2021 by WHX??

[rayshorses 102]

The new automatics sure are nice. My new hydroseeder truck has an 18 speed with a 600 cummins. We went with the 18 speed for the wide range of gearing, We need to go very slow at a constant speed when seeding roadsides . It's hard to maintain a constant low speed with an automatic when going up and down grades. My buddy just bought a kenworth tri axel dump with an automatic and a two speed gearbox . He says it will maintain low speed , but i think it's awfully hard to know the difference in a 1/4 mile per hour rate , and that speed makes a big difference when you are trying to spray seed at a constant rate. I will probably go with an automatic for my hay mulcher truck when the time comes because constant speed is not as important for that task.