One thing about a truck with boxes......it was a great learning experience! If a new guy could get the knack and get the truck up to highway speed without having to stop and start over...you had accomplished something!!
Hay...beef on the hoof..logs....grain...that's what I hauled!

I learned to drive one in 73, in the mountains of SW Montana..off-road. Nothing tougher than rough roads, hilly terrain, and a loose steering system.


Man...those really were the days!!!

Oh yeah..Mac's weren't the only trucks with the twin sticks...AutoCar, Diamond Reo, Marmon, KW, Pete, International......they all had models with twins!!

Actually, you use 3 of the gears in the auxiliary (2 thru 4 on a brownie or lo split, direct & hi split on a Mack Quadruplex) to split each gear on the main (5 speed) stick. The 1st gear on the aux stick (also known as lo-lo on the Mack Quadruplex) is a deep reduction gear for off road use and is not part of the on road shifting sequence.

Unless your split shifting with 2 hands, you don't want the brownie (aux) in neutral when you're shifting the main stick, because then you have nothing to sychronize your engine RPM's to.

For the first 10 years or so of my career I ran Mack Dump trucks & tractor trailers with the Quadruplex 5X4 transmission in the hills of CT and NY state.

I've always thought that Mack should have designed a triple countershaft edition of the Quadruplex transmission which would stand up to the torque and HP of todays engines, then we would still be able to enjoy shifting with 2 hands.

Never a need to stop & start over.

As long as the driver selects the correct gear at the correct engine RPM's, it WILL go into gear.

Yer right Split ....but when yer 13 years old...and your teacher is 73 and yelling at you.....things can get exciting!!!

I did learn to get it right!!!

The newer breed of Mack usually requires you to double out and let it drop a good 600 rpm before she'll slide into the next gear. For that reason, I personally hate Macks as I don't want to wait all day for the gears to drop while everyone runs me over.

Eaton-Fuller is, in my opinion, the best tranny on the market and VERY forgiving on errors in timing. Especially the newer models. My own assigned rig is a Volvo with an Eaton-Fuller and she glides along as smooth as silk. Even if I get impatient and drop it in early she hardly ever complains.

If all else fails remember the old adage IF YOU CAN'T FIND IT, GRIND IT!!!

the only 2 stick MACK i drove was a 1987 mack r model. It was a 5speed on one stick and a Lo/High and rev. on another. It wasnt bad at all to drive. You had 5 gears backing up. I got on job site and was shifting gears backing up and other drivers just looked at me like WTF.

I was only 19 at the time and thought i was hot chit. That was a good truck it took its beatings and asked for more. But it only had a 300 in it. So with 73,000lbs on it died fast on the hills.

I can relate to that!!

I had four speeds in Reverse to play with then down shift to a crawl and stop. Had brakes on the driver's side rear tandoms ony. Boss said "use the gears, no need for air brakes with this rig!! :shock: Thanks for reviving those ole memories. :lol: Lots of water under the bridge since then.

OMG!!! I remember those days! LOL what a workout those gave us!

Mackman did you ever drive the Macks with a Maxidine 10 speed? Had everything on the splitter? You could do 50mph in reverse! Man those were the days! Sure glad there over! My 18 speed is WAY easier to drive!

"Never a need to stop & start over." ? If the driver fails to get at least one box into gear when changing both boxes, he will be stuck in neutral. Rule of thumb: the box to be upshifted is shifted first. When you get used to it, you can shift them almost simultaneously.

It gets tricky when skipping ratios on a downshift. The driver has to anticipate what combination he is likely to achieve given the deceleration on the hill.

Seems I never had a problem of that nature.

Shifted 'em with 2 hands all the time which meant both boxes were in neutral at the same time at some point.

I'll stand by my statement that there's never a reason to stop & start over, it's all a matter of rpm's, road speed and shifting into the proper gear.