Shifting a 5x4 twin stick tranny.

[Jeff D.]

Have any of you operated a truck with a twin stick 5x4 tranny?

I just purchased an International tandem dump truck with that transmission set-up.The person I bought it from said he never used the secondary in super low,or low.He'd start out in first in the front,direct in the rear.Run up through the first five,and then bring the secondary into overdrive.Is that the proper technic?Have the rear in a low enough hole,so that the truck can pull it with the front in first,run up through the front five,and then run the secondary up until you get to the desired road speed?Or is there a different way,which could use all 20 gears progressively?

My grandfather had an old Mack that had a twin stick.It was called a tri-plex,or a quadra-plex,or something like that.That one required three arms to shift properly.I'm hoping this one won't be as complicated to shift right.

Thanks for any help.

 

[Dwan Hall]

5 & 4 is a lot of fun to drive, or at least I think so. I have a 1963 REO 3 axle dump and just love it.

Empty I start in 2nd and drive, then 3rd 4th then 2nd and od, 3od 4od then 5thod

loaded - 2nd low,3rd,4th 5th, - 2 drive,3rd 4th,5th - 2nd od 3rd, 4th, 5th

only time I have ever used compound low is if starting hp hill with a load or in soft dirt. 1st and compound low top speed is about 4 mph at 2000 rpm and top speed is about 65 mph @ 2000 rpm my working range is between 1800 and 2100rpm not bad for a 43 year old truck.

after a little while you will find your own combination but this works with the 180HP cummins and my dump.

 

[Steve Frazier]

Just don't miss a gear!!! If you do, just stop the truck and start over, there's no getting it back, especially if both tranny's are in neutral. You stick one arm throgh the spoke of the steering wheel when you need to shift both levers at once, pretty tricky and you need to plan ahead for no abrupt turns while shifting.

 

[Jeff D.]

I picked the truck up this morning.It was a long 35 mile ride home with not being familiar with the shifting.The third and fourth in the secondary,being reversed in location,and having to move both levers for the next gear,every other gear wasn't much fun at all.

The truck has a DT466,and the operating range seemed narrower than I expected.It lost all it's "pull" below 1800rpm,so shifting the front up one gear without dropping the secondary down one was too big a jump for anything but flat ground.

If there was anything "good" about it,it was that with both in low it was very slow,and when I finally got it into the big holes,it had a higher top speed than I'd ever need.

I ended up having to shift it(being mt) 2 direct-3 direct-3 over-4 direct-4 over-5 direct-5 over.So it ended up with seven shifts when running mt,like you had Dwan,although in a different sequence.In this truck the secondary acted like a splitter,rather than a range select like yours does.I supose the ratios in each transmission aren't always the same when the two transmissions are matched,giving a different process for getting the next closest gear.

Thanks for the advice though,hopefully I'll get to thinking it's fun also,someday!

Steve,I'm going to do my best NOT to get both levers in neutral at the same time,although in the rush to get up to speed when pulling out in traffic the wrong lever may get grabbed by mistake. :eek2 Time will tell.

 

[Ford LT-9000]

If the truck is in good shape and worth spending some money on get rid of the 5+4 set up and go with a 13spd it will make the truck nicer to drive.

Old twin stick trucks is old and obsolete usually those trucks are underpowered and light gvw. Most of the twin stick trucks ran gas pot engines the rear diffs are in the 34,000-36,000 and the heaviest in those trucks was 38,000lb rears. Light rear suspension they were basically a upgrade over a single axle.

 

[x26pfw]

Shifting a 5x4 tranny

First post bear with me... 1979 I was taught how to drive a twin stick... when the truck was empty instructed to start off in 2(main)-2(auxiliary), up-shift the aux into 4th and then put the aux into neutral and shift the main into 3rd and then put the aux into 2nd... to down-shift I was instructed to shift the aux first into 2nd and then shift the main into the lower gear... thats the way the owner wanted it... talking and riding with the other drivers, some would shift both sticks at the same time with the arm through the spoke of the wheel and some would shift both at the same time with their left forearm on top of the wheel while twisting their torso a little bit to the right... one of the drivers said what happens if you hit a pothole when your arm is throught the wheel... I never tried it through the wheel after that...

 

[Jeff D.]

LT9000,as much as I like the 13 speed,the truck isn't worth the expense.It's a 1979 S1954 International.I'm not expecting to do alot of hauling with it,so as long as it can pass the yearly inspection,I'll just replace the stuff that breaks,and do regular maintanance.If the truck was alot newer,and had less wear all around I might entertain the idea then.It did just get the main transmission rebuilt,which is the reason I had to wait to pick it up,so that should be good for a while,atleast.

Hello x26pfw,it's nice to see another new member.The way you described may work for me too.I'll get more practice come summer,and get to experiment then.