Twin Stick Transmission Shift Patterns

[ThaddeusW]

I have never had the oppertunity to drive a twin stick mack transmission and I was wondering how they are setup. For example I have herd that the basic setup is a 5 or 6 speed main and a hi-lo-reverse secondary. Is the hi-lo ment to split the gears? Also is there any online info on the different mack twin sticks and diagrams/pictures/instruction on the shift patterns? How does one shift progressivly through the gears?

I saw one mack on ebay that had a real weird shift pattern that loked like an incomplete H shift pattern like this :

gear - gear - gear

xxxx- gear - xxxx

(it was one of the two shift patterns and you could not really see the other pattern for the second stick)

Thanks!

[Lmackattack]

a 2 stick 6 speed is realy a 5 speed with the option of a low first gear for extream off road or heavy hauling.

the main box has 5 foward gears

the aux has revers, Low and direct

under normal use . you only shift the main stick (closest to your leg).1-2-3-4-5 the aux box stays in "Direct"

If you are very heavy or in a hole and need to climb out you would put the aux or compound box into "low" and use the main in 1st. After the truck is out of the hole mud etc...and on flat level ground you would shift the aux box from "low" to "direct" accelarate then shift 2-3-4-5 with the main. So basicly its like splitting 1st gear in half with the aux box. this gives you 6 foward speeds. However the shift from "low" to "direct" has to be done carefully as if the truck is still climbing out of a hole you likely will miss shift as the slow road speed will fall very quick.

I always let the truck get on flat ground bring the RPMs to 1600 or so and then make the shift.

A B model with a 20 speed or 18 speed depending on what you want to call it "Quad box" shifts diffrently

Its been a few years but I remember it like this

the main. ( farthest from your leg). has 5 positions for foward and 1 for reverse

the aux or compound box has 4 positions low low,low split,hi split, direct

you start with

Compound in low low/main in 1st

shift main 2-3-4-5

grab both sticks/ move compound to low split and the main stick to 1st

shift main 2-3-4 dont use 5th

grab both sticks/move compound to hi split and main stick to 1st

shift main 2-3-4-5

grab both sticks/ move compound to direct and main stick to 1st

shift 2-3-4 dont use 5th

I dont know why you cant use 5th in direct and low split but I heard the gears are spining to fast of the ratios are so close its useless to use those gears

Trent

[Superdog]

Hate to argue with someone that's put as many miles on a B as Trent,but the proper way to shift a 2 stick Mack trans,is like this.

You split the aux. for each of the main box gears,not as Trent said.

For a Duplex,start with the main in 1st,aux. in low,then split to hi,then 2nd low,2nd hi, etc.

for a Triplex,1st in main,aux. in lo,then direct,then hi,2nd lo ,direct,hi,etc.

The Quad is the exception in the lo-lo split only,he did have that right.

In lo-lo you can shift up thru each of the main gears,but unless in severe conditions,these aren't used much.Otherwise you shift it just like a Triplex,1st lo,direct,hi,2nd lo,direct,hi,etc.

The 13 speed Triplex and 18 speed Quad were considered double over transmissions and in 4th hi,you could shift directly into 5th hi.

[Superdog]

one more important thing I forgot,don't get both sticks in neutral at the same time,unless you are stopped.

[Lmackattack]

"Its been a few years but I remember it like this"

but thanks anyways for clearing it up

[Packer]

Superdog,

You may be trying to be a nice guy and not confuse Trent, but once you get the hang of it, both sticks can and have been in neutral when going from 4 low to 3 high, 3 low to 2 high, etc.

Thought that's why there are two sticks - - - One for each hand!!! LOL

Hope to see you in the spring, Superdog!

Till then, keep a clutchin'!

Packer

[Superdog]

Garth,

Guess I should have added "till you figger out what you are doing",but I think in this case I was safe in leaving it off.

[b61fred]

HI

The gear you get when both sticks are in neutral... double nothin' usually when I find double nothin' I just have to stop and start over. Ha Ha

Fred

P.S. I think everyone has hit double nothin' a time or two.

[Freightrain]

Fred, if you get both in neutral...just slow down a bit til you can slip main back into a gear. Then rev motor a tad and bump compound back into a gear.

I used to get caught when I first bought truck. Getting into 5th lo going too slow would leave me coasting. I could coast til getting main back into 4th, then bump throttle and drop compound back into OVER(or what I could find). Then proceed. It only takes a few times to fig'r it out and been a few years since I had that problem.

Been practicing the two hand routine now. Pretty good at it...but ain't brag'n. The hard part around here is finding a road SMOOTH enough to actually feel comfortable letting go of wheel and sticking arm thru!! Withoug getting arm broke at elbow from wheel coming around from hitting chuckhole!!! OUCH!!

Funny thing....when somone posted my drivin' video on Hank's site, someone over there told me that you DON'T use the compound like I did(like Mike stated). That he was an "expert" and I should learn to do it right....

[twostickmutt]

in the "good ol' days" there was many a left arm bruised or broken from going through the wheel and that's first hand. one night a 1952 DC99 A-CAR bit me pretty hard. BUT THAT'S WHAT I GOT FOR DRIVING AN AUTOCAR!

[Packer]

The 1958 'B' 63 that I first drove (back in 1961) wasn't going fast enough when you made the shift to 3rd over from 4th to worry about banging any body parts!! LOL

The truck was geared for 62mph topped out with a triplex. At the time I thought I had the world by the tail!

Hadn't drove a Mack after '67, when the boss came up with a new '67 KW, until I drove 'Aunt Bea' home last year. Had a great time with that Baby Quad for the 45 miles I needed to get her home.

Packer

[Superdog]

Fred, if you get both in neutral...just slow down a bit til you can slip main back into a gear.  Then rev motor a tad and bump compound back into a gear.

I used to get caught when I first bought truck.  Getting into 5th lo going too slow would leave me coasting.  I could coast til getting main back into 4th, then bump throttle and drop compound back into OVER(or what I could find).  Then proceed.  It only takes a few times to fig'r it out and been a few years since I had that problem.

Been practicing the two hand routine now.  Pretty good at it...but ain't brag'n.  The hard part around here is finding a road SMOOTH enough to actually feel comfortable letting go of wheel and sticking arm thru!!  Withoug getting arm broke at elbow from wheel coming around from hitting chuckhole!!!  OUCH!!

Funny thing....when somone posted my drivin' video on Hank's site, someone over there told me that you DON'T use the compound like I did(like Mike stated).  That he was an "expert" and I should learn to do it right....

←

Larry,

You need to eat a little more,then you don't have to worry about taking both hands off the wheel to shift.The time I met up with Aaron Tippin,he mentioned the fact that he didn't quite have belly enough to do any fancy 2 handed shifting in his B's.

As far as the "expert's" comments you mentioned,maybe it was somebody Trent coached.

[b61fred]

OUCH!!

[ThaddeusW]

You know I thought the twin stick with the hi-lo-rev was the predecessor to the 12 speed. So you can't use any other gear other then 1st in lo? And thatnks to everyone for explaining the quad box for me. I had a feeling that you used the comound to split the main gears.

Just in case one day i need to drive one i want to be shure i have it down:

a quad with lolo-lo-direct-hi compund is shifted like a 15 speed splitting each gear with lo-direct-hi correct? and with the compund in lolo you can progressivly shift 1-5 for a deep reduction range correct?

a 2 stick 6 speed is realy a 5 speed with the option of a low first gear for extream off road or heavy hauling.

the main box has 5 foward gears

the aux has revers, Low and direct

under normal use . you only shift the main stick (closest to your leg).1-2-3-4-5  the aux box stays in "Direct"

If you are very heavy or in a hole and need to climb out you would put the aux or compound box into "low" and use the main in 1st. After the truck is out of the hole mud etc...and on flat level ground you would shift the aux box from "low" to "direct" accelarate then shift 2-3-4-5 with the main. So basicly its like splitting 1st gear in half with the aux box. this gives you 6 foward speeds. However the shift from "low" to "direct" has to be done carefully as if the truck is still climbing out of a hole you likely will miss shift as the slow road speed will fall very quick.

I always let the truck get on flat ground bring the RPMs to 1600 or so and then make the shift.

....

Trent

←

[b61fred]

Sounds like you got it down, Now for the double clutching.. that was the hardest thing for me to learn, I have found the triplex was easier to learn on than the 9 speed duplex, the gears ratios were closer together than the 9 speed.

Fred

[twostickmutt]

Sounds like you got it down, Now for the double clutching.. that was the hardest thing for me to learn, I have found the triplex was easier to learn on than the 9 speed duplex, the gears ratios were closer together than the 9 speed.

Fred

←

after a while you'll forget the clutch is even there except for takig off

[Packer]

Since this horse hasn't quite died yet, I'll jump back in.

I lerned to shift with the clutch. The reason given was that by using the clutch just as the gears meshed took the load off of the gear train and therefore eased the stress on the transmission. After many many miles

(over a million) I still find that the clutch gets used a whole lot.

I did loose the clutch push rod on one trip and got home just fine, but I had too many miles to change, and went right back to "Double clutchin'" just like I had a lick of sense!

Keep a clutchin!

Packer

[twostickmutt]

to each his own packer. after over 2 million miles i still don't use it much and haven't hurt a tooth yet. like i said......to each his own. j.j.

[Freightrain]

I have a friend who I was going to let drive the ol girl. He got in the seat and realized even with it cranked all the way down on the bottom stops...........his belly was still wedged tight on the wheel....LOL!!!

Guess he loses out...LMAO!!!

Sometimes I just lift my left leg up and hold the wheel too, like I do in my pickup. Since I don't use the clutch unless the gears are wound too tight to let go without bumping it. As long as the gears DON'T clunk when shifting...it does not make a matter if you use the clutch or not.

My truck is geared for 65 mph, so I'm in the same basic game with my triplex. Heck 5/lo is only at just over 35 mph!

[Superdog]

You should see me behind the wheel in one of my concave cab B models,Larry.

[twostickmutt]

I have a friend who I was going to let drive the ol girl.  He got in the seat and realized even with it cranked all the way down on the bottom stops...........his belly was still wedged tight on the wheel....LOL!!!

Guess he loses out...LMAO!!!

Sometimes I just lift my left leg up and hold the wheel too, like I do in my pickup.  Since I don't use the clutch unless the gears are wound too tight to let go without bumping it.  As long as the gears DON'T clunk when shifting...it does not make a matter if you use the clutch or not.

My truck is geared for 65 mph, so I'm in the same basic game with my triplex.  Heck 5/lo is only at just over 35 mph!

←

hey freighttrain. they were called steering wheel brakes. when i'd get finished from a run with the b model there'd be a nice black line on my t-shirt where the wheel rubbed all night. guees we had steering wheel brakes long before engine brakes. j.j.

[HeyCharger]

Hate to argue with someone that's put as many miles on a B as Trent,but the proper way to shift a 2 stick Mack trans,is like this.

You split the aux. for each of the main box gears,not as Trent said.

For a Duplex,start with the main in 1st,aux. in low,then split to hi,then 2nd  low,2nd hi, etc.

←

Sorry Superdog, but I agree with Trent on shifting a Duplex.

You leave it in low until out of the hole, then shift to direct and shift up all in direct.

Here are the ratios for my tranny;

2 Stick Duplex Transmissions With Low Hole TRDX-720

Gears .. 1st- 2nd- 3rd- 4th- 5th- Rev

Direct 5.45 3.12 1.75 1.00 0.78 5.45 (Compound Ratio 2.38)

Low 12.97 7.43 4.17 2.38 1.86 12.97

With TRDX boxes use LO and shift main box until vehicle negotiates hole, then use HI and main box as required. If vehicle is out of hole at 3-L, shift to 2-H per arrow, etc

As you can see by these, if you were to change from say 3rd direct to 4th low, you would in fact be changing DOWN not up.

Rod.

[Packer]

to each his own packer. after over 2 million miles i still don't use it much and haven't hurt a tooth yet. like i said......to each his own. j.j.

←

Exactly!!! Some go with, some without, and I'm sure there are a few in the middle.

I'm sure that depending on the teacher and the way he (or she) did it, has alot to do with how we do it now. The intent is to get from point 'A' to point 'B' (pun intended) as best as you can.

Have a good one!

Packer

[Admiral]

Thought I'd fire this thread up again, since I am a newbie and you folks have a wealth of experience.

My bulldog (R600ST) has a 5X3 Triplex, and since I don't know the gears yet, I didn't know what the progression was. But let me ask this, if you are running empty (I have a dumper) do you have to use all three ranges? When I drove the truck home for the first time, I just left the range in Direct, and shifted a normal 1 - 5 pattern. A little double clutching was all I needed, and she ran fine.

[twostickmutt]

Sorry Superdog, but I agree with Trent on shifting a Duplex.

You leave it in low until out of the hole, then shift to direct and shift up all in direct.

Here are the ratios for my tranny;

2 Stick Duplex Transmissions With Low Hole TRDX-720

Gears ..  1st- 2nd- 3rd- 4th- 5th- Rev

  Direct  5.45 3.12 1.75 1.00 0.78 5.45  (Compound Ratio 2.38)

  Low  12.97 7.43 4.17 2.38 1.86 12.97

  With TRDX boxes use LO and shift main box until vehicle negotiates hole, then use HI and  main box as required. If vehicle is out of hole at 3-L, shift to 2-H per arrow, etc

As you can see by these, if you were to change from say 3rd direct to 4th low, you would in fact be changing DOWN not up.

Rod.

←

better check and see what a real DUPLEX is. i think you're getting your two sticks mixed up.