2 Stick 12 Speed?

[Lmackattack]

saw a listing for a 12 speed , pics show it has 2 sticks and a air shift cover at the rear. all the 12 speeds I drove had a single stick with air splitter for Direct,Hi,Reverse on the stick and low low on the dash switch.

ever seen this before

[HK Trucking]

Trent, the 2 stick 12 speed was the earlier model, back in the 70's - 80's TRTXL107 IIRC.

The newer one with the air switch on the dash for deep reduction is the TRTXL1070B.

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[Lmackattack]

how do you shift the 2 stick 12 speed? Do you just use the main and split like the single stick 12? then use the aux for low and reverse?

[sbrem]

how do you shift the 2 stick 12 speed? Do you just use the main and split like the single stick 12? then use the aux for low and reverse?

I could be wrong, but I think the second stick is just for the deep reduction gear. I think the splitter and reverse are still air shift on the main stick. I bet Herb knows for sure.

[fjh]

I could be wrong, but I think the second stick is just for the deep reduction gear. I think the splitter and reverse are still air shift on the main stick. I bet Herb knows for sure.

the second stick is the deep reduction

they simply put an air shift on it for certain models!

That made it available in the MH when it came along!

[Lmackattack]

thats what I was thinking... anything to look out for with the older model 12 speeds?

[fjh]

thats what I was thinking... anything to look out for with the older model 12 speeds?

Good trans for the most part! If you do a lot of backing up on steap grades they tend to take out the back bearings We use to replace the bearings once a year in off hyw gravel trucks as a maintanance item, takes about an hour! depending on ptos!

[rhasler]

Here's a shift pattern for the TRTXL107 and TRTXL1070 transmissions.

TRTXL107 TRTXL1070 Shift Pattern.pdf

[theakerstwo]

Good trans for the most part! If you do a lot of backing up on steap grades they tend to take out the back bearings We use to replace the bearings once a year in off hyw gravel trucks as a maintanance item, takes about an hour! depending on ptos!

Do you mean rear brgs like counter shaft brgs?

[Lmackattack]

thanks for this info I may bid on this if the price is right... can you simply add a air shift for the aux box? and remove the stick?

does it take the mack pto that runs off the lower counter shaft?

also is this one of the only mack 2 stick transmissions that has the main stick on the out side?

[fjh]

thanks for this info I may bid on this if the price is right... can you simply add a air shift for the aux box? and remove the stick?

does it take the mack pto that runs off the lower counter shaft?

also is this one of the only mack 2 stick transmissions that has the main stick on the out side?

Answer to Glenns question, yup the countershaft bearings!

answer to Trents question Air shift can convert easy remove the detent ball under the lid and your good to go!

Most have the hollow countershaft for the mack pto but you should look for your self the case is usually stamped with a 0 or pto on the bottom that dosent always mean its there!

Youll like the 12 speed with the exception of the 5 hi lo split they grind a bit! Theres only one or two guys that walk the face of the planet that can shift one with out grinding!

[Lmackattack]

yea I only drove the 100% air shift versions.

drove one behind a 350 and one behind a 300. I like that you can drive it like a 5 speed. or split if you need.

. with the 300 I would start in direct/1,2,3,4,5 then split to hi and go home in OD. I know the grind that you talk about. hard to get use to and know it hard not to..... Im thinking about bidding on it for my RS700L. off the top of your head...What top speed will I have with 4.17s? and LP24.5s. Im stuck at 62MPH/2100RPM right now. Speed limit in IL just went to 65MPH.

[HK Trucking]

how do you shift the 2 stick 12 speed? Do you just use the main and split like the single stick 12? then use the aux for low and reverse?

It shifts the same as the 12 speed that has the air switch for deep reduction, only difference is that the other stick is for deep reduction instead of an air switch.

.

[fjh]

yea I only drove the 100% air shift versions.

drove one behind a 350 and one behind a 300. I like that you can drive it like a 5 speed. or split if you need.

. with the 300 I would start in direct/1,2,3,4,5 then split to hi and go home in OD. I know the grind that you talk about. hard to get use to and know it hard not to..... Im thinking about bidding on it for my RS700L. off the top of your head...What top speed will I have with 4.17s? and LP24.5s. Im stuck at 62MPH/2100RPM right now. Speed limit in IL just went to 65MPH.

Im guessing at 70 with 4.17 having said that. there were 2 versions a direct and an O/D you want O/D I don't remember the prefix for them ya can tell by the number!

[Rob]

It shifts the same as the 12 speed that has the air switch for deep reduction, only difference is that the other stick is for deep reduction instead of an air switch.

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where ya been hiding Herb?

Rob

[MACKS]

I have both versions of this trany,the two stick in my 83 RD behind a 300+ and the air shift in my 96 CL behind a 350,in my opinion the best and most versatile trany mack ever built,you won't use the deep reduction very muck the only time I use mine is when working in front of a milling machine I can creep along at just the right speed so I don't have to ride the clutch just check the numbers on the trany so you know if you have the direct or overdrive,pretty sure the overdrive trany ends with an o,good luck,

[rhasler]

in my opinion the best and most versatile trany mack ever built

I'll second that. I worked on a truck with one that had broken thrust washers in it. The customer didn't want to repair it and it turned out that the truck outlasted the company it belonged to.

[HK Trucking]

where ya been hiding Herb?

Rob

Mornin' Rob.

I've been around, just haven't been commenting that much.

.

[Lmackattack]

TRTXL1070 was the model number... It should be a OD transmission

I checked and if its a .78OD that will give me about 77MPH at 2100 or 65mph at 1700. A little tall geared for a 285 but if I will have more low gears and a go home gear

[Rob]

Mornin' Rob.

I've been around, just haven't been commenting that much.

.

I'm coming back to Sheboygan in the future for more training of interfacing new control panels to existing equipment.

Rob

[HK Trucking]

I'm coming back to Sheboygan in the future for more training of interfacing new control panels to existing equipment.

Rob

Great! Let me know when you're "in town". That lathe is still sitting in the same spot, boss didn't sell it.

[Rob]

Great! Let me know when you're "in town". That lathe is still sitting in the same spot, boss didn't sell it.

I've got to call him to see if I'll need a truck.

I'll keep you informed as I don't know an exact date yet.

Rob

[hillconst1]

A twelve speed is as good as the old two stick six speed but it gives you closer ratios for use with high hp engines that don't have the torque curve of the 237's and 300's. As far as the hi-split to low split grind I found the only thing that worked for me was to pre-select the split right before I moved the shifter and keep tension on the shifter against the far side of the pattern as I moved the lever into 5th gear and for some reason it hardly made a sound. Why, I haven't got a friggin clue I discovered it by accident. This transmission works great behind an E9.

[Packer]

I found a 12 speed with an air splitter.

Rather have a two stick set-up.

Still in the works but a trade might work for both of us!

Packer

[Guest 45LMSWM]

I found a 12 speed with an air splitter.

Rather have a two stick set-up.

Still in the works but a trade might work for both of us!

Packer

I agree. I've driven both and the 2-stick 12 speed is much more comfortable to drive in my opinion. Reaching up to the dash to shift out of low range doesn't feel natural to me. Running a lowboy, I used the deep reduction all the time. (Boss would've had a cow if he found out you weren't using it.)

Again, great trans. Ran them with E6-350s and E9s. Even better for backing up!!!

-John