Transmission for twin stick shifting

[truckabilly]

If I want to build a model truck with two shifting levers in the cab, what transmission do I need? Are two separate gear boxes in the frame or are they joined together in one block?

I´m talking about 1950´s Peterbilt. Can somebody tell me what transmission I should look for? A picture would help a lot.

Thanks in advance.

Jarda

[ap40rocktruck]

Well the answer is rather long & somewhat complex. if you are looking to use the 4x4 married box spicer that came in many of the AMT kits such as the Diamond Reo, Western Star or Road Boss, then both sticks would be fairly close together in the cab & that transmission can be detailed up quite nice.

If you are looking to use a 5 & 4, then the 2 transmissions from the AMT KW W-900 / Alaskan Hauler . Challenge mixer & the T-600 is what to use. All of these kits share the same chassis & drive line (of which as we know is totally wrong for the T-600). For that installation, the 5 speed main box is mounted to the engine & the 4 speed auxiliary box is mounted about 2 to 3 scale feet behind the main. Linkages are separate to each transmission. I will look in my files and see what i can post for images of each set up.

Ap40

[truckabilly]

Thanks a lot, Richard, for your answer.

Now I have another issue to solve. Peterbilt 351 could have the steering box located inside the frame or outside. My version has the inboard box but... I have never seen one. I have no idea what lines should be connected with it or if I need a ram also to provide the power steering. The set up in the picture is the one that inspired my model. Can somebody explain for me how these old systems worked, please?

[lapazleo]

Actually the 16 speed spicer in the old AMT kits is the SST16 also known as the 4x4 airshift. It shifts like a road ranger 4 speeds gone through with 4 ranges shifted by air with a range button. There was also 10 14 and 20 speed version. The 10 speed shifted like a Fuller super 10. Other than resin the AMT 5 x 4 from the w900 KW and its variants are it. The Alaskan Hauler used the 16 speed in place of the original 5x4 even both set ups are in the kit.The sticks in the kit are incorrect.

[truckabilly]

Well, got the aux gearbox now. Can somebody tell me why there are two linkage rods coming in the box? And where are the other ends of them? Are they running from the same stick?

[Force]

Both rods from the aux gearbox goes to one of the two sticks in the cab, the other stick is for the main gearbox.

Edited February 8, 2014 by Force

[mistermodel]

Jarda,the 2 linkages would move 2 shift forks in the transmission. I suspect for durability and maintenance. The other end they would go to the secondary shifter.If something wears out its easier to fix the shifter than the transmission

[rctruk]

One way to think about shift linkages in a truck with a 5X4 set up is that the trans connected to the bell housing has the shifter mounted on the top of the trans and there is no visible linkage. The other trans mounts behind the main trans....usually connected by a short driveshaft, has an external linkage connected to its shifter. In the cab the shifter for the main trans is closest to the driver and the aux. shifter is to the right and maybe a bit behind the main shifter. At least that is the way it was in all the ones that I have driven.

[truckabilly]

Thank you all for explanation. Not being truck driver myself I always appreciate this kind of info.