history of truck transmissions

History of Truck Transmissions: Twin-Sticks to No-Sticks

Modern truck drivers don’t realize just how good they have it. Trucks have undoubtedly come a long way, with the experience getting better with each newer model. Trucks have evolved from seats with no suspension to air-ride seats, from no-heater and air conditioner to climate control, and from the twin-stick transmission to no-stick. Today’s trucks are Cadillacs in every way as compared to their predecessors, for instance, the 1957 B61 Mack.

About the two-stick transmission system

How the two-stick transmission system worked

The twin-stick transmission was a manual transaxle transmission developed in the 1970s that was famous in most trucks and company vehicles of that time. It had eight forward speeds in a 4×2 arrangement. The transmission was mounted below the engine, which meant that the gearbox needed to take power down from the clutch. Doing this directly was impossible because the gearbox would have to rotate in the opposite direction from that required. Therefore, an extra shaft was needed, which was later modified as a separate 2-speed gearbox. It contained the auxiliary shift lever and the main shift lever mounted in the cabin.

While operating, you would need to switch the first gear on the main box low, then to high on the auxiliary. After that, you would shift the main into second and pull the auxiliary out of high before engaging the clutch. Next, you would rev the engine, slip it into low and engage the clutch to get into second low. You would have to repeat the same process depending on the load until you get to top speed. It was possible to run through a few gears at low before splitting them. If you missed a split shift, you would wind up in what was known as “double-nothing” with both transmissions in neutral. This would mean stopping entirely to get the truck back into gear.

Challenges of the Two-Stick transmission

The main challenge was shifting the gears back and forth. Sometimes the truck would go off if you missed a split shift, which can be dangerous, especially at high speed.

Additionally, it wasn’t easy to operate the two-stick transmissions while still controlling the steering wheel simultaneously. You would often see drivers with one arm gripping a shifter while wrenched through the steering wheel while the other arm grapples with the other stick. If the driver happened to hit a pothole at that moment, it would be possible to break their arm as the steering wheel could whip around.

Don’t look back – Go forward with new-model, automatic-transmission trucks.

The new-model automatic transmission has long replaced the two-stick transmission. The two transmitters are bundled together in the same box, with the two gearshifts replaced by the shift lever and a hi-lo range selector, roughly equal to today’s 8- or 10-speeds. The new automatic transmissions are lighter and more compact, lowering the vehicle’s fuel requirement. Additionally, their gear tooth surface has a lower coefficient of friction when the gears engage.

If you have been looking to work with the new-model automatic trucks, Duncan and Sons Inc. in Arizona is the place to be.

Who do we hire?

At Duncan and Sons Inc, we are Arizona’s largest intermodal/ drayage carrier. We have been working in the port of Long Beach for 80 years, so you can be sure we are good at what we do. We have over 300 trucks and  we hire 10-20 drivers per month to keep up with the growth. We hire experienced drivers who are 22 years and above and with a valid CDL.

Benefits of working with us.

When working at Duncan and Sons Inc, you will not only be driving the best new-model automatic transmission machines; you will also get to enjoy the following benefits:

  • A monthly productivity bonus
  • Health, Vision and Dental Insurance
  • Life Insurance sponsored by the company
  • Voluntary Life and Short-term Disability
  • 401(K) with employer match up to 100%
  • Per Diem
  • Paid vacation
  • Paid sick days
  • Quarterly Safety Bonuses

Apply to work with us today

Are you ready to join the Duncan and sons team in Arizona? Check out our open Class A Driver position here. CDL A Driver Positions. If you already have your TWIC card, enjoy a $500 sign-on bonus.  

Featured Image: General photographer/Shutterstock

Leave a Reply

Your email address will not be published. Required fields are marked *