Gear ratio over drive or direct for heavy haul up to 110K?

When it comes to torque on a driveline the lower the transmission gear the more torque is multiplied. So if you need an 18 to 1 ratio to get moving which is in the vicinity of the direct 10 speed eaton offers as well as the 18 speed how much torque are you really putting on the driveline.


Have you ever seen one twist before it comes out? That's caused by the transmission output shaft moving but the differential input shaft not moving. Another words it took more torque than the shaft could stand to get the load moving. With a low enough gear your right something is gonna move, bend, break, or blister.

 

Yep.... usually when you try forcing 10 pounds of mud in a 5 pound bad, something is sure to come, break, or bleed.

 

Why not just make it a 6x2 while you're at it? Save tons of fuel only powering 1 diff instead of 2.

 

Thing I think you fail to realize is fuel economy is the last thing on a heavy hauler's mind. They simply don't give a #### if they get 4 mpg or 6 mpg. The truck is built heavier to do the job right. Its about having the right tool for the job and being able to depend on said tool to perform well. Lower fuel economy is just the cost of having the right tool for the job.

 

That all depends on cruise speed. Most of us run slow. Too much can go wrong at a higher speed and less time to react. I also know that the claim crazy low rpms, it has been my experience. Low rpms just really don’t pan out tugging on a big pig. Just what I have observed from the trenches.