Swapping Detroit for CAT or Cummins

Not to sure. I'm not well knowlaged into gears. All bout power to weight

 

question was posed to @benjamin260_6

 

First you have to be specific on which 13 speed. Second, go to Eaton's website and look up the gear ratios for the transmission in question. Finally, get your calculator out and start multiplying. The math is so simple, even a self proclaimed stupid person could figure it out.

 

@wore out can’t tell you anything so I don’t expect I could either. I wanted you to show yourself how many gears you had to drop with with that tall rear gear every time you climb a hill with a 3406 or DD60. Bench racers know a lot on the internet.

 

I know what you were trying to do. You can't convince me a truck will pull better if you gear it up at the transmission than back down at the rearends. You guys keep saying it won't work to run in direct and have a higher rearend ratio but there's already thousands of trucks doing it an proving you wrong everyday so keep on typing and show what you don't know.

 

The question stands....if you hit the bottom of the hill in high gear how many would you drop?

THAT is why everyone (except you) says those gears can’t pull a hill. In your fictional mind you said “start in a lower gear at the bottom” to get the final drive ratio you need. LMAO that’s going to play well on I-95.

In the real world of speed limited trucks you hit the bottom as fast as you can and drop them fast or by twos and threes trying to stay ahead of the falling tach while the truck is falling on its face after every downshift until you finally get the right gear.

Oh by the way.....all those trucks you speak about.....are doing it with automatic transmissions and new engines with broad torque curves because the drivers aren’t good enough to pull it off. I would love to see you pull a grade with 2.76 rears behind a B that lives between 1600 and 1800. You’d go through a pair of fingerless gloves every week

Tell me I’m wrong

 

Your wrong.

You would just be pulling the hill 2 gears lower in the transmission vs a truck with say 4:11 rears. Still same amount of shifts. Still go up the hill same speed.

You would be in the low side transmission way more often with the 2.76 rears thou loaded heavy.

 

Yep gotta drop more gears which is Exactly what I said.

Now please explain how two gears lower is the same amount of shifts unless you’re lugging the engine and dropping multiple gears at a time

 

You already hit the hill 2 gears lower because your running in direct.

So same amount of shifts overall

 

I drove a Very High HP Cummins in the late Mid to late 90's that was turning a set of 3.55's rears that had a Double OD 13 speed transmission. The final was .5 to 1 in 13th gear. My direct drive gear was 10th gear also. That truck could pull a hill in 10th gear faster than a striped ape with a cattle prod up its rear end in 10th than any truck geared taller. Why it had the HP and torque to do it. I routinely climbed hills at road speed in that truck in 10th gear under 60K gross. She had the guts to flatten the hills.

The tester I drove spent more time pulling mountains out west than I care to remember. My fuel stop in Wyoming was the Pilot in Laramie not the best place to get a run up on Sherman. Yet that tester would be doing 70 MPH by the time I got to top of the hill. She had 3.73 rears transmission was a stupid 10 with a .73 OD in 10th gear. The worst pulling trucks I drove where the ones from Millis. They had 2.70 rear ends in them gear bound from hell and could not pull their way out of a mudpuddle. The same hills that I could pull at full speed in that International 2 years prior I was down to under 30 MPH thanks to how Millis Set up their trucks.