Ihc 9400 1995 cummins n14

That's a very unusual combination. Road tractors rarely have that low of a gearing, if you are saying that your ratio of the rears is .444.

The first thing I would ask you is are the rears that are in there in good shape? Would you rely on them for the next however many years?

The next thing that I would suggest his get under the truck and see if that is an overdrive transmission or not.

If it were me and your engine is only 370 horsepower and the rears are good I would probably check with Eaton to see if you can buy a double Overdrive transmission if that would gear you high enough.

The reason I would concentrate on changing the transmission is because if the truck is geared that low you probably will be able to pull really well with the lower horsepower. But you need the overdrives to be at the right speed in the right RPMs.

The road Rangers site has a calculator that helps you to figure gearing and overdrive with Road speed and RPMs.

There also are formulas online they will show you how to figure that for yourself with your tire size and Revolutions, etc.

The only thing is if you trade your transmission for a double overdrive I don't know what kind of a credit they will give you because you're not changing transmission like-for-like.

But I would call them I'm sure that they can help you to figure things out etc etc

Some other guys might have a different idea about it but if I had a truck that was geared that low I would enjoy the low gearing and being able to be geared low in reverse and have a low gear to pull out in, as long as I could cruise at the right RPMs. And given that your motor has less horsepower I think if you swap the rears you would feel that it would be more sluggish.

That's the way I see things anyway.

 

And just on another note. I knew a guy many years ago that had a tri-axle dump truck that was geared incredibly low. He only had a 270 or 290 Cummins in it.

He put at least a double overdrive Transmission in there and wow that truck would fly wayyy past the speed limit and Beyond. It surprised me. I think I was doing about 90 when I realized I was actually doing 90 and slowed it right down. I thought that was a good move he did.

Just like you were saying that truck in particular would really only roll around 50 or 60 miles an hour flat out wide open.

 

His was a 13 speed with at least double Overdrive.

But you would have to call eaton and discuss all that with them. There probably is a particular model of a 13 speed, but there's probably a certain model that the steps and the ratios are better suited for your particular engine and horsepower and torque.

That's what the ABC designation is after your transmission numbers. For example RTX 14610 C. The c gives you different steps than the a or the b.

But if you call Eaton I'm sure they'll be able to help you get the right specifications and configure the right transmission for you.

They should be able to give you all of the technical help that you need.

 

Cool.

Just watch you don't get any speeding tickets, LOL

Good luck buddy

 

On same page with think it is dino soar. Also you may want to check out putting what most call "a back half" on transmission. Its going to make a 13sp out of the 9 speed. Most transmission shops can do this. Its not a cheap add on it is what a 13 is like from factory. The back half makes your 9 sp slightly longer so they will shorten driveshaft, and put new shifter knob in cab as now will be a splitter on it. I did it to a 1981 cabover i had. Made a truck out of it. Right now i have a 10 sp in a 01 379 and shop told me can't do back half on this 10sp as its a metric eaton. Cleaned off id tag. Yup its eaton 10sp made in France. Why people buy or order a semi trk with 9&10 speeds ? Been thinking of putting a 13 in my trk now.