I have been looking for transmission gear ratio specs on line at various manufactures websites. I am not having much luck so far.

What I am trying to do is find a transmission that will let me cruse along in my motor's happy place (1450-1500 rpm) at 55,60,65,70 and 75 mph.
the motor is an isx 475 hp. I have been thinking an 18 speed direct final type transmission would fit the bill for me.

I drive west to east coast and back pulling either 53 ft dry van or reefer so I see lots of variation in terain and legal speed limits.
I realise that nothing will prolly be a perfect fit. but I would like to come as close as possible.

 

Go to www.roadranger.com then go to the road speed calculator and plug in the ratios to see what you'll need to get the desired result.

 

Thx muchly for the link to the calculator.
apreciate it.

 

Well acording to the calculator , running 22.5 LP's with a transmission ratio .73 & rears 3.25 I should see 76 mph at 1500 rpm.
I have also found the spec sheet's on all of eaton/fuller transmissions. so looking at all the various shift patterns it appears to me that an 18speed is overkill. A thirteen speed seems more like the way to go to me.
on truck paper I see a lot of Kenworth W900's with these specs.
Is anyone outhere running a truck with this setup ? how do you like it ?

 

I won't bump this again.

Any one useing a 13 speed transmission with a .73 final with the rear's being 3.25 ?

do you like this setup ? do you think something else would be better ?

 

With todays prices I don't think 3.25s are a good option because you basically always have to run fast with those gears.