Ford Powerstroke Diesel Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
149 Posts
Discussion Starter · #1 ·
anyone taken the gears out of a 1 ton and put in 3.73 or 3.55's in them? I think the 1 tons have 4.10 or 4.30 cant remember which one, but at 70 mph i am at 2200+ rpm. I used to have dodges that all had 3.55's and could pull a freight train. A 6.4 should be able to do the same. I know the I-6 has more low end torque than a v-8. thoughts/suggestions.
 

·
Registered
Joined
·
70 Posts
The higher the number (lower gearing) the more grunt you will get. The easier it is to pull or get off the line but it will run at a higher rpm than higher gearing. The lower the numbers (gear higher) all the reverse. Motors works more and less gearing to help.
 

·
Registered
Joined
·
1,763 Posts
My 1 ton has 3.73s...stock.
 

·
Registered
Joined
·
792 Posts
My F-350 dually has 4.10 stock ,I'm gonna put 3. 55 or 3.73 in mine , not sure yet, probably 3.55 , have to change out front and rear because of 4X4. My 4.10 run about 2200 or 2250 rpm at 70 also.
JER-1
 

·
Registered
Joined
·
525 Posts
I have 3.55s but would like to switch to 3.73s. When i pull our fifth wheel just seems to take alot of throttle to get er rollin

Sent from my DROID RAZR using AutoGuide.Com Free App
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #7 ·
The mileage is the reason I would like to swap, but concerned with gettin the load rollin. I was hoping to hear who has 3.73 and what they think about them. I would like to down grade to a 3/4ton, but I got a good deal on my 1ton and dont want to have swap over the dpf delete and other stuff. I looked up gears and they arent ceap either.
 

·
Registered
Joined
·
792 Posts
Just hand cal mine in town driving got 12.6 with the 4.10 gears I'm differenty going to the 3.55 for the fuel mileage.
JER-1
 

·
Registered
Joined
·
49 Posts
I pull campers about 2500 miles a week. the weight makes no difference in my fuel mileage. I have a 2wd with 373's Im deleted with intake and H&S. If I keep it around 65 I get consistently 11.8 mpg. and with no trailer 17.8 everything is filled the same way and hand calculated everythime. Im a little dissapointed with the 17.8 I used to get 15. when driving 4 to 5 thousand miles a week every mpg counts. Ive tried soo many settings and speeds Ive driven myself nuts. Can H&S do KEM tunes? If so would they help MPG?
 

·
Registered
Joined
·
853 Posts
I have 4.10 in my dually, been getting about 13 mpg deleted with H&S.
I did have my rear end apart last month, pinion bearing was out, replaced all the bearings, and reassembled myself. but with changing gearset you will have to check gear mesh and depth and reset all your shim packs to get it all lined up right.
 

·
Registered
Joined
·
769 Posts
If you're driving long stretches, I'd drop the MPH down a few ticks if you don't need to get there quickly. 65 vs 75 is a big difference in aero drag on our trucks. I know you say you stay at 65, but just in case... :) Also, stay out of the boost.

Do you have the taller air dam? How much air pressure are you running in your tires? What size are you tires?

BTW, what?! "Im a little dissapointed with the 17.8 I used to get 15"
 

·
Registered
Joined
·
49 Posts
I drive just about all highway and about 2500mi. per week with no trailer. Do you know how hard it is to keep it at 65 mph with over 600hp and about 1000lbs. lighter than its 4wd brother! LOL I walk Vettes all day long and laugh my *** off while doing it! I hardly ever get the boost over 20psi with a trailer, and ususally around 10 without. Before I deleted I hat it at 30psi for over an hour one day when I was into the wind with a heavy trailer... My first two tanks right after doing the delete I got just under 20mpg, I was pretty excited, they guys at my diesel shop told me with 2wd and being lighter they wouldnt be surprised if I got 22 to 24...nope. If I drive under 60 the mpg goes down, so 60 to 65 is best but there isnt much less mpg if I run 70 to 75....
 

·
Registered
Joined
·
49 Posts
Oh yeah tires are 245 75 17 with 80 in the back and 65 to 70 in the front BF goodrich rugged trail ta, they are very smooth and quiet...
 

·
Registered
Joined
·
792 Posts
Keep this info going for all ,any results ,haven't changed mine out yet hopefully this spring.
JER-1
 

·
Registered
Joined
·
853 Posts
pretty sure I average around 12 every tank sometimes up a little sometimes down, mostly a mix of loaded/unloaded, never seem to run a whole tank one way or the other. and for me loaded means truck + 10-20k trailer, my truck weighs about 9500#'s empty with 4.10 gears.
 
1 - 15 of 15 Posts
Top