I have a 2005 ford ranger it has a 4:11 and I have a 3.0 v6 engine. I have 31x10.50 tire on the back and 15 in rimes. I am wanting to change to a 3:55 or 3:73 ring gear. This should help my gas milage should it not. When i am running at 60 mph I am turning about 2200 rpm. can someone help with what size ring gear I need to change to.

 

You're going to drop about 400 RPMs going to a 3.55:1 gear. You should be turning about 1850 rpm at 60 mph with a 3.55 gear. I think a 3.73 would be a better comprimise just to keep the motor from bogging down in 5th gear at lower speeds. Keep in mind that you probably won't pick up but 1-2 mpg from going with a taller gear, unless you made a real big jump to something like a 2.73:1, which would make 5th gear useless on anything but the highway.

 

bart99gt I have a auto od transmission in this truck

 

Correct me if i'm wrong, but just cause you're turning less rpm's doesnt really mean your using less gas. I would say that unless you get junkyard gears, and install them yourself, the difference in gas mileage you might see wouldn't pay for the gears. If you figure a gearset costs about 200 bucks, and the setup kit might cost around 50, and maybe some new bearings might be more, then if you have a shop do it, i guess it can cost upwards of 1000$. Lets say you do pick up 1 MPG with the gear change, so lets say before you were getting 15 mpg, and now your getting 16, well, a 300 mile trip would cost you (300/15=20 gallons x 2$ a gallon)= 40$ Then with the new gears going 300 miles would cost you (300/16= 18.75 gallons x 2$ a gallon)= 37.50$ with a total savings of 2.50$, it would take you a total of (1000$/2.5= 400*300)=120,000 miles before it woudl even pay for itself, That is considering if you drive all highway, now with the 3.0l engine and 31x10.5 tires, stepping down to a 3.55 gear ratio may have a negative effect on your in town mileage also. So while you may gain highway mileage, you may loose city mileage. i'm not trying to tell you what to do, just trying to give you the other side of the story. If i were you, i would personally leave the 4.10's in, because when you put in 3.55 gears, i bet you any money the truck will feel alot less powerful. Now if you want to do this, i would personally go with the 3.73's and also throw a L/S carrier in there, and call it good. But thats just me, hope this helps with your decision. Also, WELCOME TO FTE!

 

Usually it shouldn't cost more than $350-400 to buy a set of gears and have them installed. A new large pinion bearing might run another $12-13. FMS gears come with a new pinion nut and crush collar. Most places that do enough gear installs won't even charge you for a shim pack as they usually have some left over from past installs.

I think all the new automatics are of the 5 speed variety in the Ranger.

 

I agree with Peter, new gears in order to save $$ is a pie in the sky. A new ring and pinion in my explorer was a 1500$ job ( at a dealer, granted). Luckily it was warranty work. Also with that little engine and big tires, you will feel it. You possibly could accomplish your goal by getting even Bigger tires if they would fit. That would be cheaper.

 

$1500!?!?? Its just an 8.8" rear for crying out loud!! Warranty or not that was way to much money. I've seen an experienced mechanic swap gears in an 8.8" in about 45 minutes before. Of course I forget that Ford's "service" gears are about triple the price of the Motorsport parts, even though they're the exact same parts.

The first place I had gears installed was at a dealer, final tab, including all parts was about $375.

 

yeah, which is why i love junkyard, i could probably get a gearset for under 100$, i bet i could get it for 50$ at this one small town junkyard. Also, MYLESBREWER, is your truck 2x or 4x? If its 4x then you have to get new gears for the front also. If its 4x you might be better off going with bigger tires like originally posed above. Yeah, changing the gearsets in an 8.8 is almost as easy as changing engine oil. That is if you have all the tools to set the backlash, etc.