Axle Ratio Question?

[flya727]

I just picked up my 03 ST last month and love it. Had a 95 Ranger for 12 years and many things are familuar with this truck, just more power with the ST. I just found out that my ST has a 4.10 rear end.

I know this will give me more torque while pulling, but I assume i will loose some MPG also on the highway? Anyone have some rough numbers on what you gain/loose with the 4.10? Also, was this ratio an option or part of a type of package that Ford offered?

Thanks everyone!

Rick

 

[briwayjones]

I don't think it was part of a special package. You'll probably loose a mpg or two. If you wanted to you could put larger tires on it which will gear it higher. But you'll loose some of the torque.

 

[JohnnyO]

Basically Sport Tracs with 235/75-15 or 235/70-16 tires came with 3.73 gears and ones equipped with the larger 255/70-16 tires came with 4.10 gears, so the rpm vs. road speed will be about the same.
Mine has 3.73's and I put on 265/75-16's almost immediately. It loafs at about 2200 rpm at 75 mph but I still get 20 mpg at best on the highway. City mpg still sucks.
I had a 4.0 Ranger before with 4.10's and the engine was screaming on the highway, which is why I got a Trac with 3.73's.

 

[chad551]

It may also have the Trac-Loc rear end as well. When I bought mine the 4.10 gearing included the Limited Slip.

Chad

 

[flya727]

Thanks for the great intel. I do agree that a larger tire will bring down the ratio and i will have to adjust the speedometer for the change.

Chad, how do I tell if my truck has the limited slip axle? The only way I knew I had the 4.10 is that I crawled under the back and read the tab on the differential. Would I have to take my VIN to a dealer to find out what they put on this truck?

Thanks,

Rick

 

[chad551]

I know the dealer can decode your VIN for you, but you can also do it yourself online. I am almost positive though it has the Trac-Loc (Limited Slip)in it, since you have 4.10 gearing.

Chad

 

[JohnnyO]

http://www.therangerstation.com/tech_library/Axles.html

 

[briwayjones]

Chad, how do I tell if my truck has the limited slip axle? The only way I knew I had the 4.10 is that I crawled under the back and read the tab on the differential. Would I have to take my VIN to a dealer to find out what they put on this truck?

Look on the sticker on the door jamb. There is an axle code. There is a list on this site somewhere that tells you what the code means.