i want better acceleration for my 2003 3.0 liter, 5 speed ranger. i was thinking about differentials. what should i upgrade it to, or will this do hardly anything? will this positively influence my fuel economy? how much would this cost to get done? thanks.

 

i dont know much about rear ends but new ring and pinions alone cost a lot. for someone to install them would be a lot too. maybe a differential w/ different gears from a salvage yard that would bolt right up would be a good idea.

 

Well, to get increased seat of the pants feel and acceleration will require you to go with a numberically higher gear. As an example, replace 3.55's with 3.73. However, this will drop your gas mileage since the engine is reving higher.

 

Look at the sticker on the door post for the differential code and look it up. There is a list of codes in the tech section at the top of the fourm (Its marked READ ME in red). The lower gear (higher number) will give you better power and acceleration but will reduce you gas mileage. If you have a 4 weel drive you will need to change both front and back and it can be expensive maybe $1500.00 or more.
Dave

 

If you're going to swap gears, don't swap from say, a 3.55:1 to 3.73:1. The difference will hardly be worth the money. Go to a 4.10:1 if it is available in a 7.5" differential. You very well might want to move up to an 8.8 rear end if you get serious about this, there are far more rear end ratios available.

Don't forget to swap out your speedometer gear as well!

 

Go to a lower(numerically higher) ratio. If you have 4X4, it's probably not worth the expense to convert front and rear. On a 4X4, the front and rear must always be the same, unless you are really good with math and can calculate a tire size that will compensate for the gear difference.
If it's 4X2, go to the local salvage yard, and find a Ranger with a numerically higher ratio than yours, pull it out and plop it in yours. A B-Series will also bolt in. I have heard you have to move the shock mounts and spring perches if you get a rear axle out of an Explorer, Mountaineer, or Aerostar.
If you get an 8.8 from a 4.0 Ranger, make sure you get the mounting plates from it too, I believe the 7.5 is different in that area. Otherwise, the 8.8 should be a direct swap.
You could go out and buy a ring and pinion set for your current 7.5. Richmond Gear has several, even up to 4.56:1, and they run about $160. The only problem is getting them installed. You have to know what you are doing to install it correctly. If you install it wrong, you risk premature failure and a loud howling noise until then. Professional installation is a must, and that cost money.
Fuel Economy will decrease most likely, unless you have to floor the gas pedal all the time now to achieve proper acceration, and with the new gears you can stay out of it more. Good Luck.

 

I have re-geard two of my rangers now, I went from 3.73's to 4.10's, one in my 93' 4x the other in my 99' lifted 2x. The older one it worked out fine, but in the 99' the computer had problems....my gas milage was awful after the gear swap. Look into it, see if you can get the dealer to re-program the computer for this. I was at that point, ended up trading in for a newer 4x instead -