I have a 2000, F250 V10. At 60mph in overdrive it is turning 2200 rpm. And I'm running 265 75 16 tires. My tag on Rear end is gone so I can't look there. I just would like to know what ratio my gears are? Thanks, Youall are the best.

 

there should be a sticker on teh door jam of your truck..

it will have a code that you can post and someone here will decipher it for you..

it will be something like 37LS or similar. which in the above case would indicate a 3:73 limited slip.

 

if you're turning 2200 (or there about) in OD with the torque converter locked as well, you're looking at about a 4.88 gear.

 

Using a RPM calculator if you where totally lock up you would be turning 2072 rpm but if you are using the Ford tachometer and any slippage in the converter I would guess that you have 3.73 gears. If you had 4.30 you would be turning around 2388 RPM in OD. I used 31.6 tire diameter.

Denny

 

i have to say false. i'm running 265/75/16 with 4.30 gear in my Excursion and at 60 mph i'm right at 2000rpm's WITH the converter locked up.

 

My bad I used .87 instead on .7 for the OD gear. You have 4.3 gears

Denny

 

just don't make it a habit, lol........ it's all good, can't give a fellow cornhusker to much trouble, lol!

 

It was just CRS I guess I've been looking at the new gearing in the new 6 speed to long.

Denny

 

i hear ya, to many things to keep in line what goes with what, lol!

 

What calcuator are you using? I'm using this one and the numbers are very different but your numbers are closer to what I am ACTUALLY getting.

4R100 4.30 285/75/16 65mph=~2400rpm

Engine RPM Calculator

 

I used RPM Calculator but like I stated I used the wrong final OD gear and at 60 mph not 65 mph. Using your calulator and your tires 32.8" 65 mph I come with 2863 out of OD and 2004 in OD. I would check and see if your trucks computer was updated for the larger tires and if your tachometer is right.

Denny


After doing some playing if you have 3.73 gears and are out of OD you would be turning 2484 rpm and 1739 in OD at 65 mph.

 

Odd. According to the calculator, I am running 4.88 rear end gear...... Something is off. I guess that is what makes not being the original owner really suck.

 

Using your calculator and 285/75/16 (32.8") tires, 4.88 gears, 65mph, .7 final tranny gear ratio (OD) I come up with 2275 rpm and if you are using the factory tachometer that's close. One way to check and see if your speedometer is right because of the bigger tires is to get a GPS and check it going down the road.

I also used your calculator and tried it with 265/75/16 (31.6) a stock size tire and came up with 2361 rpm. So I would say that your computer has never been re calibrated for the larger tires.

Denny

 

Here's 4.30:1 gears in an Excursion with stock 265/75/16 size tires:

 

Scott, That's close to where I am running, only I'm indicated to be slightly higher with my 285/75/16.

Denny, I definitely need to jack up my truck and count my driveshaft revolutions to figure out if I REALLY have 4.30 like the tag says or if a past owner swapped in 4.88 gears. Then pull out my GPS to check speed. THEN I need to figure out if my tach is correct.