how can i find out what my rear axel ratio is?

 

Couple of ways.

First of all, you can get under the truck and look at the differential. There should be a tag held on by one of the bolts.

You can decode using that.

Or you can look at your door sticker and decode it using this:
https://www.ford-trucks.com/article/...r_Decoder.html

Many are available and they changed throughout the years, off the top of my head, 3.08, 3.45, 3.55, 3.73, 4.10, 4.56. I believe the 3.55, 3.73, and 4.10 were available with limited slip.

 

my door tag says R7 for axel which isn't an option on the link you gave. however, following the logical progression of the other options, i would guess that means it's a 4.10.

 

Yeah there are some problems with the decoder on the website.

So I assume you used the tag method and it showed 4 10 with no L in the middle?

 

i didn't get under the truck to look at the axel tag. i looked at just the door tag. my guess about the 4.10 ratio is due to the fact that R5 is 3.55, and R6 is 3.73. It just makes sense for R7 to be 4.10. I know I have a Torsen Limited Slip.

 

R7 being a 4.10 LS seems familiar... but they show "F7" being 4.10 LS.
84 – 3.45 Non-LS
86 – 3.73 Non-LS
87 – 4.10 Non-LS
89 – 4.56 Non-LS
F6 – 3.73 LS
F7 – 4.10 LS
92 – 3.08 Non-LS
R5 – 3.55 LS
91 – 3.27 Non-LS
96 – 3.73 Non-LS
R6 – 3.73 LS

I still suggest you get under the truck when you get the chance, just to confirm.

 

i couldn't find a tag like the one you posted underneath my truck. the only tag i see on the rear axel/differential says V313L over and over again. it's wrapped around the axel on the passenger side.

maybe it would help to say that i have a 2005 Ranger FX4 Lvl 2.

 

The 05 lvl 2 should have a 4.10 torsen diff.

 

Ranger <address style="margin-left: 3px;"> </address> <table border="1" width="100%"> <tbody><tr> <td width="25%"> Code

</td> <td width="25%"> Description

</td> <td width="25%"> Capacity

</td> <td width="25%"> Ratio

</td> </tr> <tr> <td width="25%"> 74

</td> <td width="25%"> open 6-7/8"

</td> <td width="25%"> 2200

</td> <td width="25%"> 3.45

</td> </tr> <tr> <td width="25%"> 82

</td> <td width="25%"> open 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.08

</td> </tr> <tr> <td width="25%"> 84

</td> <td width="25%"> open 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.45

</td> </tr> <tr> <td width="25%"> 86

</td> <td width="25%"> open 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.73

</td> </tr> <tr> <td width="25%"> 87

</td> <td width="25%"> open 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.10

</td> </tr> <tr> <td width="25%"> 91

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.27

</td> </tr> <tr> <td width="25%"> 92

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.08

</td> </tr> <tr> <td width="25%"> 95

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.55

</td> </tr> <tr> <td width="25%"> 96

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.73

</td> </tr> <tr> <td width="25%"> 97

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.10

</td> </tr> <tr> <td width="25%"> 98

</td> <td width="25%"> open 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.56

</td> </tr> <tr> <td width="25%"> F4

</td> <td width="25%"> L/S 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.45

</td> </tr> <tr> <td width="25%"> F6

</td> <td width="25%"> L/S 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.73

</td> </tr> <tr> <td width="25%"> F7

</td> <td width="25%"> L/S 7.5"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.10

</td> </tr> <tr> <td width="25%"> R5

</td> <td width="25%"> L/S 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.55

</td> </tr> <tr> <td width="25%"> R6

</td> <td width="25%"> L/S 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 3.73

</td> </tr> <tr> <td width="25%"> R7

</td> <td width="25%"> L/S 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.10

</td> </tr> <tr> <td width="25%"> R8

</td> <td width="25%"> L/S 8.8"

</td> <td width="25%"> 2750

</td> <td width="25%"> 4.56

</td> </tr> </tbody> </table>

 

Got the chart off of TRS. I'm not an active member over there, but they do however have a VERY extensive tech page.

 

what's TRS?

 

(sorry guys I'm not trying to promote a different site here!)

http://www.therangerstation.com/

Check out the tech library. Alot of good info in there.

 

Something has to be up with that chart, the FX4 - 2 definetly comes with the 8.8" axle and the 31 spline gear with a 4.10 ratio unless custom ordered. The chart is incorrect, in that it specs the "F7" code as a 7.5" axle, which it is not.

 

my truck says R7 on the door, so F7 may be correct on the chart.

 

you can roll the truck and count the number of turns to the rear wheel. mark the drive shaft, mark the tire, let it roll and count the number of ds revolutions to the 1 tire revolution (360deg). Will give the approximate ratio and you can fine tune from there.