View Full Version : gear ratio?

zim bob the landscaper
06-04-2007, 03:44 PM
how do you find the gear ratio on a truck btw its a 89 ford f250 and i want to swap out the axle for a dually 1 ton axle but dont knoe the gear ratio thanks alot!

06-04-2007, 05:51 PM
couple of ways find the tag on the rear end housing (if its still there) or you can pull the cover and it will be stamped on the ring or count the teeth on the ring and divide that by the number of teeth on the pinion.

zim bob the landscaper
06-04-2007, 05:54 PM
there is a small medal tag with a bunch of numbers but not the ratio do i do something with those numbers

i think it says on it L70 10 29D20

06-04-2007, 06:18 PM
you have half the tag, there is two lines to the axle tag. The first thing it will say is 3L55, 3 55, 4L10, 4 10, 3L73, 3 73. The "L" is limited slip and without it the diff is open

06-04-2007, 06:19 PM
There may be a code in the glove box.....don't know what the ford code would be though

zim bob the landscaper
06-04-2007, 07:43 PM
heres a pic of the sticker inside the door not great but ok

zim bob the landscaper
06-04-2007, 07:44 PM
if you could tell me the code that would be awsome

AWJ Services
06-04-2007, 09:10 PM
The bolt on the tag on the rear end usually will cover the first part of axle ratio.

Take the vin and take it too the dealer an dthey can tell you.

06-05-2007, 06:48 AM
if that sticker says "B5" as the axle code, then its a 4.10 limited slip
if its a 35 axle code then its a 4.10 open