Help finding for the 4.10 gear ratios I do not want buy a new rear axle

 

You need to know which size rear differential you have first, 7.5" or 8.8" Rangers had both

Look on drivers door label and get AXLE code, read here: https://www.therangerstation.com/tec...le_codes.shtml

That will tell you the size of the Ring and Pinion set you need

Then google: Ford 8.8" 4.10 ring and pinion set

OR 7.5" instead of 8.8"

You also will have the option of Limited Slip(posi-traction) or OPEN type for either size

There is a setup procedure for changing ring and pinion gears, they need to be "shimmed" correctly or will burn out/up, so you have to assemble and dissemble it a few times to get it "just right", which is why people often swap out the whole axle, its just easier
The setup is a bit of an art, but there are many videos and how-tos on this procedure

Google: ford 8.8 ring and pinion swap

OR 7.5"

 

You can buy just the ring and pinion online. Just keep in mind it requires special tools to install them properly and professional installation is recommended.