axle codes

[rusty7072]

i have a 2001 ranger but i have put a different rear end in it i bought this rear end out of a junk yard i dont know what kind of truck it is out of and there is no tag and i am trying to replace the driver side axle the only number i could find is on the end of the hub and it is 878aa if any one could give me some insite it world be greatly appreciated i think it is a 7.5 rear end and the axle is 28 spline and in think it has 4.10 gears not sure though

 

[metalmacguyver]

Take a picture of the diff cover and we can tell you. You can also pull the cover and measure as best you can the diameter of the ring gear.

 

[Ranger44]

That suck the tag is missing. I'd agree with Metalmacguyver. Try to post a pic.

You can count the teeth on the ring and pinion to determine the gear ratio.

This a 4x4?