Axle Codes Simplified (?)
The axle code found on the VC Label inside the drivers side door jamb of '92-'96 F-Series and Broncos is relatively easy to decipher (this may apply to older trucks as well, but I don't know for certain).
Each digit means something.
The first digit in the axle code tells you if it's Limited Slip (Posi) or not, and it's (the rear end's) weight capacity. Deciphering the weight capacity code is too complex to explain, but whether or not it's Limited Slip is easy. If the first digit of the axle code is a letter, it's Limited Slip. If it's a number, it's a one-legger. The actual letter or number specifies the rear end weight capacity.
The second digit tells you the gear ratio.
All that have a second digit that is a:
8 have 3.08 gears,
7 have 3.31 gears,
9 have 3.55 gears,
5 have 4.10 gears.
For example, all axle codes that start with a letter, and are followed by a 9 have a Posi 3.55 rear end, while all axle codes that start with a number, and are followed by a 9 have a one-legger 3.55 rear end.
The only exception I am aware of is the code W5, which is a 4.00:1 one-legger rear end with an 8250 lbs. capacity.
Other one-legger rear ends include axle code:
12 which has 2.73 gears and is rated at 3800 lbs.,
72 which has 4.63 gears and is rated at 11,000 lbs.,
73 which has 5.13 gears and is rated at 11,000 lbs.
4x4's that have a Limited Slip front axle will have a third digit in the axle code, usually a "2".
So, H92 would mean it was a 4x4 with 3.55 gears, and that both axles were Limited Slip.
FWIW, all Ford truck/van axle codes follow the first digit rule (letter = posi, number = non-posi) EXCEPT for the previously mentioned F-Series/Bronco axle code W5, and the Aerostar axle code 22 (4.10 posi).
I hope this helps with any junkyard trips or simple curiosity. I tried to make it as simple as I could. It's really not tough, once you get the hang of it.