Identifying Your Axle From The Axle Tag:

You can identify which axle you have by the tag attached to the inspection cover.

Here is an example of an axle tag:

Looking at that tag, you can see the gear ratio stamped on the lower left, and the axle size (ring gear diameter) stamped in the bottom middle.

So looking at the axle tag above, you can see it’s a 3.73 gear ratio in a 7.5 inch axle.

And looking at the axle tag above, you can see it’s a 3.73 gear ratio with a limited slip in a 8.8 inch axle.

Axle Codes (Door Sticker):       

Rear axle codes can be found on the Safety Standard Certification label attached to the left drivers side door lock post.  The code appears as a number or letter/number combination in the ‘Axle’ column of the label. 

If you look at the ‘AXLE’  section on the label above, you’ll see that this Ranger has a ‘F7’ axle code. Using the chart below, we know that this axle is a 7.5-Inch axle with a 4.10 limited slip.

Axle codes for Ranger, Bronco II, Explorer and Aerostar (included because 4.10 gears and limited slips are more common than you’d expect)

Ranger
Code Description  Capacity Ratio
72 open 6-7/8″  2200  3.08
74 open 6-7/8″  2200   3.45
82 open 7.5″  2750  3.08
84  open 7.5″ 2750 3.45
85  open 7.5″  2750  3.55
86 open 7.5″ 2750 3.73
87  open 7.5″  2750 4.10
 89 (1992-1998)  open 7.5″  4.10
 89 (1999-2001)  open 7.5″  4.56
91 open 8.8″  2750   3.27
92  open 8.8″ 2750 3.08
95  open 8.8″  2750  3.55
96 open 8.8″  2750 3.73
97 open 8.8″ 2750 4.10
98 open 8.8″  2750 4.56
F4      L/S  7.5″  2750  3.45
F5 L/S  7.5″  2750  3.55
F6  L/S  7.5″  2750  3.73
F7 L/S  7.5″  2750 4.10
 K6  L/S  8.8″  4.10
R5 L/S  8.8″  2750 3.55
R6  L/S  8.8″  2750 3.73
R7 L/S  8.8″  2750      4.10
R8 L/S  8.8″ 2750 4.56 
(Note 4.56 geared axles ’99-up are 31-spline)
 
Bronco II
Code  Description  Capacity  Ratio
42 open  7.5″ 2640 3.45
44 open  7.5″  2640 3.73
47 open  7.5″  2640 4.10
D2 L/S    7.5″ 2640 3.45
D4 L/S    7.5″ 2640 3.73
D7 L/S    7.5″  2640 4.10

 

Explorer
Code Description Capacity  Ratio
41      Open 8.8″ 3200  3.27
 42  Open 8.8″  3200  4.10
43 Open 8.8″ 3200 3.08
44   Open 8.8″  3200 3.73
45  Open 8.8″ 3200 3.55
 46  Open 8.8″  3200  3.73
D1 L/S   8.8″ 3200 3.27
D2  L/S   8.8″  3200 4.10
D4 L/S   8.8″  3200 3.73
D5 L/S  8.8″  3200  3.55
L73 L/S  8.8″  3200  3.73
L – Limited Slip Differential
C – Conventional Differential

 

Aerostar
Code Description  Capacity Ratio
22  open  7.5″ 2950 4.10
23 open  7.5″ 2950 3.45
24 open  7.5″ 2950 3.73
25 open  8.8″ 2950 3.27
29 open  8.8″ 2950 3.55
B2 L/S    7.5″  2950 4.10
B4  L/S    7.5″  2950 3.73
B5 L/S    8.8″  2950  3.55
B9  L/S    8.8″  2950 3.55
(Note: Aerostars with axle codes starting with “1” are Spicer/Dana 30 axles with Aluminum housings)