Originally Posted by Cape Fear
I know that only the LII axle specified 75W140 so that tag can be used to ID the axle but what part of the
4L10 88 3E15
tag IDs it as a LII axle. The only thing I can read out of that is 8.8 axle 4.10 gears & Limited slip
I can't decipher it either. I was just posting it for comparison to anything that might be found on the 03 FX4 Off-Road axle.
It's not likely that you would find a LII axle on a non-LII by mistake. Ford usualy builds specific packages in batches to cut down on misbuilds and increase efficiency.
Here's an easy check that can be done without referring to axle tags or markings. Go out and measure the diameter of the axle tube near the u-bolts. A 31-spline Level II axle is about 3 1/4" and a 28-spline is something like 3".
If you don't have a caliper or micrometer handy to measure the diameter, wrap a string around and mark the circumference. Then transfer the string measurement to a tape or rule.
A 31-spline should be about 10 1/4"
A 28-spline should be about 9 1/4" ~ 9 1/2"