What is the 2018 ford f150 axle code l9?

The code l9 is associated with a 3.55 electronic locking differential on the 2018 Ford F-150. But why is Your diff lock so important The diff lock forces all wheels to spin at the same speed, regardless of traction. This is helpful if You encounter difficult terrain and one or more wheels leave the ground, as full power remains on the other wheels ensuring You are still moving in the direction of travel. A typical rear differential repair costs anywhere between $200 and $400. These typical repairs would include Your bearing, seals, and fluid changes. Of course, when a gear change is required, that's when things get pricey. $1,500 is just the MINImum You can expect to pay for new gears.