I tackled this job today and figured I'd add pictures of my actuator for more data points.
First off, thanks Teckis and others for documenting this. Especially
@isthatalexus for his post way back in 2022 outlining the clocking procedure.. that's what I used and it went great.
My rig has 240k, a lot of which is highway, very little corrosion, very consistent maintenance. I would rarely get a flashing CDL light, but cooler weather and especially cold mornings when camping in the mountains would help trigger them. After things were warmed up a power cycle would generally clear it. For that reason it wasn't very high on my priority list. I would also get an error code related to the 4wd system stored in the computer, but I can't remember what it was.
Lately I started to get a couple flashing lights in the middle of a texas summer.. that's a sign I needed to handle this. Then I couldn't get it to clear after the first warm up cycle, and when exercising the actuators a few miles from home in a parking lot I almost got it stuck in 4Lo. That prompted me to read all the way through this thread.
In my case, there was zero corrosion inside the actuator housing or motors, or the microswitch. Literally the only spots that didn't look perfect were the spots that the contactors spent most of their time on the rub strips. Switch ohmed out perfectly, and looked great inside.
Breather hose was cracked, substantially.
I just cleaned off the impacted areas of the rub strips and contactors, spread the existing grease around, put the switch back together, and bolted it all up with a new silicon hose and we're back in business.
A note about the hose.. the rubber portion is only a few inches long, attaching to a smaller diameter poly line that runs along the top of the Tcase and transmission. You can easily work the old rubber line off and replace it with 3mm silicon vacuum hose. That stuff should be far more resistant to the temps under here and outlast the truck.
Pics for data
actuator end
poly line end. Note what appears to be some glue
