450i not engaging into 4x4

[glengust]

Ok now that’s it’s warmed up my 450 is still not engaging into 4wheel drive.  I thought it was related to the cold. I’m getting power to the actuator cause I can hear it trying to function. I seen there is 3 bolts that fasten it to the differential but it look the top one was impossible to get at. Any thoughts

[airshot]

     Just looked at my service manual, they say the front diff assembly needs to be removed before the actuator (2wd/4wd) can be removed. There is a shift rod inside that is operated by an electric motor. Have you changed the diff oil and cleaned that out first?  A good cleaning is easy when compared to removing the front diff.  I would give the diff a thorough cleaning than if it doesn't work, grab a service manual and take the diff actuator apart. For some reason I am still thinking the actuator may be sticking, thus the thorough cleaning of the front diff.  Have you tried the diff lock mode?  Does that work?

[glengust]

Lock didn’t work as well. I’ll try cleaning out the diff. Thanks for the insights. I’ll keep posted on my findings. Won’t get to it till this weekend.

[glengust]

 The only problem I seen with removing that actuator was the top bolt, the other two were accessible but the top one was hidden behind some piping. Thought about just loosening up the differential to see if I can get out the top bolt at all without taking it so far apart. Look like I need to take the wheels off and obviously get the shafts out in order to get the differential out. Along with changing fluid and cleaning the differential I’d like to see what that actuator is actually doing or not doing as well. My wife and I like to go up in the mountains and I don’t need any trouble when I’m 40 miles away from nowhere. Thanks again

[glengust]

The actuator seems to be functioning. I took it off and with it plugged in turned the switch and watched the miter shift arm moving back and forth. Before I go into the differential is there anything I might be missing??

[airshot]

     My service manual does not give a "troubleshooting" area for the diff assembly only a disassembly and reassembly instructions. It does mention a test for the actuator but you already said it works. I have the online version and a hard copy of the service manual from "Cyclepedia",  they do offer some trouble shooting services if you join. It is only around 50 + bucks for a lifetime membership. I have not had any issues but they have been helpful on questions I have had.