StreetCreeper
Active Member
I had been experiencing some some issues with grinding on the drivers side wheel in the morning when it’s colder. After some quick research, I realized the 4wd system on my 2003 Expedition is vacuum controlled and mine was malfunctioning.
Essentially I was losing vacuum and the drivers side actuator was releasing into the hub...or trying to. This causes the grinding as the actuator is trying to actually actuate (couldn’t resist sorry) from loss of vacuum since Ford designed the system to require vacuum for normal 2wd operation and no-vacuum for AWD and 4wd operation.
So if the vacuum is lost from a leak or other failure, the actuator(s) will try to engage under spring pressure and disengage as your vacuum pressure rises and falls across the actuator vacuum pressure threshold that is required to keep them open. I think I read somewhere it was about 5-7
This intermittent actuation has probably caused some damage to the actuator gear itself I suspect. Luckily I just threw it into AWD once I suspected it was related to the 4wd system. Switching to AWD left both actuators engaged but still allowed for normal street driving. So hopefully not enough damage occurred in those few occurrences to worry about, plus no more intermittent god awful grinding with the intermittent vac loss which was friggin embarrassing as hell the other morning as I was dropping my kids off at school and of course right in front of the school with everyone and their freakin uncles all standing around when it suddenly sounds like I just ran over some poor kids tricycle and am dragging it down the road leaving gouge marks & leaping sparks along my path.
Luckily my kids are too young to be embarrassed ... but man, I most definitely lost some “cool dad” points somewhere if even only in my own book for that little stunt... ( pulls ballcap down low and shrinks into seat...)
So this morning I tested most things in the system and found no leaks. Both actuators held vac as did all the lines and reservoir box.
I went and pulled a used IWE solenoid from the junk yard and installed it. So far I haven’t had any problems with it but I only spent about 20 minutes driving around in 2wd again. We’ll see if it does it grinds in the morning again when it’s colder though.
While I was underneath fiddling with the actuators I happened to shine my light up and noticed the radiator support was a big rusty pile of flakes. I didn’t fiddle with it – lest it turn into red dust before my eyes, but it looks like I could run a screwdriver up in there pretty good. The other side isn’t as bad as the driver, but it’s got issues too.
I have no experience with rust, but this truck belonged to my folks who live on the coast in the Pacific Northwest. So that’s where the rust came from. I’ll be researching more on this issue in the coming days, but what’s the general forum consensus on repair for this? Can any rust-pros out there tell me how bad this rust looks? I’m going to run a camera up there tomorrow and get a better look, but to my untrained eye – that crap don’t look good.
Finishing out my day with the Expy, I wired in a dashcam so I can record all the dipshits on the road. Had to hack up the fuse-box cover for the fuse tap since it stuck out the side a good bit and so precluded the cover from closing fully. Yeah I butchered it and it looks like crap – but it works. I ran the wires from the camera through the headliner to the pillar and then ran it down the pillar into the dash and hardwired it to the fuse box with that tap. Not professional by any means I’m sure, but an automotive electrical engineer I am not!
Oh I also pulled an electric mirror switch from the junkyard this morning since mine seemingly doesn’t work on its own but I know my mirrors will move ( jerkily though ) because the memory presets have them moving between my wife’s settling and mine. I was too lazy to take the door panel off today though. Perhaps tomorrow I’ll swap out the mirror switch and see what happens.
Overall a fairly productive day.
Essentially I was losing vacuum and the drivers side actuator was releasing into the hub...or trying to. This causes the grinding as the actuator is trying to actually actuate (couldn’t resist sorry) from loss of vacuum since Ford designed the system to require vacuum for normal 2wd operation and no-vacuum for AWD and 4wd operation.
So if the vacuum is lost from a leak or other failure, the actuator(s) will try to engage under spring pressure and disengage as your vacuum pressure rises and falls across the actuator vacuum pressure threshold that is required to keep them open. I think I read somewhere it was about 5-7
This intermittent actuation has probably caused some damage to the actuator gear itself I suspect. Luckily I just threw it into AWD once I suspected it was related to the 4wd system. Switching to AWD left both actuators engaged but still allowed for normal street driving. So hopefully not enough damage occurred in those few occurrences to worry about, plus no more intermittent god awful grinding with the intermittent vac loss which was friggin embarrassing as hell the other morning as I was dropping my kids off at school and of course right in front of the school with everyone and their freakin uncles all standing around when it suddenly sounds like I just ran over some poor kids tricycle and am dragging it down the road leaving gouge marks & leaping sparks along my path.
Luckily my kids are too young to be embarrassed ... but man, I most definitely lost some “cool dad” points somewhere if even only in my own book for that little stunt... ( pulls ballcap down low and shrinks into seat...)
So this morning I tested most things in the system and found no leaks. Both actuators held vac as did all the lines and reservoir box.
I went and pulled a used IWE solenoid from the junk yard and installed it. So far I haven’t had any problems with it but I only spent about 20 minutes driving around in 2wd again. We’ll see if it does it grinds in the morning again when it’s colder though.
While I was underneath fiddling with the actuators I happened to shine my light up and noticed the radiator support was a big rusty pile of flakes. I didn’t fiddle with it – lest it turn into red dust before my eyes, but it looks like I could run a screwdriver up in there pretty good. The other side isn’t as bad as the driver, but it’s got issues too.
I have no experience with rust, but this truck belonged to my folks who live on the coast in the Pacific Northwest. So that’s where the rust came from. I’ll be researching more on this issue in the coming days, but what’s the general forum consensus on repair for this? Can any rust-pros out there tell me how bad this rust looks? I’m going to run a camera up there tomorrow and get a better look, but to my untrained eye – that crap don’t look good.
Finishing out my day with the Expy, I wired in a dashcam so I can record all the dipshits on the road. Had to hack up the fuse-box cover for the fuse tap since it stuck out the side a good bit and so precluded the cover from closing fully. Yeah I butchered it and it looks like crap – but it works. I ran the wires from the camera through the headliner to the pillar and then ran it down the pillar into the dash and hardwired it to the fuse box with that tap. Not professional by any means I’m sure, but an automotive electrical engineer I am not!
Oh I also pulled an electric mirror switch from the junkyard this morning since mine seemingly doesn’t work on its own but I know my mirrors will move ( jerkily though ) because the memory presets have them moving between my wife’s settling and mine. I was too lazy to take the door panel off today though. Perhaps tomorrow I’ll swap out the mirror switch and see what happens.
Overall a fairly productive day.
