99 Expedition Stuck in A4WD
#1
99 Expedition Stuck in A4WD
Hello,
Not trying to beat a dead horse because this topic has been covered in various other forums on the internet but I need a few specifics because I am moving in a couple weeks and the drive is 900+ miles.
I'll spare you all of the pre-breakage details. Here's where I am at currently:
Truck is stuck in 4WD via the A4WD function. If I flip the selector to 4H I hear the faint 4H-click in the transfer case and the 4x4 light comes on. If I shift to 4L I hear the big transfer case clunk for 4L (in neutral of course). I can sift from A4WD to 4H to 4L all day long without a miss. However when I shift back to A4WD the truck remains in 4WD (without the dash light because it doesn't come on when A4WD is engaged).
How do I know it's in 4WD? I'm glad you asked. I have ridden in and driven this vehicle for 18-years. I know every creek, crack, cigarette burn and stain. Also, when I make sharp turns the truck binds and pretty much ceases to move until I straighten the wheels a bit.
Troubleshooting performed thus far.
-Checked fuse 104 under the hood, it's good.
-Checked all the fuses in the cab, all good there.
-Pulled fuse 104, truck still remains in 4WD.
-Unplugged shift motor after putting fuse back in, still stuck.
-Jacked the truck up with all 4-wheels off the ground hoping to try to prove or disprove the issue. With the shift motor unplugged the 4WD remained engaged (all wheels would spin - granted it's limited slip so I would have to stop the front passenger's tire in order to make the front driver's tire spin).
-I have tapped the shift motor with a big-*** screw driver, not sure what I thought that would do but when you're out of options beating on things feels good.
-Changed both CV axles hoping one of them was engaged. I did that first and it should have went at the top of the list.
-Ball joint are good (I know that wouldn't matter here because I have ridden on bad ball joints for a very long time and that didn't affect 4WD).
-(Bought a used GEM on eBay) - swapped it today. Pretty sure the damn thing came out of a vehicle with manual windows because my power windows no longer function.
-Checked front differential fluid and transfer case fluid - I think the transfer case may have been a little low on transmission fluid. I pulled the Output Shaft sensor which is magnetic and it had a very very minimal amount of shavings on it so if the gears are ground it's not showing there.
*I changed the shift motor 1.25 years ago (just adding that in here).
I am sure I've done more here but I am mentally exhausted, life has me down.
My questions are these:
-Is the shift motor a possibility? It shifts to 4H and 4L, could it prevent shifting back to 2WD?
-Transfer case shot? Shifts into 4H and 4L...you know this by now. I don't drive this truck fast and I am hardly rough on it (minus duck season, that's when it sees 90% of its yearly driving).
-Any suggestions?
Thanks for the help in advance.
Not trying to beat a dead horse because this topic has been covered in various other forums on the internet but I need a few specifics because I am moving in a couple weeks and the drive is 900+ miles.
I'll spare you all of the pre-breakage details. Here's where I am at currently:
Truck is stuck in 4WD via the A4WD function. If I flip the selector to 4H I hear the faint 4H-click in the transfer case and the 4x4 light comes on. If I shift to 4L I hear the big transfer case clunk for 4L (in neutral of course). I can sift from A4WD to 4H to 4L all day long without a miss. However when I shift back to A4WD the truck remains in 4WD (without the dash light because it doesn't come on when A4WD is engaged).
How do I know it's in 4WD? I'm glad you asked. I have ridden in and driven this vehicle for 18-years. I know every creek, crack, cigarette burn and stain. Also, when I make sharp turns the truck binds and pretty much ceases to move until I straighten the wheels a bit.
Troubleshooting performed thus far.
-Checked fuse 104 under the hood, it's good.
-Checked all the fuses in the cab, all good there.
-Pulled fuse 104, truck still remains in 4WD.
-Unplugged shift motor after putting fuse back in, still stuck.
-Jacked the truck up with all 4-wheels off the ground hoping to try to prove or disprove the issue. With the shift motor unplugged the 4WD remained engaged (all wheels would spin - granted it's limited slip so I would have to stop the front passenger's tire in order to make the front driver's tire spin).
-I have tapped the shift motor with a big-*** screw driver, not sure what I thought that would do but when you're out of options beating on things feels good.
-Changed both CV axles hoping one of them was engaged. I did that first and it should have went at the top of the list.
-Ball joint are good (I know that wouldn't matter here because I have ridden on bad ball joints for a very long time and that didn't affect 4WD).
-(Bought a used GEM on eBay) - swapped it today. Pretty sure the damn thing came out of a vehicle with manual windows because my power windows no longer function.
-Checked front differential fluid and transfer case fluid - I think the transfer case may have been a little low on transmission fluid. I pulled the Output Shaft sensor which is magnetic and it had a very very minimal amount of shavings on it so if the gears are ground it's not showing there.
*I changed the shift motor 1.25 years ago (just adding that in here).
I am sure I've done more here but I am mentally exhausted, life has me down.
My questions are these:
-Is the shift motor a possibility? It shifts to 4H and 4L, could it prevent shifting back to 2WD?
-Transfer case shot? Shifts into 4H and 4L...you know this by now. I don't drive this truck fast and I am hardly rough on it (minus duck season, that's when it sees 90% of its yearly driving).
-Any suggestions?
Thanks for the help in advance.
#2
The switch between A4WD and 4H is electrical not mechanical. The shift motor only shifts between 4H and 4L. Since pulling fuse 104 does not release the front clutch then that means there is internal breakage/damage to the transfer case. If you want to wait to fix it until after you move you can remove the front driveshaft and the truck will drive like a 2WD one.
#4
Pulled the front drive shaft. Definitely a good bandaid for this issue. Truck drives normally again. For anyone removing their drive shaft in the future. Need a 12mm 12point socket, a 2" and 12" extension and a decent length half inch ratchet. 3/8 short ratchet doesn't have nearly the leverage. Doable with a short 3/8 ratchet but not optimal.
Thank again alloro.
Thank again alloro.
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Sean_Memphis
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
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03-08-2015 03:17 PM