Just a couple months ago, me and my dad were up north with my dad's 2000 expedition (5.4). We were going up a muddy hill and the truck's automatic 4-wheel drive kicked in because the back tires were spinning. Ever since then, the front end made loud popping sounds when we turned corners on and off road. I got advice from someone on this board (can't remeber who) to drive it four wheel for awhile, since the truck had not been in four wheel much. After we did that the noise went away, but we went up north again and the automatic four wheel came on again and the problem is back. We tried driving it four wheel for awhile and then took it out, but it doesn't help any more and the noise is a little louder. Its like the front end is binding up, like when you drive in four wheel on the pavement, but the sounds aren't the same. When we had it in four wheel we turned a tight turn on hard dirt and the normal pops were few and far between, but when its out of four wheel, the pops are more constant and it pops about every second you are turning the wheel. Does anyone know what could be the problem or has anyone else had this problem with the automatic four wheel drive?

 

Anybody have ideas?

 

Man, this could be any number of problems. Here are a few places to start:

4WD mode switch.
Circuitry.
CJB Fuse 23 (10A).
A4WD clutch relay/circuit.
Contact plate sensors A, B, C and D circuits.
Transfer case shift motor/circuit.
Transfer case shift relays.
Transfer case mechanism.
GEM.

My advice would be to take it into the shop rather than try to speculate as to the problem. Looking through my manual, it could literally be one of many hundred things causing your grief.

Good Luck.

 

Thanks for the info Buzzard, my dad is planning on taking the truck in, in the next week or so to find out whats wrong and how much it will cost.

 

Topfisherman
I have a 99 w/A4wd with a similar problem. Did you find out what caused the problem?

 

Well, we took in the truck and the Ford mechanic said that the transfer case was bad and that the truck won't come out of 4 wheel. We decided not to have the transfer case fixed yet because it would be $1500 for a new one and about $300-$400 for install. Just tonight we put the truck up on jackstands and drove it and it would spin the front tires when it wasn't in the 4 wheel position on the switch. As for a temporary fix, we might just take off the front driveshaft just so we don't get the vibrations. greenbeast if you do a search for A4WD, you will find that there are a lot more people with '99-'00 expeditions with the same problem as us. When I did a search, I found that Buzzard had the same problem as us and I was trying to find out if he got the problem fixed at all. If you look at my other post, Help bad transfer case (https://www.ford-trucks.com/forums/s...d.php?t=220840), I found out some more info about problems and temporary fixes.