95 t-case wont shift in 4wd on fly

[95FordExpXLT]

Today, I tried to shift into 4wd and the switch illumination backlight went out as soon as the switch went to 4wd, and the dash lights started flashing (6 times) and had no 4wd. Later in the day, I checked all the fuses and re-seated them and everything appeared OK. Now it will shift into 4wd as tested in the garage, I could hear the shifting into both 4hi & 4lo, shifting from neutral back into gear. Taking for a test drive, it would not go into 4hi unless at a complete stop and moving back & forth from neutral to drive.
It will shift out of 4hi back to 2wd while driving, but not into 4wd. 4lo appears to work as is supposed to, only going in and out in neutral.

 

[slravene]

thats how it is supposed to work.....you dont shift into 4low while driving.

 

[SkanlaxJMO]

the flashing 6-times is the battery re-set problem...on your switch do you have 2wd-4-auto-4-lo?
iff so the 4auto is not really 4hi.
As for the 4-lo "problem" thats the way it is supposed to work.

 

[daves97sport]

clarification on problems

The 4LO is OK- not a problem. It is the 4HI that should be able to shift on the fly, but will not engage unless stopped and shifted into neutral.
I believe the switch is 2WD,4HI,4LO but not sure-it's my Son's vehicle that we were trying to figure out last night and can't get ahold of him now... Anyway, with the slick roads we had last night, it was a good testing grounds - the 4WD - HI or AUTO - was not engaging when it was supposed to.

 

[gijoecam]

The 4LO is OK- not a problem. It is the 4HI that should be able to shift on the fly, but will not engage unless stopped and shifted into neutral.
I believe the switch is 2WD,4HI,4LO but not sure-it's my Son's vehicle that we were trying to figure out last night and can't get ahold of him now... Anyway, with the slick roads we had last night, it was a good testing grounds - the 4WD - HI or AUTO - was not engaging when it was supposed to.

If it's a 95 or 96, it'll be 2wd, 4auto, and 4 low. They didn't introduce the 4auto/4high/4low setup until the 97 model year (when they did away with the Center-Axle Disconnect on the front axle).

If it was flashing a code, it's honestly easier to have the dealer run the codes and pin-point the problem. If I was a bettin' man, I would guess that when it attempted to shift into 4 auto (which essentially just locks the front axle and automatically engages the t-case as needed) it didn;t see the front driveshaft speed synch with the rear shaft speed and figured there was a problem with the system. If it locks into 4 low (and actually drives all four tires in 4 low), that tells me that the transfer case clutch coil is working. That would lead me to believe that it's not seeing the front and rear driveshaft speeds as being the same unless you're stopped.

Now, once you engage 4 auto at a stop, when you start moving again, does it continue to work, or does it kick out again?

-Joe

edit: If anyone can find the lamo fault codes for the control trac, I'd appreciate it. I couldn;t find them for the 96 model year....
J