Blinking 4wd Lights

[vrey10]

I have an '02 explorer and i'm having a problem with the 4wd. when i turn the truck on the "4wdhigh" and "4wdlow" lights flash 3 times and the 4wd doesn't work. I did some research and thought maybe it was the speed sensors on the transfer case, so i changed them both and that seemed to work for about a week. Now the problem is back and i don't know what to do from here.
I would appreciate any feedback Thanx

 

[SkanlaxJMO]

Have you reset the computer?

 

[vrey10]

I pulled off the battery terminal and waited a few minutes. That seemed to solve the problem for a day or so.But then it would come right back.

 

[nlancasters]

computers are touchy

you have a problem with some part of the drivetrain that the computer monitors. You're thinking "DUH!".
have you checked your tire circumfrence? As little as 1/4 inch difference can throw the computer off.
. my best advise is to take it to a ford dealer and have them diag. it. it might cost you $60 - $100 but how much did your sp.sen.s cost.
if the shop tells you that it is something mechanical within the transfer case its probably the shift shaft(i can't remember the proper term). its purpose is to manually engage the 4x4 & switch between 4h &4L. The auto function is done by a magnetic ball ramp clutch. the shift shaft is motor driven (i think you can see this actuator on the outside of the t-case) if you take the motor off and fiddle with the shaft (it has a triangular male shaft about 3/8in) you might be able to feel that something isnt right(such as deflection at the oppisite/internal end). the piviot mount on the other end of this shaft is very small and I have seen them break.
if you are not an experianced mechanic the repair of this could be dificult.
I can get onr out in 35min on a lift with a jack. in a driveway with limited hand tools this could take several hours or days depending on skills and resources. then taking apart the t-case is tricky too, but not as bad as putting it back together.

hope this helps
nlancasters@hotmail.com