driving around town the light stays off, but if im on the highway for a while the light will turn on. my 8.8 3.55 LS clutches are going to hell. my question is can the transmission sense the clutches going bad? because this light only turned on after i changed an axle seal and realized that half of my clutches were gone in my diff because i was turning it all around trying to figure out where these metal tabs came from in my fluid.

 

OD light flashing means you have a transmission fault

 

why would it come up only after messing around with my diff.?

 

could be as simple as even having bumped the wire to the speed sensor loose

 

Get your codes read with a scanner than can read Ford transmission codes.

 

Dumped my Expy cause of that darn light, our tranny shop could never figure out what it was...traded it in.

 

you should have dumped your tranny shop...not the truck.....

 

In my town that shop was the best, they have been around for 30 years. It was them, an Ammco and some other franchise, the kicker was I had an extended warranty that expired 1000K miles before the light began flashing.

It turned out ok, cause if I still had it I would not have my current ride (which is 2 rides later than the expy shown below).

Back then I hung out on Ford Truck World...

 

what year truck and 4x4 or not?

my 97 had an issue with the speedo drive gear (plastic) swelling up and spinning off the shaft.

 

97 4x4 4.6

 

mine started blinking on sunday so it is in the shop today will let you know what my problem was

 

same config as mine, you may have the same issue i had especially if theres no symptoms and the trans acts fine. i never got a straight answer on why the speedo drive gear swells, but it happened to me several times until i put some epoxy on the shaft and the drive gear.

 

wont have an answer till friday they called and told me to take it to the tans shop here in town to get it fixed

 

how could i tell if its happening?

 

if its just the speedo drive gear you'll eventually lose your speedo.

be best if you could get a code.