My O/D (overdrive) light has started flashing for several miles at a
time and then stops. I'm usually at a slower speed when it occurs and
can't really tell if I'm losing my high gear when this happens. Any ideas?
The OD light actually serves 2 functions. It indicates OD being locked out (by
driver pressing the switch), and also functions as as a malfunction indicator
for the transmission.
If it is flashing there is an electronic concern with the trans, but not
just with OD. The electronics can also pick up certain mechanical problems.
There will be a Txxxx fault code set, which is retrieved via the OBD II port
like Pxxxx codes for the Check Engine light. The proper scan tool can also read
data when the concern happens to help with diagnosis..
The Ford Dealer is your best bet for non-generic OBD II issues like this, but
local independent or transmission shop should have the proper scanner (and
to help diagnose the problem. The key word here is "good. There are many fine
shops and transmission shops that can help you if you want to avoid the dealer.
can be hard to find, though. "Word of mouth" is their best advertisement, so ask
around and find out who other folks trust in your area.
Even though you don't sense (hear, feel, smell) a problem when the light is
flashing, you need to get it checked out right away. It could be simple and not
of a problem, but it could also signal an expensive repair if left unattended.
Good Luck, and let us know what you find out.
Tom - Thanks for your reply. I took the truck to a transmission shop.
They had the scan tool hooked up when the O/D light was flashing and
the code set was: P0741 - Torque Converter Clutch Performance or Stuck
Off. They told me that probably means the Torque Converter has gone bad
and usually it sends material into the transmission that ruins that too.
The next step in the diagnosis is to remove the pan and see what kind
of contaminants are in the transmission oil. From that they say they
can determine how extensive a repair is necessary but probably I'm going
to need a new torque converter and a rebuilt transmission $2-3000. The
vehicle is only worth $5000 at the most but is in great shape other than
this. Does their diagnosis seem reasonable to you? The truck runs fine
but I do lose the O/D gear when the light is flashing. I appreciate
your comments. Dave
Tom Adkins wrote:
I think $3000.00 is a bit steep for a new or remaned transmission. You
should be able to pick up a re-manned trans for about 1500.00, they are
pretty common transmissions.
As for crap going into the rest of the trans, I would just make sure they
flush the cooler real good (back flush it) and flush the whole tranny, and
put a new TC and filter in, and your trans should be good to go..
I doubt you would need a new trans for a TC problem, the fluid flows from
the TC to the cooler and back to the pan to be sucked up by the pump. So the
filter should stop any debris that doesnt get caught in the cooler.
OOhhh, hard call.. (98 Explorer 4x4 Auto trans rebuilt for $3000). Ford Tech
correct in saying that you can "buy" a reman for $1500. You have to then have it
installed, which is no small feat on an Explorer. Usually about $1000. You have
find someone willing to install your $1500 trans with some liability.
If the converter spit debris into the trans, it's often done for due to the
contamination. You could pay someone to replace just the converter for ~$1000 in
that it will solve the problem. It might. It might not.
As you can see, $3000 is about what you will have to spend if the trans has
compromised, one way or the other.
Once again thanks for helping me with this issue. The transmission shop
told me that they would need to pull the transmission along with
the T/C and with that done they would go through the transmission to see
what needs replacing (if anything). Most likely there would be some
problems and I would end up with a rebuilt transmission (they do the
rebuilding) as well as a torque converter. No sense they say to pull
the transmission and not take a look at it to see what might be wrong.
Their estimate is $2100 - $2600. Another shop that I trust estimated
$2000-$2200 for the same thing. The truck is in great shape, it's paid
for, and I could probably get several more years out of it so I'm
inclined to go for it. If I wait a while do I stand to do more damage
to the drive train and end up with a higher bill at a later date? Or
worse yet, get stuck somewhere? As I've said the truck runs fine even
with the O/D light flashing occasionally. Is there any likelihood that
that light is an erroneous indication and the code set is sensor
malfunction? The shop says no. Dave
Tom Adkins wrote:
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