My O/D lamp lights and the transmission comes out of overdrive while
driving at highway speeds (typically 60-70 mph). This behavior just
began today, I am not towing and the ambient temperature is around 50
degrees. One time the Transmission Hot indicator came on, but went out
after I stopped, turned off the engine and restarted.
If I stop and turn off the engine, then restart, the O/D indicator goes
out and the transmission works fine for probably 15-20 miles, then the
routine starts over.
The transmission has plenty of fluid, still red, but I do smell that
telltale hot "something" smell when I walk past the radiator.
I have never changed the transmission fluid/filter. Should I have the
dealer change it and adjust the bands as the owner manual says?
Any other ideas?
The transmission will drop down to 3rd gear if the fluid gets too hot - I
suspect that's what's happening to your truck. Or, at least, it _THINKS_
the fluid is getting too hot. Yes, I would get the fluid/filter changed
(should have been doing this every 24K), and have them check for a plugged
cooler. With a proper scan tool, you can read what the computer thinks the
transmission fluid temperature is, and read the actual temperature via an
infrared thermometer on the cooler supply line. If the two readings are
vastly different, the temp. sensor (part of the governor pressure sensor) is
probably bad, and would need to be changed.
First have the fluid completely changed, not just whats in the pan.
Make sure the pan is dropped and filter changed. Since you have a 2001
I'm assuming the fluid is way past it's intended life and the filter is
possibly clogged. That would cause things to heat up. Hopefully no
damage has occurred.
I change my fluid once a year or every 20K. I do tow sometimes though.
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