So my 1997 F-350 Crew cab Dually with 209,000 miles start flashing the overdrive off light at me last month....

It has been sitting parked as I am also having cold start (glow plug relay) issues and do a lot of short hop driving.

I took it to a couple of mechanics and they say it is throwing a p1728 code.
Which I realize is a torque convert slip issue.

Well last Saturdays I decided to try and fire it up and top off the tanks as it was un seasoable warm.... I left it plugged in for 2 hours came back and it fired right and magically no more flashing OD off light....

Is it common for the OD off light to quit flashing like that? The only other thing I did was put the winter front on it....

 

If in fact there is a TC issue the light will return..

 

I would replace the tc now before it sends shrapnel into the rest of the transmission.

Richard

 

I was wondering if maybe the cold (read thicker) fluid was causing a small issue to become a bigger issue and set the light off...

I plan on running it over to the mechanics this weekend to get the GPR fixed (prob 100 miles round trip)... and then its off to get the tranny rebuilt...180 miles to that shop...

 

It isn't unusual for the light to not come on again. The PCM has to detect the converter slipping, and it can only do this in fourth gear with the converter locked.

Cold fluid will make this LESS likely to happen. The problem with those converters is that the apply piston develops a crack and leaks pressure. This reduces the pressure holding the clutch applied, and it slips. Thicker fluid won't leak as much pressure as thin fluid.

 

My light was orginially coming on with it parked just after start up.....

I had done nothing to clear the code.... What your saying seems oposite of what is happening?

 

The light will reset every time you turn off the key. It won't come on again until the PCM detects whatever it is seeing that is wrong.