Overdrive OFF light flashing question
 

Hi all, haven't been on this forum for a while.... actually found a JOB!! after 5 months. Part of the job involves towing a trailer with a pretty large load. I just completed a 12 hour trip from Hailey, Idaho to Sand Point, Idaho pulling a 26 foot trailer with a full load of cabinets. I was real careful to turn off overdrive over the two mountain passes and had no problems during the trip. The last leg of the trip was an extreme uphill from Sand Point to the Schwietzer ski area, real slow, many hair pins, burned about a 1/4 tank of fuel in 1/2 hour. Even though I turned the overdrive on the shift lever to "OFF" it started to blink. What does this mean, should I do something to prevent this? This long hauling is not something I'll have to do a lot so would prefer to not spend much on some expensive mod. Thanks in advance!

Welcome back Brad...i have no help other than to say you should've got a palm shaker...lol

Anything else going on with the dash? Speedometer working OK?

A flashing OD light usually means there is a tranny code set. Have the codes read. If there are any be sure to post them.
Be sure to clear any codes that may be set so you see if they come back if you get another flashing OD light.

It may be a code set due to overheatig that once cleared may not come back. If you are going to be doing any more heavy towing flush and fill the tranny if it has been awhile. I know you don't want to spend money on mods but a tranny temp gauge and auxillary tranny cooler could save you there cost from preventing any overheating.

Congrats on finding work. :-drink

Brian eveything else is ok Robin sorry- sitting on top of a mountain so no way to read codes. After we unloaded for about an hour it stopped flashing, so it's probably ok but I'm concerned about what to do on future hauls. Don't want to be stranded out in the middle of BFE with no tranny.Thanks for the replies.

I added to my previous post. Reread.

Also check your ATF. Does it smell burnt or is it discolored, very dark?

Thanks Robin, I'll check that and look into a temp gauge. I'm running Shaeffers ATFand had it changed about a year ago, had the screen dropped and cleaned and I believe I had a filter changed at that time.

I would also suggest you replace the 203 stat for a 195 or even a 192. Little things make a big difference when towing heavy AND uphill. Hopefully you won't have any problems going back down the mountain. At least you'll be able to keep up to speed and get some air flow through the rad and atf cooler. Did you hear the fan kicking in for long periods? The fan cluch locks up at about 220° under hood temp.

EGT gauge also suggested.

The number one killer of transmissions is heat.

Thanks Robin,
The fan didn't seem to be kicking in any more than normal (had a Chev 350 that did that a lot) Really just wondererd what the flashing OFF light meant. It's pretty cold around here so i doubt the engine temp got that high, but not sure. Thanks for the input, just drove 12 hours and unloaded for an hour so am going to sign off Talk to you soon

Hope your trip down the mountain is/was uneventful.

Definitely a driveline code, mine flashed when speed sensor was going out, code reader read the problem and cleared code. All fine after replace speed sensor. Definitely scan for codes.

There are also a couple pressure sensors ive heard in the trans. Ive heard they can get gummed up and need to be pulled, cleaned and replaced. They have been known to throw a driveline code. Mine does it when its below freezing occasionally.

There are no pressure sensors in the transmission.

Get the codes read. They will stay in memory for about a month after the last time the light flashed. It could prevent a trans meltdown.

Thanks for the knowledge, its just what i was told a long while back. I cant remember the code mine throws but its the same everytime it does it. Its something like "high pressure input" etc. cant remember. Does that ring any bells?

Mark,
I'd like to get the codes read before I get on the road, heading south tomorrow.
Anyone know where I can get codes read between Sand Point Idaho and Hailey Idaho without paying a $85 charge at a stealership?