This morning I hooked up my fifth wheel camper to take it to storage. About 5mins from my house. Went up one steep hill maybe 4 blocks long. No problems
Dropped off trailer. After that tranny started to shift oddly. Long shifts, to short shifts. Then after twenty mins maybe it started to overheat.finally set the overheat light and flashing tow/haul light. Not far from house babied it home.
Checked for leaks. Only one I could find is from the top of the tranny towards the back maybe from the overflow? Checked fluid none on stick at first. Then after it sat for abit it had some on it all the way up to the hot line. It's Sunday and there is only one place that carries the sp tranny fluid and there closed today. So I m stuck till tomorrow . Any ideas? Could it be a clogged cooler or is the tranny cooked. Please help I really don't want drop $5000 grand on new trans. Thanks again for help Kelly

 

When was the tranny fluid and external filter last changed and what fluid was used? You also need a ScanGauge ll min. to read the actual temps. The stock gauge is a stepper switch type idiot light with a needle hooked to it.

 

You need to check the Trans Fluid WHILE Running in Park Hot

Sounds like the Trans fluid is WAY WAY Low

 

Check your coolant for transmission fluid and do NOT drive it until you get it figured out. I would think that your transmission cooler ruptured if it got that hot, that quickly! If so, you will be flushing that cooling system with Simple Green until it's all out. Check it first, I'm not saying that is what happened, but.... well...

 

Or the TFT sensor failed.

 

These trans don't have to many issues that require a complete rebuild

I had a Bad TFT sensor it would go into limp mode shift all jacked up ect....

And Bad TFT Sensors are pretty common

I could watch my TFT as I Drove the first couple miles it would Jump all Over from say 70*f to over 8000*f so very very drastic temp swings and NO WAY it was 8k F in a mile LOL

I would get the correct amount of fluid in there then check TFT @ cold soak against ECT and EOT after cold soak All Fluid temps should report same or very close to same after 12 hours cold soak sit

then watch as it heats up for tft to Jump around it should rise steady in temp

 

If it was the TFT sensor, he wouldn't have had transmission fluid come out of the fill tube right? It actually did overheat and the fluid came out. To me, that means it wasn't the sensor.

 

Yes I assume it overheated because there is Very Little fluid in it

 

Checked fluid seems to be right up there. But after sitting for six hours tranny temp came
right up to half on the gauge. only for running for ten min. Sorry I don't have a scan tool readily available so I can't tell you exact temp. Trans fuild looks very light pink on a white
dipstick. So do I service the trans. Risk doing that and the tranny still cooked or do the coolers go bad? Doesn't look like any trans fuild in the coolant. I maybe went five miles
with the gauge pegged and the tow haul light flashing.

 

If you want the truth, you NEED a scangauge II or similar to monitor the temp when it is completely cool (after 10 hours sitting). Monitor the temp when it is completely cold and it should be almost IDENTICAL to the Engine Oil Temp (EOT on Scan gauge) and Engine Coolant Temp (fWT on scangauge). If you are in a rush, they have the scan gauge II at Autozone for $160. I wouldn't drive one of these trucks without live gauges. There are other options, but you need gauges!

If you change out the fluid, that will run you $5.99 a quart and you will need 18 quarts. You can only drain 8 qts at a time, so when I did mine, I drained 8 quarts, refilled, drove it 200 miles and drained 8 quarts and refilled and then did it one last time. 24 qts total for maintenance because you aren't technically getting a clean 18 quarts with a drain and fill.

18 quarts alone is about $115 after tax. If you have a ruptured tranny cooler, then you've wasted all your money and will have to do it again.

For what it's worth, you are braver than I am. I would have shut my truck off and checked the transmission temp and had it towed. You're playing with fire if you don't have something to read live data. If you have an Infrared thermometer, you can check the pan temp too. Report that back for the experts.

 

I don't see where he stated that he had fluid coming out of the fill tube.

 

There is on the back of most trannies a vent tube and that's where I think it came from. Sorry about the confusion.

 

so how did you check the Fluid??

 

I checked fluid with the dipstick. But it looked thin. Thanks for the price on the tranny fluid that helps out a lot. But how much does the TFT sensor cost, is the tranny cooler cooled by the trucks coolant or on the front of the radiator. Like I said there was no actual fluid pouring on the ground, frame, or lines. So has to be internal right? Is it the TFT that went bad yes it would be easier with a scan tool .calling john wood tomorrow to see what he thinks to. Just asking everyone. Is the lv mercon safe to run in these trans?
Thanks for all the replies and tips you guys are great

 

But are you checking the Fluid with the Truck @ IDLE in Park HOT

I believe it specifies this on the dipstick


That's how it should be Done

So If its showing Nothing while Idling in park on the dipstick its going to Seize the Trans


Mercon LV is Fine

It came with mercon SP so that's what I stick with until I cant find it anymore