I was towing a 10k 5th wheel up a mountain and took a wrong turn! Hey, it was a short cut! Turned out tp be a winding 12+%grade that took me down to 2nd & 1st gear. Of course the engine pulled it fine, but for the first time ever the stock tranny temp warning light came on. It was right at the top of the mountain with no pull off so I kept going and kept the revs up a little as we leveled off and sloped down. We were 0ne mile from desination so I don't think it got much hotter than when the light came on.

questions;

does the warning come on at 250? or 260? on a 2002 47re

does the light go off after below 225?

where is the sensor for the warning light located?

the fluid is still reddish and I can't tell if it smells burt or not, maybe?

The fluid did not come out of the tranny but I could smell fluid

I had just changed the fluid with atf4 and the filter 1000 miles ago, also added a drain plug.

we will not be towing again for a few months so what should I do?

By the way I have a 250 degree max electric gauge on the out line. I was seeing 200 to 220 in town stop and go traffic for short periods but running 175 in OD down the highway. Climbed the interstate I40 mountain into Ashville NC in 3rd and peaked at 230, no light, 8 or 9% grade I think. Gauge was at 250 when warning light came on.

Thanks for any help

 

Don't have my service manual handy...but I believe the light comes on at 285*. With brand new fluid and a short duration event, you will be ok. Light should either go off when you drop down in temp....or after shutdown, on restart.
Is your 220* in town while towing or empty... sounds high. And the 175* on the Hwy....if empty...that's a bit high?? On a warm day in clear air at 75 mph... I use to see 150*-160* with stock tranny.

Temps over 225* will deplete ATF additives much more quickly. If you tow a lot at high temps, I would change fluid @ 10,000 miles....cheap insurance. Was this the first fluid change since new??

Keep rpm's up, like you said, in the mountains is essential, IMO. I would not let it get above 225* for any length of time and you should be OK.

RJ

 

Are you using the tow haul button? You don't want the tranny slipping with that kind of weight.

 

ROWJ; those temps were all while towing, temps when not towing are in the 150 to 160 range and not over ~190 in heavy traffic, if that high.

Is there a way to test the fluid???

There is no towhaul mod on an 2002!

ANY OTHER THOUGHTS OUT THERE!!!

 

I've had my tranny temp guage pegged at 280+ for 15-20 minutes on a steep windy road and the stock temp light never came on,
sensor is in the hot line.
As soon as I got to the top and leveled out, the temp dropped to the normal 180 or so pretty quickly.

The fluid was a bit brown, and smelled of burnt bread, the next time I changed it.


phox

 

My 02 Service Manual says the light comes on when receiving a signal from the PCM that the fluid is at 275* or higher and will go off when temps drop below that level...or the key is turned off..... whichever comes first!
Simple test for ATF is to wipe the dip stick off with your fingers. Good red color and no burnt smell tells you your ok. Still may need to change more often if temps get over 200* regularly.

RJ