USMC64-70

Last year I installed the ATS torq converter and valve body and a double deep fluid pan. The deep pan holds about 1 gallon more fluid than stock. Since that time my fluid temp stays in the 125 to 150 degree range, even while towing.

I know heat is the main destroyer of transmissions but am wondering if it is harmful to run with fluid that never gets to 175 or 180 degrees? My trans runs great but just curious.

kd460

Have to ask, where is your temp sensor?? True you want to get the temp up there to help remove any moisture, but if your temp sensor is in the pan, then your temps are good.
Kevin

MCummings

[quote author=USMC64-70 link=board=16;threadid=21876;start=0#msg204645 date=1067806146]
125 to 150 degree range, even while towing.
[/quote]

Running it too cold won't hurt it.

But, You should remember the old saying,,
"If it sounds to good to be true........"

Check that Temperature sender placement.

Merrick Cummings Jr

USMC64-70

My temp sensor is in the Mag Hytech pan. I guess the sensor could be faulty but has only been installed for a year. Sounds like fluid temp is not a problem unless it gets real hot.

Thanks

pappyman

The tranny temp sensor should be where the fluid is the hottest which would be the out line to the cooler...if the sensor is in the pan its not a true reading since its reading temps from hot fluid mixed with fluid thats been cooled...I think normal tranny fuild temps at the out line run 150-170*

kd460

I agree with pappyman, but the pan temp can give a guideline. Since your sender is in the pan, then your temps are right in line with others who have a sender in the pan.

The pan is not a good measure of temp, only a guideline (for reasons pappyman stated). You really don't want to know what the temp of the fluid is after it is cooled. You do want to know what the temp is before it is cooled. The hottest it's gonna be is as it exits the out line (or the to the cooler line) from the torque converter. Thats your true measure of temp.


I just found this little bit of information doing a search on google under "transmission temperature chart" Hope it helps, Kevin

"Automatic transmission fluid will provide 100,000 miles of service before oxidation occurs under normal operating temperatures of about 170°F. Above normal operating temperatures, the oxidation rate doubles (useful life of fluid is cut in half) with each 20° increase in temperature.
The approximate life expectancy at various temperatures is as follows:

175°F 100,000 miles
195°F 50,000 miles
212°F 25,000 miles
235°F 12,000 miles
255°F 6,250 miles
275°F 3,000 miles
295°F 1,500 miles
315°F 750 miles
335°F 325 miles
355°F 160 miles
375°F 80 miles
390°F 40 miles
415°F Less than 30 minutes

This information clearly shows why transmission oil coolers and the various maintenance intervals are recommended for severe usage.

Above 300°F, the metals inside the transmission will warp and distort in varying degrees depending on the severity of overheat. Because this damage occurs and fluid life is so seriously impaired, rocking out of snow, mud or sand should never exceed a very few minutes."

BTW, I did read that to cool of a fluid is not a good thing either.

MCummings

Hey, well darn, I still have 300 more miles to go since last night.

Watch those trans temps,, if you aren't moving and you are working your truck hard, the Cummins has no respect fluid coupling, and will melt down any trans when pushed hard enough.

Merrick Cummings Jr

kd460

Yes!, case in point, parking my 5'er in the woods. Took about 20 minutes listening to my wife give me the wrong instructions , and that temp climbed to the hottest that it has ever been, 238 degrees. While not bad, it was a little warmer than I liked.

The factory trans cooler really needs air flowing through it. It really heats up during stop and go, especially if your only cycling from first to second and then back down again. Luckily, popping it into neutral and increasing the engine revs to say about 1500 rpms, will do a decent job of bringing it back down.

I think the trans cooler could have been put in a better spot (like more centered on the radiator) to have better air flow during slow or stop and go travel. Problem is clearance of the grill and the latch mechanism. Then you also have to worry about over cooling if you live in colder climates, but I think I would rather have that problem then under cooling.

I guess to sum it up, a trans temp gauge is just as important as an EGT gauge, and having accurate readings is critical.
Changing tranny fluid on a regular basis is just as important as changing the engine oil. Know what temps start to break down the fluid, and if you ever run into problems, check them out ASAP, before major damage ($$) is done. Kevin

tmiller24

The cooler on the front of the radiator, in my opinion, is a waste. By the time the fluid goes thru the water jacketed exchanger on the right side of the engine and all the lines, there can't be too much heat left. I'm really surprised a bean counter didn't kill it.

Edward

USMC64-70

I also have the double deep pan with the temp sender located in the back of it. My ATS setup runs about the same temps as what you are seeing. The ATS is an efficient design that does not produce excess heat. At those temps you should get years of dependable service.

Edward