Trans temperature gauge

[poncho62]

OK, heres the deal...I installed an Autometer tranny temp gauge in my truck this morning...4L60 trans....Its about 35-40 degrees around here, winters coming...Went into town to run a few errands. Temp on gauge went to about 125F, that was about it. Ran a total of about 10 miles. Is this normal for this time of year?..How long should it take to get up to operating temp this time of year, or is this the normal temp for this time of year?

Just trying to get a baseline here, as I have never monitored trans temp before.

[CKNSLS]

DougE wrote:
If you search some you will find most sources state that the design operating temperature of automatic transmissions is 175*. You will also find that most life vs. temperature charts for auto transmissions do not go below 175*. This is the reason behind installing an auxiliary cooler prior to the radiator cooler. This allows cool trans fluid to be warmed up to the correct temp as the outlet of the engine radiator is ~175*.

Yea, there is a trans temperarture chart floating around the internet that's been wrong for ten years. There is no "normal" as long as it stays within the temoerature range where the fluid is designed to work. See my post above.

[DougE]

If you search some you will find most sources state that the design operating temperature of automatic transmissions is 175*. You will also find that most life vs. temperature charts for auto transmissions do not go below 175*. This is the reason behind installing an auxiliary cooler prior to the radiator cooler. This allows cool trans fluid to be warmed up to the correct temp as the outlet of the engine radiator is ~175*.

[Me_Again]

I have a temperature probe in both the output line and the tranny pan. The temperature in the pan normally hardly warms up at all as wittmeba noted above.

The temperature at the output line reacts quickly to things like stop and go traffic, and spotting a trailer in a park site. I am convinced that you will burn your tranny down completely before a temp probe in the pan alerts you to over heating.

When my output temperature starts climbing past 235 it is time start changing or stopping what I am doing.

My tranny is custom built for towing with a tight torque converter, so in stop and go traffic I place it in neutral. It valve body has been modified to circulate fluid while in neutral. Towing on the highway with the torque converter locked I see 170 or so at the output line.

I wonder about all the people that have no way to monitor this and do not know the conditions they can easily subject their tranny to.

Chris

[wittmeba]

Transmission fluid doesn't heat heat up much unless you drive your truck pretty hard.

Transmissions like 4R100 only heat the fluid while slipping. Transmissions only slip when shifting and 1, 2 & 3 gear. 4th gear the transmission will lock not allowing any slip.

When I installed my Trans Temp Gauge I thought it wasn't working as it never seemed to move. It values started at about 100º and normal driving didn't move it much.

[CKNSLS]

The hammer is right. As along as it's in the parameters of the fluid you should be OK.

[Chuck_thehammer]

there is NO temperature thermostat for the transmission.

if you have the sensor near the radiator output it will read lower.. (cooler)
if you have the sensor near the transmission output side.. will read higher.

you need to learn how the temperature that is normal for your TV. with and without loads.

going up hills ...temp will rise..
going down hills. .. temp will lower.

[CKNSLS]

The Dexron 6 has been tested up to 285 degrees-

In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

“General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. "

[Mvander]

Sounds about right. It will get warmer in the summer. My 4l60 will hit 190 towing in the summer.

[n7bsn]

Never used a 4L series, but the temp sound reasonable. You want them warm, and that is not unusually so. I would expect the transmission to get warm in 4 or 5 miles

[mguay]

On the average...ALL of my GM's have run about 100deg above the outside temp.