Auto transmission temperatures

Finally got my scangauge upgraded, which by the way is free if you walk it into their office here in phoenix, and can finally get transmission temperatures. I thought I'd post what I've observed so far.

Stock 2007 4runner, V6, with Duratrac 265/70-17 (1 inch larger dia).

Today was the second day of use and during my commute into work with temperatures around 90, the transmission stays around 170 deg on the freeway. If I hit stop and go traffic it'll go as high as 190 and if I stop for more than 10 seconds it'll go to 195-200.

When I started the engine at the end of the day, the tranny temp was still 124. For my commute back home, ambient was about 115 with the dash thermometer saying 117. The hottest it got from an on ramp run was 216 deg and it didn't want to get below 200 for the rest of the commute.

I'd be really interested to see how hot it gets while towing my popup trailer to the mountains.

Does it have the towing package from the factory?
(you can tell by looking at your fan clutch should be pink in color)

Those temps sound about right, when having to change the fluid in these its not fun and we have to watch the temps to do it right, usually when I first bring in Runner, Taco, or FJ they are right around the 190 range and usually takes all day (summer time) to cool it down.

IF your worried about the temps getting to high, look into upgrading the fan clutch to help you pull more air through.

Holy heck. I thought it was hot here.

The fan clutch is pink and I have a factory hitch and 5 pin (or is that 7 pin?) trailer wiring.

Working in the garage is not an option for me right now. Way too hot. It's funny, by the end of summer, you forget how cold it can get in arizona. By the end of winter, you forget how hot it can get in arizona.

I'm at 60k so it's time to do a flush when it cools off later in the year. I figure I'll install a tranny cooler then.

Update:

I towed our popup camper up to the mountains over the weekend and got some more data.

The peak temperature I saw was 236 deg f and that was on some long hauls up moderately steep hills, however not the steepest hills. The steepest hills required a downshift and with the engine turning higher revs, the transmission temp went down. I think this is where it's in a lower gear but the torque converter is locked.

On what seemed like flats but were probably very slight uphills, the transmission would stay firmly over 200 deg, mostly around 215 deg.

Whenever it got lower, like going downhills, it stayed right around the same temperature as the coolant temp, which was around 185 or so.

Ambient temperatures were anywhere from high 90s to the 70s.

I really wish the scan gauge would data log long trips.

Quote:

---

Originally Posted by Robinhood4x4

Update:

I towed our popup camper up to the mountains over the weekend and got some more data.

The peak temperature I saw was 236 deg f and that was on some long hauls up moderately steep hills, however not the steepest hills. The steepest hills required a downshift and with the engine turning higher revs, the transmission temp went down. I think this is where it's in a lower gear but the torque converter is locked.

On what seemed like flats but were probably very slight uphills, the transmission would stay firmly over 200 deg, mostly around 215 deg.

Whenever it got lower, like going downhills, it stayed right around the same temperature as the coolant temp, which was around 185 or so.

Ambient temperatures were anywhere from high 90s to the 70s.

I really wish the scan gauge would data log long trips.

---

At 215, did you get any warning lights? I was off-roading up some steep grades and working the tranny hard. Lots of rocks and dirt, spinning tires. I actually got A/T Temp light to come on. Didn't have my scan tool with me so I have no idea how hot it got, but I'm sure it was pretty high! Just wondering at what point the light turns on. I did turn off the engine for a short time and it went away. Never saw the light come on again, afterwards (thank goodness!).

No, the light has never come on, even at 236 F.

FYI, next time it comes on, put the tranny in park and keep the engine running so the fluid gets circulated through the radiator.

Quote:

---

Originally Posted by Robinhood4x4

No, the light has never come on, even at 136 F.

FYI, next time it comes on, put the tranny in park and keep the engine running so the fluid gets circulated through the radiator.

---

That's the stupidest thing I've ever heard! LOL... no seriously, that sounds like a good idea. I'll do that next time, but hopefully, it'll never do it again! Hahaha. Kinda freaked me out just a little because I didn't even know there was a LIGHT for that! Hahaha.

not sure how comparable it is, but the temperature red line on the tranny temp gauge on my parents' Chevy 2500 is at 275F. I would assume it should be close since it is the fluid's temperature range, rather than the transmission itself.