Transmission got a little warm today.

[meep]

Interesting thought: with older transmissions that we wanted to keep 160-180 max, it required both the radiator loop and an auxiliary cooler. the internal loop alone might do that under most conditions until the radiator temp creeps up over 160+, in which case the auxiliary cooler was required. conversely, if the transmission starts at 200 and ideally needs to stay under 210F, that same coolant loop ends up being far more useful over most of the operating range.

I know the 10r80 I’ve got, even worked hard with a travel trailer on some of the steepest climbs I had it on, without the HD package, without an extra cooler, was extremely well-controlled. I don’t think I saw it ever go over 220 and it cooled rapidly as soon as the terrain changed. and of course, the AC was running too.

 

[nascarnation]

Never saw any correlation between what ATF is used & Transmission Sump Temperatures. You guys ought to see what Converter Charge Outlet Temperatures get up to

I've run my Allison 1000 up to 240° several times over 400,000 miles without the use of boutique ATF, Mostly Mobil Delvac 1.

I consider 100° above ambient to be normal......240° spikes are acceptable when work20 ing the unit hard.

FWIW 20+ yrs ago when we did our durability testing at Allison on the 1000/2000 series we ran at 250F sump temp continuously with Dex III which at the time was sourced from Petro Canada.

 

[Chris142]

I set the cluster to show actual trans temp instead of just the dummy gauge all day today. Here is where it runs on flat ground about 60 mph.

 

[cptbarkey]

Just echoing my own mis-understanding of modern ATF fluid temps, I thought I would benefit from adding a more beefy aluminum radiator but for some reason Toyota designs their transmissions to run hot all the time. I also invested in an Ultra Gauge before this mis-understanding. This was this morning's readings going about 65mph, but later it went up to 220 with a slight lead foot taking off from intersections.

 

[CheezWhiz]

all it takes is one little mistake with a hot tranny and it can turn your life upside down ...

 

[ctechbob]

all it takes is one little mistake with a hot tranny and it can turn your life upside down ...

Meaning?

These newer vehicles will go into a reduced power mode if things get too far out of whack. They will protect themselves from someone doing dumb things with them (for the most part, running high temps on 20 year old fluid is not the vehicles fault).

 

[The Critic]

Meaning?

These newer vehicles will go into a reduced power mode if things get too far out of whack. They will protect themselves from someone doing dumb things with them (for the most part, running high temps on 20 year old fluid is not the vehicles fault).

He was implying other things.

 

[ctechbob]

He was implying other things.

Lol, gawd I'm slow today. I really shouldn't reply when I first get up before I'm caffeinated.

 

[CKN]

Had to do a repair up in the mountains today. Took the F550 service truck. I was always told to keep an automatic transmission below 200F and that above 200F transmissions won't last very long. I do not beat on the truck.

I'm actually trying to get it's average mpg up. I guess ford knows more than I do about transmission temps.

It stayed this hot and even hit 230 for a moment.no bells or whistles came on and the trans temp gauge stayed in the middle range. It took a good 20 minutes to cool back down to 200-205 on flat ground.

The reality is no bells or whistles came on because it can take the warmer temps . Somebody is misinformed.