today I started my truck up and let it idle for 10 or 15 mins while I was loading it up, when I got inside the gauge for the tranny temp read just shy of 200*. that seems really high after not driving the truck for 8 hours. then I drove it for about 1.5 hours and it read about 190 195* the whole time. does that seem high for not even driving?

seems high to me, my trans rarely gets that hot even towing.

seems high to me, my trans rarely gets that hot even towing.
X2 - you better check your fluid, check level and see if is turning dark or smells funny like burnt

Yea that seems a bit hot. Check your fluid and maybe do a service.

Fluid level may be too high if you are getting that hot sitting still idling. What was ambient air temp at the time??

X2 on comments above. Do both cold and hot fluid checks. I would spin off your external filter and make sure it is not blocked up or burnt smelling as well.

Well I changed the spin on filter about 2000 miles ago, like 2 weeks I think? I only checked the fluid when it was hot and it read right in the middle of the hot hash marks. it was about 110* outside while idling about 4pm.
today while driving home from work unloaded on the freeway it got to about 210* it was about 110-113* outside. would being that warm outside cause the tranny to run that hot?
the fluid was red and didnt smell burned.

Mine was running at 190 deg today in city trafic at 114 deg in phoenix today.

Well I changed the spin on filter about 2000 miles ago, like 2 weeks I think? I only checked the fluid when it was hot and it read right in the middle of the hot hash marks. it was about 110* outside while idling about 4pm.
today while driving home from work unloaded on the freeway it got to about 210* it was about 110-113* outside. would being that warm outside cause the tranny to run that hot?
the fluid was red and didnt smell burned.
Hight ambient temperatures would definitely affect your tranny temps. In another thread on a similar issue, one member stated there is an old rule of thumb "outside temp plus 100*F". I had never heard this and was intrigued and skeptical. However, for about a month now I have watched my tranny temps during different times of day and temperatures and at least for my truck, that rule has held pretty much ture +/- 5 degress or so. I am not surprised at all that you are that hot when the outside air temp is over 100*F. The pavement is much hotter than that and radiates right up against your tranny body. Keep an eye on it, but knowing now what the air temps were, I wouldn't be too concerned with it.

How hot should I let it get before I back off and let it cool before the tranny gets damaged? Im wondering what it will get up to while towing if it was at 210* unloaded

with that kind of heat you guys in Arizona are getting man it makes Florida cool! Holy smoke you might want to consider a deep pan and maybe a big tranny cooler up front. What kind of temp will you get with a load? :eek:

I have not seen mine above 220.

Mine was running at 190 deg today in city trafic at 114 deg in phoenix today.
ya friday was hot!

with that kind of heat you guys in Arizona are getting man it makes Florida cool! Holy smoke you might want to consider a deep pan and maybe a big tranny cooler up front. What kind of temp will you get with a load? :eek: I know tell me about it...:lol:

Deep pan and earls cooler has dropped me about 30* i run ~150-165*

Mine will get 190 to 195 in 95 degree weather no load just driving around the farm! And while pulling my 30 ft travel trailer and atv trailer in the same outside temps it will get to 210 to 215 and GM told me it was normal! Normal or not I think cooler is better so i will be adding a trans cooler when i get time.

I thought these trucks already had a transmission cooler as part of the HD trailerig package? Is that a misguided thought??

They do have one already but as with most OEM parts they can be improved upon. If you want to keep your trany nice and cool, get a aluminum deep pan and a Mike L trany cooler.
Just do a search for it and you will find a bunch of info on Mike’s cooler.

I thought these trucks already had a transmission cooler as part of the HD trailerig package? Is that a misguided thought??
they do, its just really small.. i bought diff one from jegs i think for 185 bucks not 450...

The allison use to have the pto drive ring installed, GM dropped it to save ~$20 per truck. If you want to run a pto toy, you are looking at a total rebuild to replace the tone ring, with the pto ring. (or a SC5).
For $20 more at the plant GM could have done alot. So now we remove, and toss the tranny cooler, and spend 10 times that, to get a better cooler.

I am not trying to be a smart A$$, but the trans temperature gauge is on the left and the engine temperature is on the right! The only reason I bring this up is someone in the past got confused and read them wrong!:D

It is hard to believe that the transmission temperature came up so fast.:)

I am not trying to be a smart A$$, but the trans temperature gauge is on the left and the engine temperature is on the right! The only reason I bring this up is someone in the past got confused and read them wrong!:D

It is hard to believe that the transmission temperature came up so fast.:)

yep I know what gauges are what:) and yeah it was really hot outside and the trans temp just idling was about 200 and driving down the freeway was around 210.
Ive been wanting to change to transynd for a while now so im getting me a deep pan and bigger trans cooler soon. I wont be towing anything for about a month to see what the temps would be towing in the hot weather because all my toys are broken:(

Make sure your clutch fan is working properly.

Paul, I live in Ventura also and my trans was running the same temps, Also when I go to Arizona and its 100 to 120deg outside my trans temps are that high. I plan on getting a bigger pan and cooler, not because it needs it, just because it will make my feel better when towing.

Paul, I live in Ventura also and my trans was running the same temps, Also when I go to Arizona and its 100 to 120deg outside my trans temps are that high. I plan on getting a bigger pan and cooler, not because it needs it, just because it will make my feel better when towing.
100 deg at 8am and 120 deg at 5 pm :D

I was in Havasu this last weekend, driving around town and it was around the 120 range outside. My tranny temp was around the 200 mark, even driving steady down the highway. I did find out, however, that the dealer had filled it a good quart too much. I dumped enough to get it to just about full (still a little high) and it dropped about 5*.

I just had a service done on the tranny and now it is running hot. It use to run around 150 but now it is running at 200 just driving around on the highway or in town. Before i would tow my fifth wheel and it would reach 200 every now and then.I check the fluid after driving it for awhile and it showed that it is a little low. I am just wondering if they used the wrong ATF or if the filter might be pluged. Anyone have any ideals.

I just had a service done on the tranny and now it is running hot. It use to run around 150 but now it is running at 200 just driving around on the highway or in town. Before i would tow my fifth wheel and it would reach 200 every now and then.I check the fluid after driving it for awhile and it showed that it is a little low. I am just wondering if they used the wrong ATF or if the filter might be pluged. Anyone have any ideals.

You are overfull. Drain some out.

I do not know very much about trannys so i dont want to mess it up or anthing. About how much should i drain out and what would be the best way to drain it out. I was going to take the filter off and dump it out or should i just open the plug and let it drain that way. With it being overfull do you think my tranny is hurt at all it has not been drove that much my wife has had it while i have been at work. Thanks for the help.

I just had a service done on the tranny and now it is running hot. It use to run around 150 but now it is running at 200 just driving around on the highway or in town. Before i would tow my fifth wheel and it would reach 200 every now and then.I check the fluid after driving it for awhile and it showed that it is a little low. I am just wondering if they used the wrong ATF or if the filter might be pluged. Anyone have any ideals.

I am in your same boat, I just had a service done and my tranny is running hotter than usual. I have a ATS stage 3.

You'll probably need to take between a pint and a quart out.

Put the level in the bottom half of the "HOT" band when the trans temp is at 175F.

In my experience being at the top of the HOT grid puts you 2 qts overfull depending on the pan your running.

I took out about 2cups or 1 pint of fluid out of the tranny. With the temp at 150 it shows the level at the top of the cold mark. Does the tranny need to get hotter to check it or did i let to much tranny fluid out. I am checking the fluid on what i think is level gound. What do you guys think. Thanks for the advise it helps me out the shop is not much help.

I took out about 2cups or 1 pint of fluid out of the tranny. With the temp at 150 it shows the level at the top of the cold mark. Does the tranny need to get hotter to check it or did i let to much tranny fluid out. I am checking the fluid on what i think is level gound. What do you guys think. Thanks for the advise it helps me out the shop is not much help.

The "HOT" band is based on having sump temp in the 175F - 180F range.

You'll want the level to be in the bottom half of that band. (You can be less than that if you never drive in cold temps.)

The bottom line is that trucks in hot climates need less, in cold climates need more because of the thermal expansion of the oil with temperature.

I will try to get the trans to 175 and see what the level is at. After draining the fluid out i have not seen the temp go much over 150. Does anyone know how much AFT will expand with each degree of rise in the temp. I think that i will be at the bottom of the hot mark if i could get the trans up to 175. Thanks for the info