that would be kind of hard since it says Trans Temp on the display. I can not believe yours get no higher, it seems to be impossible based on how the truck works.

also as for not shifting I am not sure about that. going up a hill it holds a gear and the temp rises.

 

When my tranny temps go up to the 210-220 range - the engine oil temp is in the 220 range, and goes down when the ascent ends. I've never seen it go much higher than that. My temps usually are reached after I've been on the road for a few hours and have done a lot of up and down on long grades with outside temps at around 90 degrees F. It's like the temps build up after some time. When I first get going and go up high grades with headwinds, the tranny temp is not a problem. Another thing, I try to keep up my speed between 60-65 MPH and try to keep it up on the higher end. In California, the speed limit for towing is 55 MPH but when crossing over to other states, the limit is much higher and if you drive slow, the semis will be on your ***.

 

So are you saying that the two pretty much coexist with one affecting the other? In other words, if you engine oil temps rise the trany temps rise with it and vise versa...if the oil temps go down, the tranny temps go down...correct? "EDIT" Everyone else, please keep your opinons to yourself, I'm asking Pedro Dog only...thanks!

 

One time, here in CO on a long steep grade with OAT @ 85 my Tranny hit 225 while I was in stop and go traffic in Woodland Park. That was with a stock tune. This year, under the same conditions, my tranny never got above 205 and I think it’s because I was using the SC Tow tune. My RPM's were usually in the 2100 - 2800 range and towing was effortless all the way up to 11000 feet. My TT loaded is around 5500lbs or so. PNW GUY, I would suggest using the tow mode on a tuner, it made a nice difference for me with the temps and my RPMs's were almost in diesel territory

 

They seem go up and down together but no at the same rate. My engine oil temps seem to stay over 200 in the 205-210 range even when the tranny temps go back down to the 170-190 range. I don't think one affects the other as much as that both engine and tranny are working hard on the grades and fighting headwinds.

 

It doesn't get any hotter while in tow/haul and pinned in 4th. Maybe rises 10-20* when going up a hill but it drops right back down. Maybe you don't have the heavy duty tranny cooler on your truck, check your build sheet. I know mine has it.

 

The engine oil is not going to go much lower than that because of the 203 tstat. If it were a 180 then the oil temp would go lower when the tranny temp does and it makes sense. Your oil temp can never go lower with the engine at 203 degrees (the engine temp) in normal operating conditions. That's my whole point of using a 180 tstat. The oil temp would be closer to the 180 tstat temp, and the tranny would follow. The engine oil is feeding off of the max tstat temp and will go higher under stress. The tranny is feeding off of the engine temps (not oil) and will go higher under stress as well. And BTW... 200-240 is perfectly safe for any tranny. 250-260 is borderline, and 270-275 is the danger zone. However, if you could keep the temps at 180-220, you would extend the life of your engine and tranny, not to mention all of your seals, rubbers and plastics would last longer as well too. My whole point of using a 180 tstat (if we could) is that your tranny would run that much cooler. I think that the engine block and tranny casing would stay relatively close and the fluid will follow...You have to admit, it's definately possible, thanks...you made my case, lol!

 

Here we go again, I knew you wouldn't be able to hold back. I don't see what a difference a 180 thermostat would make when we are talking about temps that are higher than 203, in either case, either thermostat (180 or 203) is wide open yet the temperatures continue to climb higher. Thermostats have no influence on higher engine oil or tranny temps once they are open, at this point, it's the engine cooling system limitations in the environment it is operating under. Pretty straightforward really.

Makes no sense that heat transfer would go from the coolling system to the the heat sink. Since the radiators are designed to get rid of heat, and the cases are just hot metal with very little heat dissipation capacity, it is counterintuative. Besides liquids are much more efficient at heat transfer than metal.

 

I respect your opinion, but may I remind you that you're still under oath, lol! (just teasing) And for future purposes, I'm very familiar with both liquid and air cooling. If you have xfire I can send you files of hundreds of documented benching hrs of scores and settings from my overclocked computers. I also have several competitive scores (up to that date) documented on Futuremarks website. That being said, I think it's safe to say that I warrant respect as well...thank you very much, lol! I haven't played much because of so many projects going on, my sig on xfire is RadioFlyer (aceofaces). I play the Crysis packs, IL2 1946 Sturmovik and fly WW11 airplanes (North American Top Gun Fighter Pilot School), bi-planes, and fighters as a student when I can afford it and I'm looking forward to a Combat USA trip next...wanna dogfight anyone, lol! But okay, no more of my opinions, nobody beleives me anyway so I give up, lol!

 

BTW...I've been doing lots of research on the pros and cons of using a 180 tstat because of this topic and the only cons are related to heating in freezing temps. I found that both oil temps and tranny temps dropped 10 degrees and oil pressure gains averaged a 7 lb increase (at operating temps) using a 180 stat. Not to mention no loss of power like the heatsoaked 203 and with or without tuners there were absolutely no reported codes popping up because of the 180 tstat, none! I'm pressed for time, but within the next couple of weeks I'm going to test the temp differences between the two myself with my truck at my friends shop. I'm working a few 12 hrs at night and a couple in the daytime and it's taking a toll on me so I going to let him get his hands dirty but I'll be there. Sorry to bring this back up but I don't like loosing, lol! I'm sure you've all heard the saying, "I may be left handed, but I'm always right"...well that's me, I'm left handed and I think I'm always right, lol!