10-4 I wont be doing the 80 swap till later this summer. I was just worried that Ill be stalling 3k w/ a PI

 

I like to see tranny temps between 150*-190* but not over 190*. Pulling my boat (appx 6000# loaded) this year, I've been keeping an eye on tranny temp and it's slightly creeped above 190* and stays there. I plan on installed a larger cooler with a thermostat.

 

i run the factory and a b&m 40k run the **** outta it never gets above 180 before the second color it would get over 200 quick

 

I have a 258mm 3600 and a B&M 30K cooler, -8AN hose and bypassed radiator, with a 9 inch fan. Highway and normal driving in 95 degree weather in Denver it stayed around 180 and when Im beating on it will get to 210. I might add a second one when I move back to Texas next week.

 

I added a fan to my cooler and it helps after a track pass. I don't get in line to make a pass until it is back down under 170. After the pass depending on how long i was staged up i sometimes see 210. Driving around stoplight to stoplight it gets to around 190 but on the highway its 150-160. I think that the circle d probably generates more heat since it is looser than factory. Just my guess but i don't know crap about transmissions.

 

The GM engineer's say 200*-210* is normal temp for driving a HD truck with the 4l80e transmissions. Once you get over 240* you start hurting parts inside it. The perfered temp though is 200* at all times but if you pulling heavy loads then the tans will see higher temps. The is also motor temps 200-210 are normal for these trucks to run at.
145* and 160* are to low just like stated to low a temp is as bad as to high!

 

I run my 4l80e @ 140*- 160* depending on how much I'm abusing it. Was told by Jake to change the trans fluid a little more often as it will tend to not burn off the condensation... I also use straight up hydraulic fluid. Much much cheaper by the 5 gal bucket! For $35.00 per 5 gal I can afford a few more changes... my 2cts.

 

That's only the preferred temp on a 1600 stall converter running conventional ATF with emissions restrictions. Some light reading HERE.

Synthetic transmission fluid doesn't have the viscosity issues that regular ATF or engine oil has, it will lubricate and flow almost as well at -50*F as it will at 500*F. The clutches will break down at 230-260 degrees though. The hard parts will warp at 280-310. The only reason there is a "temperature suggestion" is for smog regulations. Cold conventional transmission fluid usually means cold engine, which means elevated emissions. Cold conventional ATF is also considerably thicker than when it's hot, which also increases emissions due to engine loading. This is why GM blocks TCC lockup until the fluid reaches 68.5*F...to ensure that the engine can make enough heat to lower emissions.

The transmission parts and fluid aren't going to be bothered by 130*F if you're not a cheapskate on your ATF. They probably wouldn't be bothered at all, but if you're running clear tractor hydraulic fluid you may as well be running some sawdust in there too.



TLR

Temperatures above 200 are only for emissions regulations.