I need your assistance please. I have a 07 3/4 suburban with the 6.0 liter and the 4L80E transmission. I pull within the weight limit and always keep the rpm's up while pulling hills but continue to hit transmission temps in the 210 -235 range which I hear is not good. My suburban came with the factory trans cooler but am wondering if there is another replacement that installs easily.

Does the sending unit in the 4L80E transmission happen to be in the hottest spot of the transmission and maybe these temps are normal?

An example was Friday when I was pulling my 5000 lbs trailer in 69 degree tempature, the trans temp hit 225 on a short 3 mile climb. I had the RPM's up at 3500 to keep the converter locked

Does anybody else with this transmission hit these types of temps and what did you do to make it better.

thanks
Jeff <!-- google_ad_section_end --><!--IBF.ATTACHMENT_1011820-->

 

3500 rpm to keep converter locked? are you using the tow/haul function and keeping it out of overdrive? if not, these will cause high trans temps. towing 5k lbs uphill 3 miles is certainly a slight strain on trans to begin with. improper gear selection hurts too. also, how many miles does the current trans fluid and filter have? there are aftermarket coolers that install easy enough. summit racing, jegs,

 

when you have high rpms the converter is un-locked lower rpms in over drive helps keep the converter locked up and a locked up converter will give you a lower temp. only need to take out of overdrive if you are always looking and switching gears all the time. you can put in a bigger trans cooler and see if that helps. you dont want to be much over 200-210 on the trans temp. whens the last time you did trans fluid and filter. it should be done a 60,000 miles if your close to that you could do it sooner and see if that helps.

 

Ok. I thought higher RPM's was better. My suburban only has 25,000 miles on it. Still has the original trans fluid. I do use the tow haul function and on long climbs will drop it to 2nd gear.

 

keep in mind that a load will cause the temp to go up, its the amount of time that you keep it at those temps that is hazardous... if you are dropping back to normal with in a few minutes I would consider that normal.
If you are going to continue to haul regularly I would consider a larger aux cooler .

 

Since I already have the factory aux cooler, I decided to purchase the Mag Hytec transmission pan. Holds an extra 4 qtz of fluid which should help alot.

 

I give that a definite thumbs up. take some pictures of the install and show us how you did it if you can...could make a nice sticky how to...

 

Not necessarily,more fluid means more fluid to have to cool,also,I wouldn't put too much dependence on the factory guage(if thats how you're monitoring the temps)..getting a larger aftermarket trans.cooler,maybe find the schematics on putting in a torque converter lockup switch and an aftermarket trans temp guage would be your best bet,but adding a larger pan don't do too much for cooling.