Transmisson Temp

[kg4buc]

I have a 2008 Silverado 4.3 V6 What Is the max Safe transmisson temp? I have seen 228 Deg in Traffic. Would like to know what others have seen Over 200 Seems High to me.

[tbplus10]

228 is still in the safe range.
If I remember correctly most trans fluid doesnt start breakdown until around 270, but that depends on brand, age, additives added, etc.
It wouldnt hurt to put an inline aux trans cooler on, they can be purchased for under a $100 at most auto parts stores and can reduce temps as much as 20deg in traffic(even larger reductions can be seen on open highway driving) depending on where its placed.
And certain additives are pretty helpful at reducing friction.
It's almost impossible to cool off an automatic transmission to much.

[PontiAddict]

228 is still WAY too hot in terms of longevity. A well cooled transmission should be no hotter than an engine, and sometimes as low as 160. 210 is MAX in my opinion. Keeping the trans in the range of the engine temp, and even just slightly cooler will prolong the useful life of the fluid at least twice over, especially with Dexron III

Highly recommend looking into an auxiliary cooler. B&M is a good company.

[silveradotrailblazer]

Mobil 1 makes a synthetic automatic tranny fluid which will run cooler and not break down as easly. It can be purchase at walmart or most parts stores. Also Earls make great coolers in just about any size you need.

[04silverado35008.1l]

Yeah that seems really high to me. My allison in my 3500 silverado never goes above 200 when I'm pulling my 28' enclosed trailer loaded up w/ my car and equipment. I'd see about getting a tranny cooler is your truck doesn't already have one.

[tlperry68]

When I pull my 33' trailer in 100 degree heat the tranny stays around 200 degrees. I see that the tranny temp typically stays about 80 to 100 degrees hotter than the ambient temperature.