What is the safe operating range for the tranny as far as temperature goes?

 

you'll get different numbers from different folks, but 220 max is about right

 

I have a 140*-280* Autometer trans temp gauge. In city stop and go driving 95* outside temp mine will get between 165-180*. Normal city driving gets to about 165* or so. Never really seen it over 185* even on the drag strip. Cruising empty on the highway it stays around or below the 140* low mark. My sensor is in the hot line going to the trans cooler.

 

Lets just say, at 250* most tranny fluids boil, and immediate failure is likely. Funny that the factory tranny temp light trips at 260* huh. At 190* the fluid has a 100% life expectancy of around 50,000mi. for every degree above that, the percentage of life is decreased by 1.5-2.0% depending on if you use synthetics are used.

 

If you really want to see high temps, just drive around in slow city traffic with a load without your TC locked. In fact, the highest reading I ever got was sitting in traffic waiting on a stalled wreck. I had just been ideling and moving very slow in D for about 10-15min. without thinking and just happend to look at my tranny gauge and it read 210* and I was empty. From then on, if I'm going to be sitting around waiting any longer than the time it takes for a light to turn green, I put the truck in N and and apply the E-brake if I have a load, or put it in park.

 

I can't remeber the source of this. I just know when I saw it, it caught my attention.

 

Thanks. Anybody running an extra tranny cooler?

 

P.J. - do you recall where the tempatures in that chart were measured (pan or hot line)?

- Jason

 

That chart is from Isspro. My Isspro gauges came with that chart on the instructions.

 

Oh, dude, no clue.

I can assume that a prolonged run above 250 or so (hot side) would have me questioning the longevity of my fluid. Since I don't have a trans temp gauge I don't have to worry about that kind of thing.
Ignorance is bliss......