I have installed a tranny temp guage and was wonder what is the best temp for a tranny to be running at. On a cool day it will run around 130 degrees, when it is warm out it runs around 140-150 and when I am driving in town it gets around 160 but not usaully over. I was thinking about installing a tranny cooler but I have heard running a tranyy to cool it can damage it . If I install one should it be installed before or after the tranny cooler in the radiator.

 

160 is kinda high, 135 is about what you want to see. Never heard anyone claim that a trans cooler is bad, thats insane. Install the trans cooler after the radiator cooler, unless you get one of the very large ones, then you can just use it alone.

 

The people that are telling they are bad probably live somewhere that is very cold and are not running it through the radiator cooler. I have heard people say their fluid turned to sludge during the winter. I have never seen this happen but that is one of the reasons for leaving the radiator in the loop from what I have read. The cooler should be hooked up after the radiator for maximum cooling.

 

Typical petroleum-based ATF life starts dropping above 170 degrees F. At the typical radiator temp, that's no problem. However, stop & go driving, towing, etc., will shift the recommended change interval from 100,000 miles to 15,000 miles. That tell you anything?

If you're seeing 160 F, no particular problem. Below 100 degrees, though, you start affecting the flow characteristics. If that's an issue, get a thermostatic by-pass valve that will only route the fluid through the add-on cooler when the fluid has warmed up.

FWIW, AMSOIL ATF resists break-down up to 270 degrees F.

IIRC, the old guideline for ATF life was, cut it in half for every 10 degrees above 170. At 250 degrees, you're talking about hours.

 

If i put the tranny cooler before the radiator cooler will it give me any problems other than not cooling the tranny fluid to its full potentiol. Just want to lower my temp around 10-20 degrees. Dont want to lower it more than it needs to be.