I thought I would ask for a little in put here. My 99 psd had a problem running on the high side on the tranny temp (180 common to 220 ) sometimes higher.Did a complete flush, filter, deeper pan, amsoil fluid and saw little to no change.
I then put a new tow/snowplow tranny cooler on (stock was about 1/3 of the size. Now I have to see the temp get above 140. Is running the tranny too cool a problem? It nice to see cooler temp, but is this going to trouble for me in the long run? Thanks for the input.

 

Heat has the most damaging effect to an automatic transmission, so running it cooler is not going to cause any harm. In fact, I recall reading somewhere that for every 10 degrees you can lower a transmission's operating temperature, you can double its working life.

 

i've heard of trannys being a little sluggish when they get real cold in the winter.. but Marcus is right... heat is the only real "tranny killer" that i know of....

 

Fully agree with Marcus' input.

 

If you run where the outside temp gets below zero, you might want to consider routing the cooling lines through the radiator after it runs through the big cooler. Or run synthetic tranny juice; it's less susceptible to thickening.

 

Thanks for the input! I'm run synthetic in it now. Sure does the wallet and tranny good to be running cooler. Thanks again!