Putting a fresh built stock tranny back in an 06. I just did the coolant bypass, I got a mishimoto tranny cooler, now I'm wondering if I should direct fit the cooler or still run it through the exchanger back to the tranny. Important to know I live in PA and mostly run in the summer. Also, Mishimoto, in PA should I keep the thermostat in or take it out? Thanks in advance!!

 

I deleted mine and live in cold climates. Make your own lines with 8an lines and hydraulic hoses.

 

I'll have to delete it then, seems to be the better decision. Do I keep the thermostat in or out then on the mishimoto cooler?

 

I left mine out. I prefer a full flow cooler and did not appreciate the stock thermostat sticking.
I figured I would try it without and if I needed it I could always put it back in but so far having it removed works perfect. I did put an old voting sign in front of the radiator in the winter to help keep it warm (single digits). If I don't then the trans temp is around 100f. If I cover it then the temp runs 140-160.

 

So I guess that leads to the next question. The optimal trans temp should be 160-200? From my understanding ya don't want it too cool and obviously not hot. The mishimoto has a temp sensor in it, I think I'm going to leave that in because that's good till 140 and still run it through the heat exchanger, mounted on the block. Any other suggestions, different setup thoughts?

 

This is one of those things that you should research your own info and makes the best decision.
140-220 is an acceptable temp range for the trans. Using the exchanger keeps it more stabile because the coolant temp now has significant influence. I personally do not like the coolant raising my trans temps. With it deleted during the summer my coolant is at 195 and my trans is 150-160.
I have heard many time of heat destroying the trans but I have never heard failing due to running "too cool".I am sure its happened but the heat is a bigger issue IMO. 140 is the temp that ATF is effective (based on my research) If you tow then that TC will always make enough heat.
The Mishi trans cooler thermostat seems like a great improvement over the stock thermostat but I just don't care for restrictions and if its hot I want full flow to get her cooled down. I planned on putting it back in if she ran "too cool" but that has not been an issue so far.

 

I did the fleece coolant bypass, so there's no coolant to cool the tranny temp anymore. The tranny will solely be cooled by the mishimoto cooler. I think I'll leave the built in tranny cooler thermostat in for now and see where it leads me. I have mountains here in PA and tow during the summer, the truck sits in the winter for the most part. The truck also has 300+K, not really a factor but a variable in the equation I suppose.