I will share my experience in this venture.
About a year ago, my water pump started seeping and I had wanted to add a trans cooler eventually anyway. Much searching here on the forums and I gathered parts galore. New water pump (gates) t-stat, belt, hoses, ZJ fan clutch, flush cooling system and heater core, etc.
Bought all new hard lines, then adapters to add a temp gauge with the sending unit right at the outlet via AN fittings. I had a local hose shop weld some AN adapters to the hard lines and add an AN adapter to a new stock style radiator. Got one of the Hayden coolers and mounted it in front of the radiator/condenser on the right side. I was using some aluminum tubing from Summit and purchased the 37 degree flair tool to make some of my own hard lines with AN ends too. I also added an in line filter, just a generic filter head that takes the same spin ons as the motor.
Routed the lines as follows: out of trans over the temp sender to the filter, to the cooler, to the stock cooler in the rad, and back home to the trans. After all of that horseshit, it ran hotter than before as far as engine temps but no overheating except for long idles. I had no previous bearing for trans temps but it seemed to match the engine in the city and cool way down on the highway.
This was "fall" in AZ. It did fine over the "winter" and the whole 2 weeks of spring. Then came the heat of summer and I was not comfortable with it anymore. I had developed some leaks in my homemade hard lines AN connections and It affected my A/C ever so slightly.
I planned another 3 day wrench session and got an aluminum radiator this time. I am a little over 200k now so I knew I should have done the timing chain last time but skipped it. New timing chain this time. I also occasionally got trans codes and a CEL and on 2 occasions it didn't go into overdrive on the highway. Shutting of and re starting solved it both times. I knew it was in need of a real good trans service (didn't do it when I added the cooler) so I got a filter,gasket and solenoid kit and stocked up on synthetic atf. I ordered a hose kit from Amazon for make your own stainless braided lines and replaced everything I did before. Moved the cooler down to the cross member and added some breather holes in the bumper. I also added a thermostatic switch in one of the extra holes on the filter housing for a future designated trans cooler fan.
Now everything runs cooler. The trans will still match the motor temps when it gets to the higher end (stop and go city or pulling trailer on a grade or wheeling) but for the mostly it stays a little cooler except for highway when its a lot cooler.
I know that there are other issues that I could address (gears) that would help. If I could lock the converter in second when pulling grades with the trailer (I over-pack, I know) I would like that too, but that's a whole different can of worms. I am gathering parts for another relay block to run accessories including the trans cooler fan and wouldn't you know, there might be a place in there for the right hand drive electric fan conversion. My radiator has a port for that t-switch as well.
I have noticed no ill effects from the spin on filter. I change it when I change the engine oil, top off the loss and that's it.
I was pleased with the Amazon hose kit too. Easy to build and leak free so far.
s Nazi rules about not being able to edit.
