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Project Unicorn - a light duty trail rig

Ok i have to chime in here. Both putting the cooler before and after the radiator can be correct for a given situation. The only way to determine where to put it is to use a trans temp sensor on the output side of the transmission to monitor the temp of the trans.The average for the aw4 should be between 150- 170. This is the optimum temp (according to the fsm i may be off a little). Does it always run at those temps no. Depending on vehc configuration, drivetrain load and the way you drive it can be higher (i've never seen it lower). The transmission needs to run at temp of 170 or so for many reasons the two main ones are that is the temp the fluid was formulated to operate at the other is that if the fluid is too cold below 150 it is not hot enough to burn out the moisture in the transmission that accumulates when the vehc is cooling down. If you run the cooler after the radiator depending on the size of the cooler the temps can actually get to cold and drop below 150. Of course this depends on ambient air temp. If you live in an area where the year round temp is warm this is not usually a problem. If you live somewhere that's warm in the summer but cold in the winter the chance of overcooling the transmission is possible in the colder months. Running the cooler before the radiator is the safest bet. Which is why most but not all manufactures run it that way. In this configuration any overcooling done by the external cooler can be countered by the hotter coolant in the radiator as it passes through the heat exchanger in the radiator. Bottom line always test get a transmission temp sensor look at the gauge you may not need a cooler (but you probably will) decide what configuration is best for you and the climate you live in and run it.
 
Maybe you missed the part about having a lifetime warranty on the JK.

They aren't going to sell us another car. They aren't going to sell us another transmission. They may install 2 or 3 or 9, but it will all be on them.

;)

Anyway, I'm bored with this subject. I can tell you the one thing I am not going to do is trans -> radiator, no matter what I end up doing. I won't argue that is the best way to get heat out of the radiator, but I do not feel it is the best way to get heat out of the car, and that's my end goal.

Yes, because no manufacturer ever screwed a customer out of a warranty claim.

If you think for a second you actually have a lifetime warranty and if anything ever breaks it will be replaced, I have some land to sell you.
 
I can tell you the one thing I am not going to do is trans -> radiator, no matter what I end up doing. I won't argue that is the best way to get heat out of the radiator, but I do not feel it is the best way to get heat out of the car, and that's my end goal.
The best way to accomplish this then is to get a high quality trans cooler with bypass. They let fluid bypass the cooler until it gets to a pre determined (usually 170-180) temp then opens up to use the cooler.
Then you can skip plumbing into the heat exchanger in the rad all together
 
The best way to accomplish thos then is to get a high quality trans cooler with bypass. They let fluid bypass the cooler until it gets to a pre determined (usually 170-180) temp then opens up to use the cooler

That sounds like a potential failure point?
 
That sounds like a potential failure point?

I personally have never heard of one failing but anything is possible.
I beleive they are designed to fail in open position but i am only familiar with B&M units.
They alos make external bypass valves that accomplish the same thing.
 
They alos make external bypass valves that accomplish the same thing.

I've looked into those, and the thing that keeps me from using one (namely the Derale one) is that the bypass doesn't open until the fluid reaches 180 degrees. I would rather shut off bypass at a lower temperature (150-160 degrees?), so that it's actively cooling before it is truly needed at temps higher than 175. However, I was going to use it in conjunction with the radiator heat exchanger, which would still be warming/cooling the fluid up to that point. In the end I just figured it was best to K.I.S.S. and not use it.
 
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Stopped by the shop and tossed on a new fan clutch, new bearings in the idler, tossed the water pump pulley and fan on, and the belt.

I forgot the stupid rubber grommet that goes under the radiator, so i guess saturday morning i'll finally finish up.
 
Ford did it? Thats reason enough for me not to. :roflmao:

Yea...those trans are just shy of bullet proof. Whatever ford did... It works.

I'm gonna go on a whim here and say if anyone knows how to keep shit cool, Cal has a pretty good idea n how it's done. Racing seems to showcase any flaws in a system.
 
shrug
i finished it and am back to driving the car

i don't even know what way its routing, nor do i at this point care. i cut one of the lines and patched the cooler in. after this last conversation here, zero ****s given about keeping the build thread up right now. getting good photos and writing it up is more work than the actual car stuff.
 
shrug
i finished it and am back to driving the car

i don't even know what way its routing, nor do i at this point care. i cut one of the lines and patched the cooler in. after this last conversation here, zero ****s given about keeping the build thread up right now. getting good photos and writing it up is more work than the actual car stuff.
Cal, don't let the drama of some of the XJ experts prevent you from posting the work you do. Some of us less informed newer guys to the XJ really appreciate your insight and the sharing of your knowledge. The success with my cooling system and motor/trans mounts are a direct result of the info you've shared here and on FB.
Dave
 
I appreciate your ac clutch writeup.
I will be doing that soon.
Sounds like Dave benefitted from your thread.

As I lye here in bed sipping on my makers mark & coke, listening to my wife snore in my left ear...the last thing I want to hear is a lot of estrogen enriched bitches bickering about trans/cooler/rad....trans rad/cooler.

Plz, cal....proceed. Some of us enjoy & learn from others.

Thankyou.
Mac
 
meh

after all of that work, power steering pump was leaking. replaced that today and did a degrease, we'll see if it stops marking its territory.

now that its cooling off i think its time to put this one aside for a while anyway. we have a DIY stroker kit for Dallas's MJ sitting at Russ's and I need to started prepping Big Bird for a return to duty.
 
Got bored yesterday, replaced my rear view mirror.

Gentex 261 from ebay. Simple install, 4 wires (12v/ground, 2 sensor wires).

Auto dimming, compass and temp. Works pretty well. Temp probe is clipped into the bumper where it should get a little but not too much air flow.

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