2000chersport

I'll somewhat take you up on that..

33's and 3.55's:

With the fluid going through the radiator and the factory transmission cooler that had bent up fins my transmission must have gotten to 300 degrees because it started smoking and caught on fire. Thankfully in front of a shop that had a fire extinguisher. Had to get the transmission rebuilt and even had to replace some hard parts of the transmission that melted/deformed.

33's with 3.55, and 33's with 4.10, and 35's with 4.10:

Temps with fluid going through radiator and 1 (one) aftermarket HD cooler (one of the coolers pictured earlier) were around 175

35's and 4.10:

Temps with the fluid only going to the single HD cooler were around 200

To be edited to include my setup now with the dual coolers...

2000chersport

Oh yeah. And since I deleted where the transmission fluid goes through the radiator, my engine runs cooler now.

So my engine is running cooler and my transmission is running warmer, which is why I added the second cooler

djb383

I'm wondering how 175 tranny fluid temp would make the engine coolant temp warmer?.......am I interpreting that wrong? R u running a t-stat that is rated less than 175? What was engine coolant temp when using the rad cooler and auxiliary cooler? Wouldn't 175 fluid temp be preferable to 200-210?

autosurgeon

Hot automatic could mean it is slipping or the torq converter could be going bad.

CompleteCherokee

ideally you want a 3/4" gap between the radiator and anything in front of it (condenser, trans coolers, etc.)

PocketsEmpty

It seems that there is an issue with the trans itself. I have mine set up the same way, and moving my trans out of the radiator loop has helped a lot with my engine temps. I don't have a gauge hooked up, but with an IR gauge pointed at the trans pan, I haven't seen it go higher than 160 degrees. Granted, that's cooled fluid, but still quite a difference from 218 it was reading before that.

SteveMongr

With 4.10 gears and 35's it's going to run hotter than normal.
I suggest ditching the 'tube & fin' coolers and installing a single 'plate & fin'. It is much more effective/efficient.

For additional cooling, run the stock heat exchanger (in radiator) after the auxiliary cooler. Since it is in the cooler side of the radiator it will remove additional heat and will stabilize tranny temp in hot and cold climates.
When the stock cooler is plumbed first in line, much of the heat goes into the radiator rather than dissipated by the aux cooler.

djb383

Really?????.....that's just the opposite of the way Chrysler/Jeep mounts their auxiliary cooler in the XJ and just the opposite of the way Toyota mounts their auxiliary cooler in the Tundra I had and last but far from least, just the opposite of the way B&M says to mount their auxiliary cooler in what ever vehicle. Oh yeah, I almost forgot, I had a '92 Chevy pick-up that had a factory installed stacked plate type auxiliary tranny fluid cooler.....and GM mounted that auxiliary cooler inline with and AFTER the internal radiator tranny fluid cooler as well, not ahead of the rad mounted cooler.

SteveMongr

^ Correct and true. However there are numerous counterpoints, which would require a new thread. I have experimented with before-after cooler placement along with two temp senders (hot line and port on AW4) and an IR gun.
In a nut-shell, the 4.0 puts out tremendous heat and has an undersize radiator.
The AW4 and it's torque converter also puts out large amounts of heat, all compounded by going offroad. I prefer to dump the excessive heat first rather than be transferred into coolant/engine and spike the temps. Works good for me driving miles in soft sand and for highway.

djb383

I'm reasonably sure the automotive engineers and B&M's engineers have experimented as well and that is why they mount and B&M recommends to mount the auxiliary cooler AFTER the rad cooler.

The OP stated he was seeing 175* tranny fluid temp when he had the auxiliary tranny cooler mounted AFTER the rad cooler. Not sure why he changed .....175* fluid temp looks good to me and is good according to that chart......and I don't see how 175* tranny fluid entering the rad cooler could possibly elevate engine coolant temp.

Does the Jeep 4.0L really put out more heat than other motors? Does the AW4 and it's torque converter really put out more heat than other auto trannys? I do agree the rad is borderline dinky for the motor CID it has to cool.....but when all of the cooling system is well maintained and performing as it was designed, it does an adequate job 99.9% of the time and under 99.9% of driving conditions.

Like I said earlier, very few folks have installed a tranny fluid temp gauge so they can't monitor tranny fluid temp. For that very reason, I personally would not recommend a stand alone aftermarket tranny cooler nor would I recommend mounting a aftermarket auxiliary cooler ahead of the OE rad cooler and neither do the automotive engineers nor do the B&M engineers. Glad it works for u, though.

SteveMongr

I'm not the only one with this point of view.. And I am a firm believer in having a cooling system in top notch condition.

Here folks lost 5 vehicles in the last three months to fire from overheated transmission. The fluid vents and then ignites. Seems the engineers don't account for desert conditions in deep/soft sand. Every season a half-dozen vehicles burn to the sand.

The cool side on my radiator runs 135 F during street driving.

CompleteCherokee

now that's something you don't see every day in the wooded areas.

SteveMongr

^ Sugar sand is one of the most difficult terrains to deal with. Not from a drivers perspective but the vehicles. The torque converter slips a lower speeds and its common to run 1800- 2000 RPM and only be going 10 MPH. And the sand is 130F in summer.
I prefer to drive below the high-tide area where the beach is packed and full of whoops. Fun

djb383

Not even engineers can take into account 100% of driving scenarios.....SFB drivers invent new destructive driving scenarios everyday......some of those pics prove it. SFB syndrome has been known to destroy a Sherman tank in an afternoon. SFB will never be completely "engineered" out. Some folks cars should have a sticker on the dash that reads...... Warning: Do not drive like an idiot!

SteveMongr

^ I agree with every point you made in all above posts.
Are not we all re-engineering or rigs to some extent..