In-Radiator ****** Cooler AND Standalone?

[TwoBobsKJ]

So I've been thinking about this for a week or so...

I have an '03 Renegade with the 42RLE ****** which has the standalone cooler in front of the radiator - and I want to ensure the trans fluid stays nice and cool while towing the boat and during "extra-curricular activities."

How about this: Rather than buying another ****** cooler to supplement the one in front of the rad why not get a radiator for an '02 with the in-tank trans cooler and put it in-line with the stand-alone factory trans cooler I have now? I don't know in which order I would connect the hoses (in other words run the outlet from the trans to the rad cooler, then to the standalone inlet, out to the rad then to the transmission inlet or a variation of that...)

What say you all? Any potential here for an effective cooling system for the trans? Or am I trying to put a square peg in a round hole...? Or is last night's "adult beverage" warping my thinking? arty52:

With anticipation...

Bob

 

[j-rod]

im doing this on my XJ. adding an auxillary cooler in front of the rad. I have the in-rad cooler currently.

Im planning to run out of trans - in aux - out aux - in rad - out rad - in trans. with my temp gauge tapped in the exit trans line.

 

[J-Thompson]

Just food for thought
On my TJ ,4.0 & TF999 auto, I did the 2 cooler set up
From trans to radiator then to aux. cooler then back to trans
I had a temp gauge on the return or cool side as per the instructions
it would run near 160-170* all day long
I was told by a "mechanic" to "skip the radiator because it will heat
the trans fluid"
So I did and he was right
Now on the hottest days I can not get above 160*
and just for back up I have an 8" fan with a switch
Never really needed it

 

[LibertyTC]

x2 as above.
The larger stand alone cooler with thermo electric fan, mounted up front, is best.
I am currently installing a a PML 42RLE aluminum pan, with magnetic drain plug.
This will allow 6.5 quarts (1.5 above stock) to be drained more frequently without having to drop the pan. Keeping the friction modifiers fresh in ATF+4 is a real benefit.
I also use LubeGArd red which reduces friction/fluid temps http://www.lubegard.com/~/C-112/LUBEGARD+Automatic+Transmission+Fluid+Protectant
40708[/ATTACH]"]

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Fluid temps are expected to drop with new ****** pan. While towing, this will help too.

 

[tjkj2002]

Just food for thought
On my TJ ,4.0 & TF999 auto, I did the 2 cooler set up
From trans to radiator then to aux. cooler then back to trans
I had a temp gauge on the return or cool side as per the instructions
it would run near 160-170* all day long
I was told by a "mechanic" to "skip the radiator because it will heat
the trans fluid"
So I did and he was right
Now on the hottest days I can not get above 160*
and just for back up I have an 8" fan with a switch
Never really needed it

Fine for your 3 speed trans but the 42RLE and 45RFE requires the temps to reach normal operating temps before the trans will shift into OD and the lockup clutch to engage.

Running the trans fluid to a in-radiator cooler then looping it through a stand alone trans cooler is the best and warming the trans up faster(winter operation) and is better at maintaining a steady trans temp,much better setup to handle temps spikes in which a stand alone cooler does not handle very well on it's own.


Here in the Rockies the KJ's with 42RLE's and there stand alone trans coolers would have to stop alot,even before we even reached the trail head, because the trans temp light would come on.Even those KJ's that had the HD cooling with the 42RLE would still suffer the same overheating.No one with a 45RFE ever had that issue.

 

[LibertyTC]

Ah yes the dreaded 42RLE ****** light..
I wonder what makes the 45RFE run cooler than the 42RLE ??
I sure hope the PML will cool fluid better and offer a bit more capacity.
Maybe that is just what it needs to keep the light off?

 

[rockymountain]

Ah yes the dreaded 42RLE ****** light..
I wonder what makes the 45RFE run cooler than the 42RLE ??
I sure hope the PML will cool fluid better and offer a bit more capacity.
Maybe that is just what it needs to keep the light off?

Probably because its like Lou Ferrigno compared to Peter Pan pushing a loaded dolly cart?

 

[retmil46]

That is one of the blessings of having a CRD - the 545RFE ****** behind that diesel - but then Chrysler had to go muck it up and put a weak-kneed gasser torque converter with an entirely wrong stall speed in it.:favorites68:

The CRD's with the 545RFE ended up with a combination air cooled stand-alone ****** cooler/A/C condenser as well. And as was mentioned above, the 545RFE also won't shift up into the overdrive gears in cold weather until you've driven a ways and the computer decides that the fluid is warm enough.

Difference between the 42 and 545 might be the computer controls and electronics in the 545 - the computer will actually modify the way the ****** shifts and operates based on fluid temp to keep it from overheating - something like seven different modes - ie, it will "derate" the ****** to protect it.

A radiator ****** cooler won't cool the fluid any lower than your coolant temp. On my CRD, with a 170 F thermostat, I'd count a radiator ****** cooler as a blessing - a few minutes warmup in really cold weather would eliminate the cold shift syndrome - and a small aux ****** cooler to help keep things under control in summer - would make life much simpler.

But on a gasser, with a thermostat set for over 200 F - when you're wanting to keep the ****** fluid at a max of 180 F or preferably well below....

Guess it depends on what's the bigger inconvenience to you - putting up with the cold shift syndrome in winter - or having the ****** overtemp light come on in summer or when towing or playing off-road.

With an extra stand-alone air-cooled aux ****** cooler, there's a few simple things you can do to alleviate cold weather problems - some ****** coolers such as B & M have an internal bypass that will port the fluid around the cooler section if it's too cold - you can install a simple manually operated bypass valve in the lines to the aux cooler, such that you can easily take it off line in cold weather - or the old shadetree mechanic approach, just tystrap a piece of cardboard around it for the winter.

 

[kskj]

So I've been thinking about this for a week or so...

I have an '03 Renegade with the 42RLE ****** which has the standalone cooler in front of the radiator - and I want to ensure the trans fluid stays nice and cool while towing the boat and during "extra-curricular activities."

How about this: Rather than buying another ****** cooler to supplement the one in front of the rad why not get a radiator for an '02 with the in-tank trans cooler and put it in-line with the stand-alone factory trans cooler I have now? I don't know in which order I would connect the hoses (in other words run the outlet from the trans to the rad cooler, then to the standalone inlet, out to the rad then to the transmission inlet or a variation of that...)

What say you all? Any potential here for an effective cooling system for the trans? Or am I trying to put a square peg in a round hole...? Or is last night's "adult beverage" warping my thinking? arty52:

With anticipation...

Bob

I put the 02 radiator in my 04 in line with the stand alone cooler. Never had the trans light come on again. Drove Imogene pass two years in a row. First year i had to stop two or three times to let the trans cool down. With two trans coolers light never even came on. That's 13,200 foot climb in 4 low. We also get cold winters here. 15 below last year and not one cold shift problem.

 

[Ry' N Jen]

Our Heep also suffers from the transmission over
heating while wheeling!
I have been looking into adding an additional electrically
cooled stand alone cooler to our Rig, but there is not enough
room between the radiator and the grille. The centre support
for the hood release is in the way as well as the ****** little
stand alone factory ****** cooler.
After calling several aftermarket parts houses and having discussed
in detail with them, I am going to replace the factory '04 rad with
either a stock 2002 style rad or an aluminum rad with built in transmission
cooler and then add the engine diven H/D mechanical fan.

Cooling oil and or transmission fluid through the engines cooling system and then through an auxiliary fluid to air cooler is more efficient than just an to oil air heat exchanger cooling matrix.

 

[LibertyTC]

I think in Ryan's future I see a PML pan soon.
If the dreaded ****** light does appear again after new pan, with a drain plug, you can re-fresh the 6+ quarts ATF+4 and restore some of the friction modifiers from the burnt fluids.
I am hoping with lubegard red (2 bottles) and the new PML pan, I can wheel/tow my rig hard in warm temps, and I hope not to see the ****** light on !
Time will tell..
40751[/ATTACH]"]

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Install next Sat. (finally)

 

[retmil46]

Our Heep also suffers from the transmission over
heating while wheeling!
I have been looking into adding an additional electrically
cooled stand alone cooler to our Rig, but there is not enough
room between the radiator and the grille. The centre support
for the hood release is in the way as well as the ****** little
stand alone factory ****** cooler.
After calling several aftermarket parts houses and having discussed
in detail with them, I am going to replace the factory '04 rad with
either a stock 2002 rad or an aluminum rad with built in transmission
cooler and then add the engine diven H/D mechanical fan.

I had the same dilemma on my 05 CRD - so much junk under the hood the way they shoehorned that diesel in there, plus an intercooler, and most likely not having the option of using a gasser radiator due to the different plumbing configuration on that diesel.

What I ended up doing was using a two-pass fin and tube rail cooler - 2 1/2" wide by 18" long - from Permacool (now defunct). Up under the front bumper cover, there's a nice long opening in between where the front towhooks mount. I fabricated some simple mounting brackets and installed them on the inside mounting bolts of each towhook, then mounted the rail cooler to them.

Doesn't do too bad - here in San Antonio the other day, after a 22 mile drive to work, mostly interstate, at 2 PM with an outside temp of nearly 100 F, I checked the temps with an infared thermometer - 170 F on the ****** pan, 130 F coming out of the rail cooler.

Then again, I've also been blessed with a mechanical fan on that diesel - which I've upgraded with a Hayden severe duty clutch that engages at about 30 F lower air temp than factory - and replaced the 5 bladed metal fan with the 11 bladed nylon fan from a V6 w/ tow package.

There's enough room up under the front bumper cover that I'm actually in the process of swapping out that 2 1/2 x 18 two pass rail cooler for a four pass 5 x 15 cooler from Flexalite.

I'm going to save the rail cooler for my friend just south of Austin, who has a 2011 Wrangler Unlimited. He doesn't have an opening in the front bumper cover, but I'm thinking we can mount that rail cooler to the sway bar in between the engine and radiator, in close proximity to the OEM ****** cooler hoses. Maybe I'll be a nice guy and get him a Magnefine ****** filter as well.:gr_grin:

 

[J-Thompson]

Our Heep also suffers from the transmission over
heating while wheeling!
I have been looking into adding an additional electrically
cooled stand alone cooler to our Rig, but there is not enough
room between the radiator and the grille. The centre support
for the hood release is in the way as well as the ****** little
stand alone factory ****** cooler.
After calling several aftermarket parts houses and having discussed
in detail with them, I am going to replace the factory '04 rad with
either a stock 2002 rad or an aluminum rad with built in transmission
cooler and then add the engine diven H/D mechanical fan.

are you running in 4wd low and 1'st gear?
we have wheeled with some KJ's with the 42rle in the South Louisiana summer ,95* + temps
and running 4wd low and 1'st gear they did not get a trans temp light

 

[Ry' N Jen]

are you running in 4wd low and 1'st gear?
we have wheeled with some KJ's with the 42rle in the South Louisiana summer ,95* + temps
and running 4wd low and 1'st gear they did not get a trans temp light

Yes J, four low and in first gear.
Very steep, very long winding trails, and
high elevation at very low speeds.
Not going fast enough to force any air through
the oil cooler matrix.
No problems with engine coolant temp, just
****** temp!
We just follow the instructions written in the
owners manual to allow ****** fluid cool down...

And for that reason I want to switch to an 2002
rad with integral transmission cooler.

 

[J-Thompson]

Yes J, four low and in first gear.
Very steep, very long winding trails, and
high elevation at very low speeds.
Not going fast enough to force any air through
the oil cooler matrix.
No problems with engine coolant temp, just
****** temp!
We just follow the instructions written in the
owners manual to allow ****** fluid cool down...

And for that reason I want to switch to an 2002
rad with integral transmission cooler.

I have seen this issue with the JK's and people who claim to have
"done this type of wheeling before" and we find them in 4 high and trans
in Drive
but put them in 4 low and 1st gear and all is good

 

[tjkj2002]

I have seen this issue with the JK's and people who claim to have
"done this type of wheeling before" and we find them in 4 high and trans
in Drive
but put them in 4 low and 1st gear and all is good

Yeah when you get over 10,000' 4low and 1st gear is not enough to keep the 42RLE cool.A whole nother story closer to see level.

 

[LibertyTC]

With no air movement through rad like at slow speed wheeling and climbs.....
I can almost bet if you took the hood off, you would not get ****** light.
Unbelievable how much under the hood heat is present in those conditions.
I think our hoods could use some vents/louvers.

 

[tjkj2002]

I think our hoods could use some vents/louvers.

:waytogo:

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When the fan comes on you can not hold your hand above them for but a second.

 

[J-Thompson]

Yeah when you get over 10,000' 4low and 1st gear is not enough to keep the 42RLE cool.A whole nother story closer to see level.

explain?
the temps are cooler ,by a long shot
I am talking 95*+ and AC on
with instructions like
"if you want to make this climb under your own power you will need to find
the rev-limiter other wise take the by pass"

I dont see elevation effecting temps
not by that much
believe me if you wheel some of our trails in the summer it brings a whole new meaning to the term "hot as he77"

 

[J-Thompson]

:waytogo:

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When the fan comes on you can not hold your hand above them for but a second.

get you a long skinny one and mount it just behind the fan
allowing some of the hot air to be blown up and out of it
trust me
we can not put the windshield down EVER