Automatic transmission coolers???

Super 8

Legacy Registered User
City
Bozeman
State
MT
#1
Hello all,

I have a question for you automatic tranny owners. Do you run an extra tranny cooler or is the one built in to the radiator enough?

I have a 4L60E behind a 5.3L V8. I am using a be cool radiator with the build in cooler. I was considering using another tranny cooler in-line. Space is hard to find under the hood because of my a/c condensor, p/s steering cooler, and radiator. Is it overkill to add another cooler?

What are your thoughts????

Thanks,

Bill
 

1crazy-jeeper

What's a scrambler?
#2
What type of driving do you do? If you tow a lot, or do a lot of high torque low speed stuff maybe you should. If it's a DD then what you have should be enough. You make the call.
 
City
Cheyenne
State
wy
#3
When I put in my auto the shop said the one in the radiator did very little plus gets your antifreeze hot. He had me put in a good 12 x 12 cooler and I've never had any problem.
 

ibscrmbln

Ken Waters
LIFETIME
CJ-8.com Member
SOA Member
City
Topeka
State
KS
#4
I use both the radiator and an auxilary cooler that is placed in front of the radiator. The auxilary cooler is probably 6" x 12". I have an AW4 tranny. I also have a guage on it and occasionally on warm days in heavy rock crawling it will reach 240 to 250 degrees.

I have seen an auto setup in a CJ8 where only an auxilary cooler with a fan had been used. The person had attached it to the inner fender below the battery not all that far from the tranny. This was for a Hemi V8 and auto swap out of a Dodge truck.

Later, Ken
 

VinnyM

Rolling work in progress
City
Martinsville
State
NJ
#5
I like them......I had one on my 91 Explorer that my wife and I had & drove it for 175K miles, before I replaced it as the family DD last year. We never had any problems with the tranny, and I was told the tranny in the exploder was a POS ..... I vote put one on ... it can only help!

Vinny
 
Last edited:
City
Grand Rapids
State
MI
#6
I just ordered a B&M SuperCooler last night for my auto conversion. My radiator has the plugs in the bottom, too. However, after talking with some people, we reached the same conclusion Wyoming did...it'll just "cool" it using hot radiator fluid. I just had my TF999 rebuilt, and want it to last. Mine will be driven 80/20 road/offroad, and won't tow stuff very often.

Craig
 

Jimbob

Basic User
City
Germantown
State
MD
#7
For stock or near stock (inline 6) I would just use the one in the radiator. For a Smallblock I would use a high volume external cooler with a thermostatically controlled fan or the stock cooler and a smaller auxillary.
 

bigwalton

Picture cravin' AK Postal nut
Staff member
SOA Member
City
Dexter
State
MI
#8
One of the POs put on an aux cooler in front of the radiator on mine.

I really want to get a gage in that line to see what's going on, but as long as you don't drive in really cold climates I think it's a good idea. I eventually want to end up with a thermostatically controlled fan in a setup like Ken was mentioning.

You don't want to run one in the cold as you need to have the fluid up to a certain temperature to operate. Cold fluid can be as bad as overheating it from what I hear.
 

Marine-OpLaw

'ANTIQUATED' PackRat
City
Fredericksburg
State
VA
#9
I've seen suggested...

bigwalton said:
One of the POs put on an aux cooler in front of the radiator on mine.

I really want to get a gage in that line to see what's going on, but as long as you don't drive in really cold climates I think it's a good idea. I eventually want to end up with a thermostatically controlled fan in a setup like Ken was mentioning.

You don't want to run one in the cold as you need to have the fluid up to a certain temperature to operate. Cold fluid can be as bad as overheating it from what I hear.
To avoid the 'cold fluid shock' Eric refers to, I've read that folks run the fluid return line from the aux. cooler thru the radiator cooler to warm it back up before it hits the tranny. This would also act to cool down motor coolant. Makes sense to me.

Also, my prof. mech suggests aux. coolers as the way to go. While stock coolers work okay, using an aux. cooler is AT life preserving over the long haul - heat being the AT's primary enemy. Even though we do not pull anything w/ the YJ, he suggested putting one thereon for prolonging the tranny's life.
 

Jeepskate

Insane in the Membrane
City
Christiansted
State
VI
#10
I just put one in my recently back on the road CJ-7. It has AC, so there was no room in front of the rad, so I bought a Derale stacked plate cooler with fan and mounted it under the Jeep below the back seat area. I'm trying it with the fluid flowing through the rad cooler first, then into the aux. I did most of the run with some 3/8" stainless tube that I had leftover after abandoning the notion of making my own fuel & brake lines for the Scrambler. I need to pick up the thermostatic control for it before I bring it 'online' (Jeep is laid up right now getting a new trans pan gasket, high ratio trans throttle lever, and front driveshaft u-joints). Heat is an AT's worst enemy and mine is working pretty hard with 35's and the stock 3.31 gears (just got the 4.10's last week...not installed yet).

-Rodney
 
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