Installing trans cooler

[jmnetus]

I am probably going to order this transmission cooler: Amazon.com link

People seem to like it on their Wranglers - any thoughts on installing it on my Liberty? Will having the factory transmission cooler installed change the installation? This will be the first time I've tried installing something like this, so any info from people who actually know what they're doing is helpful. Thanks!

 

[Josh]

There lots of good info here:
http://www.jeepkj.com/forum/f196/radiator-******-cooler-standalone-49142/index4.html
I'm sure others will have opinions about weather to replace the facory cooler with an aftermarket one or run them both in-line.

 

[Ry' N Jen]

I'd just install a rad with an in rad ****** cooler and then if you are into wheeling allot just plumb in the factory stand alone ****** cooler as well.
In most cases the in rad ****** cooler is enough as it cools more efficiently than a stand alone air to fluid cooler.

 

[jmnetus]

Yeah, I'm getting a cooler because the transmission temp idiot light has already come on while wheeling, and it wasn't even a hot day. It was partly my incompetence in shifting to 4Lo later than I should have, but... I'd like to stick some extra cooling on there just to be safe.

I doubt a radiator replacement is in the budget right now, and I think a better-placed standalone cooler in series with the existing cooler will get rid of the light problem. I hope.

 

[jmnetus]

That thread does bring up one issue though - will this overcool and prevent the 42RLE from hitting overdrive (in normal driving)? I can't see it overcooling that much, but if it does that would be a big problem.

 

[lautinjr]

I am probably going to order this transmission cooler: Amazon.com link

People seem to like it on their Wranglers - any thoughts on installing it on my Liberty? Will having the factory transmission cooler installed change the installation? This will be the first time I've tried installing something like this, so any info from people who actually know what they're doing is helpful. Thanks!

I have that exact cooler installed on my car as a PS cooler. I must say even with out a Fan on it she heats up pretty good with good transfer. I wouldn't use it solo on a Trans though probably won't be big enough.

 

[TwoBobsKJ]

A replacement radiator is cheaper than a new transmission...

For less than $200 you'll have a new radiator AND enhanced cooling for your ******. RockAuto just posted a new discount code in the vendor section. Use that and save even more.

BTW, I bought the fittings & hose from my local NAPA to do the plumbing for this mod and spent less than $15 and about 30 minutes of my time. ****** runs significantly cooler now when I'm wheeling and seems to operate more smoothly onroad too - but that could be my imagination. I still want to add the mechanical fan and HD shroud...

Bob

 

[Ry' N Jen]

A replacement radiator is cheaper than a new transmission...

For less than $200 you'll have a new radiator AND enhanced cooling for your ******. RockAuto just posted a new discount code in the vendor section. Use that and save even more.

BTW, I bought the fittings & hose from my local NAPA to do the plumbing for this mod and spent less than $15 and about 30 minutes of my time. ****** runs significantly cooler now when I'm wheeling and seems to operate more smoothly onroad too - but that could be my imagination. I still want to add the mechanical fan and HD shroud...

Bob

What Bob said!

You are better off getting a rad with th the in rad ****** cooler!
Cools much better than an air to fluid cooler.
Them be the facts!
Stand alone air to fluid coolers just don't cool as well as fluid to engine coolant ****** coolers do!
Better off to buy a rad with an integral ****** cooler.

 

[LibertyFever]

Now please correct me if I'm wrong but doesn't the stock Liberty come with only an electrical rad fan? If you add a ****** cooler shouldn't you also upgrade to a mechanical clutch fan and new rad shroud too?

My 04 Liberty Sport gasser has a factory trailer package which includes an external ****** cooler and the mechanical clutch fan and new rad shroud. It still occasionally overheats on the trails and on long highway hill climbs but that's due to a failing electric fan assembly.

Does the engine computer also have to be updated to tell it there's a ****** cooler?

 

[jmnetus]

My Liberty has the HD cooler/PS cooler/trans cooler on it already, but that hasn't been enough to stop the transmission temp light from coming on when doing low speed wheeling (I should be in 4Lo, probably - rarely had to do that on my XJ though!). I'd love to put in a radiator with hookups for transmission cooling, but right now with extremely limited budget I think the product in the first post is the best I can do - increase the surface area that is cooling the transmission at least.

Experience shows there's a decent chance I'll need to replace the radiator down the line anyway - at that point I'd get a rad with a trans cooler.

Shouldn't need to mess with computers - just route the transmission fluid through the new cooler.

 

[TwoBobsKJ]

My Liberty has the HD cooler/PS cooler/trans cooler on it already, but that hasn't been enough to stop the transmission temp light from coming on when doing low speed wheeling....

So you have the mechanical fan, electric fan AND the extended fan shroud? If so then something isn't right. Either your viscous fan clutch isn't engaging the mechanical fan, your electric fan isn't kicking in or a combination of the two. You shouldn't be experiencing trans temp problems if you're in 4-Lo and in 1st gear when wheeling with the HD system working properly.

BTW, virtually all KJ gassers through '05 had the power steering and trans coolers from the factory. The '06 and '07 models were hit and miss though.

Bob

 

[jmnetus]

Nah, isn't hasn't been a problem yet when I go into 4Lo. What I'd like is it to be less of a problem without going 4Lo - it overheated on just a steepish dirt road that I feel shouldn't be an issue in 4Hi.

Build sheet says I have:
NHFP Power Steering Cooler
NMCP Heavy Duty Engine Cooling

I haven't really closely inspected the guts of a Liberty without, but yeah, I think I have the shroud and the mechanical fan.

 

[jmnetus]

So, looking into things more...

I think surface area shouldn't be an issue - the factory transmission cooler is the long thing on the front and bottom of the radiator, right? (The PS cooler is the smaller standalone cooler off to the right, then.) That thing already takes up a good bit of surface area.

I'm wondering if perhaps what I really want is to install an inexpensive electric fan down by the transmission cooler, switched so I can turn it on when I will be doing lower speed wheeling that doesn't get enough air down there. Anyone done something like this?

 

[tjkj2002]

So you have the mechanical fan, electric fan AND the extended fan shroud? If so then something isn't right. Either your viscous fan clutch isn't engaging the mechanical fan, your electric fan isn't kicking in or a combination of the two. You shouldn't be experiencing trans temp problems if you're in 4-Lo and in 1st gear when wheeling with the HD system working properly.

BTW, virtually all KJ gassers through '05 had the power steering and trans coolers from the factory. The '06 and '07 models were hit and miss though.

Bob

Nah, isn't hasn't been a problem yet when I go into 4Lo. What I'd like is it to be less of a problem without going 4Lo - it overheated on just a steepish dirt road that I feel shouldn't be an issue in 4Hi.

Build sheet says I have:
NHFP Power Steering Cooler
NMCP Heavy Duty Engine Cooling

I haven't really closely inspected the guts of a Liberty without, but yeah, I think I have the shroud and the mechanical fan.

A fully functioning stock cooling system in KJ's with the 42RLE will never forgo the trans overtemp from coming on in 4hi,even with HD cooling.The only way to stop this issue is to go in 4low or modify the trans cooler via adding a radiator with a built in trans cooler.

Here in Colorado most trail runs with KJ's with the 42RLE we had to stop due to them overheating while still driving to the trail in 2wd on paved roads,even with HD cooling.None of the KJ's with the 45RFE with only the in-radiator trans cooler never had these issues.

 

[TwoBobsKJ]

I don't have the mech fan/HD cooling system. I did put in a radiator with the in-rad trans cooler and have plumbed that inline with the factory standalone cooler. Glad I recently did that mod as last Saturday I went wheeling and with the temps being in the upper 80s/low 90s and not a breath of wind things got pretty warm but the trans temp light still didn't go on.

I've never had the trans temp light go on while wheeling - but I've always been in 4-Lo. :shrug:

Bob

 

[J-Thompson]

Nah, isn't hasn't been a problem yet when I go into 4Lo. What I'd like is it to be less of a problem without going 4Lo - it overheated on just a steepish dirt road that I feel shouldn't be an issue in 4Hi.

Build sheet says I have:
NHFP Power Steering Cooler
NMCP Heavy Duty Engine Cooling

I haven't really closely inspected the guts of a Liberty without, but yeah, I think I have the shroud and the mechanical fan.

Your problem as stated above will only be cured
with a better radiator that has a good trans cooler
built in
You have the 42RLE trans and the 1st gear is not low
enough so to make it go the trans "slips" and thus generates
heat
You know this however
If you lower your final drive gear ,4wd low, the problem
goes away

 

[jmnetus]

OK, so the opinion here is that even with increased airflow to the existing cooler the transmission will still overheat?

It certainly does bug me how 'high' 1st gear is on the 42RLE. Barely keeps me at 30mph down steep pavement. Oh well...

 

[tjkj2002]

OK, so the opinion here is that even with increased airflow to the existing cooler the transmission will still overheat?

It certainly does bug me how 'high' 1st gear is on the 42RLE. Barely keeps me at 30mph down steep pavement. Oh well...

Adding a fan to the OEM stand alone cooler will delay the problem at best.Good luck getting a AUX fan mounted down there anyways,no room for it.

 

[Ry' N Jen]

Yeah, not much room between the vehicles grille and the A/C condensor-radiator.
You are going to have to modify/cut down the inner part of the grille oppening to
accommodate the bulk of the Auxilary transmission cooler and electric fan assembly.
Allot of work.

If I were you I'd just wait a little longer and wheel a little easier and save up and
purchase a replacement radiator with the factory built in transmission cooler.
Then plumb in the exsisting stock stand alone ****** cooler and you will have a good
setup with less hassle then trying to fit the fan several times to get it to fit properly
and clean.
Not to mention that an engine coolant to transmission fluid cooling system
(liquid to liquid heat transfer) will out perform the additional stand alone Air to
fluid cooling matrix/system.
And in the end it's just more cost effective.

 

[jmnetus]

Fine, fine, I give up... I'll look into getting a radiator with in-rad trans cooling. Anyone have a good one, aftermarket or OEM, that you recommend I look into? One you have personal experience with would be great. Thanks...