The Chrysler Minivan Fan Club Forums banner

Add-on Tranny cooler install question

34K views 45 replies 13 participants last post by  tcwagner1 
#1 ·
I am going to be towing a 2000 lb camping trailer with my '05 T&C so I am going to be installing an add-on tranny cooler as soon as it warms up a little (and flush and replace the filter while I'm at it). My question is should I place the add-on tranny cooler before or after the existing in-the-radiator tranny cooler? It would probably cool the tranny fluid more if installed after the existing one during the summer, BUT would that keep it too cool in our cold Minnesota winters?
 
#2 ·
If the transmission lines run through the radiator, then once the engine warms up, the temperature of the tfluid is going to be 190 - 210 DegreesF.
Because that is the temperature of the Coolant in the radiator (the last heat source the engine will se before going back to the tranny).

I was once told by a mechanic/engineer wiser than me, that the reason that you have auxillary tranny coolers is to get the temperature of the Tfluid down to where the coolant could actually cool it off, not where the tranny fluid would actually start to HEAT the coolant in the radiator. (ie the transfer of heat to antifreeze w/o the tranny boiling the afreeze)
He gave me a lot of technical details, about thermal -dynamics, and when he saw my eyes glaze over he just said, put the acessory cooler in the line before the radiator.
Hope that helps
 
#4 ·
You contradict your own logic. If the radiator will warm the transmission oil to 200 degrees, why would you put the aftermarket cooler in place before the radiator integrated cooler? Then, no matter how much cooling the aftermarket cooler does, the radiator will raise it back to 200 degrees.

A couple of points:
1) First, there is little radiator fluid-to-transmission oil heat exchange. There is a tiny bit, but not much. Much more heat transfers via the air flow than via water-to-oil heat exchange.
2) Secondly, the aftermarket cooler should always be the last stop for the oil on the way back to the transmission and it should always be the most forward in the airflow, so attached to the front of the other radiators. That way it gets the coolest air right before returning to the transmission.
3) The one exception to this rule is if you live in the arctic tundra and air temps are well below freezing all day. But if that were the case, why do you have an auxiliary cooler?
4) Lastly, look closely. If your car has air conditioning, the transmission cooler is probably integrated with the AC condenser, not the radiator.
 
#3 · (Edited)
Scoot over to the Trailer and Towing threads for more info. We just got done hashing this all out.

And if you are worried about too much cooling, your transmission will shift just fine with transmission fluid down to around 20 below F. After all, doesn't it shift just fine when the transmission is cold in the winter for the first mile? The transmission will quickly warm it's self up, just as fast as the engine.
 
#6 ·
I don't know the layout on a 2002, I have had 2005 and 1990, but for the radiator kind, I would definitely bypass the radiator and go to the auxiliary, Reason being it can clog so easily. I would look for the largest one that has copper or aluminum round tubes running through it, because it is much harder to clog with particles and burn up the transmission. I have had my 1990 bypassed for years and it works great. On plugging the old one, just reroute one of the hoses you disconnect to the other nozzle on the cooler and it is plugged. My 2005 cooler, not in the radiator from the factory, works so well, that after a long drive, I can take the fluid out on the stick an put it directly on my hand, it is maybe 100 degrees. It is great.
 
#7 ·
On the 2005 and up the cooler is part of the AC condensor if its a 2001 - 2004 the cooler is separate and inbetween the AC condensor and the radiator.
Hank
 
#9 ·
What?
 
#10 ·
None of our gen 4 vans have the transmission cooler as part of the radiator. Its a separate unit 2001 - 2004 and built into the lower part of the ac condensor 2005 and up.
Hank
 
#11 ·
The rubber cooling lines on the non HD cooling 02 run to the drivers side of the radiator and passes by it.They are not running into the radiator.I dont know where anyone would find extra space to put an aux cooler in front of the AC condenser,its pretty far forward as it is.Any moderate bumper bumping with a high stepping 4x4 could mash up the trans cooler pretty bad and then you arent going anywhere.
 
#12 ·
As mentioned, I have a 2005 with a 3.8 and the transmission cooler is part of the AC condenser, apparently, and it works very well. You might check with the dealer, or your paperwork and see if your van came with the towing package. If it did, you likely have all the cooling you need. But if you want more, you will probably have to pull the front grill and mount it directly to the AC/Transmission cooler with kits that usually come with these coolers.
 
#14 ·
Here is my opinion ,fist the water near the bottom of the radiator is probally a bit cooler than 190 to 200 degrees ,except for thoes extreme days ,stop and go traffic ,other wise if you had 220 plus degrees out from the enging and just 200 back into the engine ,it would probally over heat.

I do not have the internal cooling in my rad,its just a aux cooler from the factory (alumiumn) made by long mfg,it has a simple by pass built in that by passes the cooler in cold conditions allowing the trans to warm up.

If it were my choice ,I would of liked to have the internal cooler to help transfer that first bit of heat out,water to oil transfers better than the oil to air type.then to the aux cooler and the back to the trans ,,make sure its installed in front of everything else ,So right now ionly have the factory stock cooler oil to air and added a 12 x 12 cooler in front ,I put it lower as to help protect the condenser from road debris .Plus if you noiced that your trans will not shift until the oile heats up to a min temp,and if it does overheat the computer program will call the engine coolig fan on.

my veh 2001 d grand awd
 
#15 ·
Follow up...

On the 2005 and up the cooler is part of the AC condensor if its a 2001 - 2004 the cooler is separate and inbetween the AC condensor and the radiator.
Hank
Ok, this thread is a few months old, but this post gave me a new question to think about. I've got a 2001 GC 3.3L with about 80,000 and no towing package. I just picked up a 2000# Jayco camper I intend to tow on reasonably short trips(I'm in IL and would probably only go on Midwest trips for the next 2 years or so...no mountains or desert). I am going to add the trans cooler, but from what is posted here, it looks like there is already a seperate trans cooler in use. From what I had read already, I was under the assumption that my trans coolant ran through the radiator. My plan was to route the fluid through the radiator then into the aux cooler(mounted in front of the radiator). Assuming there are 2 seperate coolers, should the new cooler be added to the existing one or should it replace the existing one? If added to, should the aux cooler still be placed in front of the radiator to get the best air flow?

Thanks,
Bill
 
#16 ·
It sounds like there is a lot of debate about what the trans fluid does and does not flow thru. I know that my 2000 (3rd gen) van came from the factory with coolant running thru the radiator and into the Mopar aux cooler which is in the very front, attached to the main A/C condensor.

I do not know what the different configurations are/were across so many model years. I suspect they changed in '01 (for the 4th gen) and in '05 (refresh), and again for the '08 (5th gen) but maybe also in-between. But from what I read they could be any 1 or more of the following:
1. Bulb-type oil-to-water cooling in a small portion of the engine radiator.
2. Oil-to-air cooling in a small dedicated aux trans cooler (usually in front of the A/C condenser.
3. Oil-to-air cooling in a portion of the A/C condensor.

Regardless of what you have, I would think that if you have any 2 of these 3 items, your transmission is sufficiently protected up to 3800 lbs. If you only have 1 of these items (probably #1), you should add an aux cooler (#2). IMO, this aux cooler should be placed after the radiator cooler. But in reality, I don't think it really matters. If you are really worried about the Minnesota winters, then get a high-end cooler that will automatically bypass the cooling fins until it warms up to a certain temp.
 
#19 ·
What is WDH kit. :ask_wsign
 
#17 · (Edited)
If you buy the large heavy duty cooler (As I mentioned, I prefer the ones with round tubes that do not clog easily) AND your fluid goes through the radiator (I assume you can tell if it does) I would BYPASS the one in the radiator and go through the add on unit only. I used mine in the mountains of W Virginia with lots of snow and cold for years with no problems. I would bypass any cooler that went through the radiator since I lost several trannies due to clogging of these stupid little coolers. Just run one of your old hoses from the output to the intake of the radiator line and seal it up that way. Run the new hoses from the tranny to the cooler and back, attach to the front of the radiator, or have your wife hold it out the side window for better efficiency. ON my 2005, the fluid is always cool, even after expressway driving for hours using the cooler that is part of the AC condenser. I can't imagine even needing an auxiliary. But if it were me, I would do a test haul and pull the stick out and see how hot the fluid is. If you can comfortably hold it in your fingers, forget about it.
 
#18 ·
Already have a tranny cooler?

Ok, so I had the van in today to fix a problem with one of the back brakes and next to my brake shop there is a trans shop. I had the trans guy go next door and check out my stuff to see how much it would be to add the cooler and he said I already have an aux cooler for the trans. It is mounted in front of the radiator and has only the 2 trans lines into it. The radiator hoses go into the unit directly behind(towards the engine) this cooler.

As far as I know, this van is not set up with a towing package(from the lack of hitch and 'normal' shocks in back), but what are the chances that I got a 2001 GC Sport with an external trans cooler right off the line? If this was part of some not quite towing package, but something above the basic package, any idea if this cooler is good enough to tow with or does it still need to be replaced for a giganto one?

On a related note, I see a bunch of you referring to the temp your trans fluids operate at. How are you finding this out (other than just touching the dipstick and seeing if it is boiling or not)? I'd be game to add an additional gauge to the dash for trans fluid temp, but where would you run it to? If I had that I'd just add the hitch and see how the unit I have does and change it if neeeded after the first moderate towing I do.

Thanks in advance,
Bill

EDIT I guess my confusion is furthered by 'thebrakeman's post above regarding 2 of the 3 cooling ways being decent enough for 3800#. I've got #2 apparently, but #2 is what is suggested if you only have #1.
 
#20 ·
Some one here once posted that even though you do not have the "tow package" you may have the "heavy duty" cooling package...
I do, and I have an Oil and Tranny cooler on my 08 GC
 
#21 ·
Dear BMeyer1968,
You can likely tell whether the cooler if factory or aftermarket by looking at the way it is attached. If it uses a plastic round silverdollar size backer that has a long nylon spike that goes through your AC condenser and attaches to a similar plastic button on the back side, assume it is aftermarket. However, if they thing is mounted into its own metal bracket attached to the frame somewhere, it is most likely factory. As to Size, go down to an auto supply house after you have the rough dimensions of your add on cooler, say 6x12" and compare that to the ones on sale. The boxes will tell you if it is a standard or heavy duty. The standard ones are usually about 6" tall and the super ones are about 9" to a foot. But again, I would bypass the radiator one altogether and go straight to your aux. one so that a shredding torque convertor does not do in the transmission one day by clogging and burning up your transmission. I had a new transmission put in once and th guy did not clean out the radiator cooler properly, and in 75 miles there was not a tooth left on the gears and they were blue from heat. Clogged radiator oil cooler. Forget 'em.
 
#22 ·
Ok, I don't have the exact measurement, but the cooler is roughly the same size as the radiator, which looks to be about 14 inches tall and about 26 wide. I do NOT have the quarter size plastic circle with nylon wire going through it, but (funny you should mention that) I checked my brothers 02 T&C and he does have it on his cooler, so I know what you are talking about. I'm going to guess that since you refer to some coolers being 6x12 or so and with some of the sizes I found online were around 8x9 or about, that I have a sufficient size cooler for the job.

I'd still like to know if it is possible to hook up a guage to read the temp on the trans fluid (the trans guy said that the computer has the temp reading...so I'm guessing it is possible) so I can police it for the first few trips out.

Now just to add some heavy duty shocks in back and get that hitch put on...away we go.

Bill
 
#23 ·
Just a couple of notes on heavy hauling, especially in mountains, take it out of overdrive. This is how you keep your torque convertor from destroying itself as it locks on and off under heavy load. Drive (3) will be fine. Also, if they still make them, and you have coil springs on the rear (I don't know your model) there are airbags that you can put inside and fill to your preference that will help keep the rear end up better than air shocks and not nearly so much to replace if you blow them out. I had a lot of friends who lived in trailers moving them weekly and they swore by them.
 
#24 ·
I was just looking at my neighbors truck and he has leaf springs with air bags for loading his camper. Nice set up.
 
#25 ·
Well, I didn't know you could put them on leaf springs, how do they attach?
 
#26 ·
Well with out getting under his truck IMO they just use the u bolts to attach them. Try to google them and I'm sure you will get a picture.:thumb:
 
#27 ·
As to your other question, can you put in a transmission oil temp. unit, yes, you can. If there is no other way to do it, you can splice into the rubber hose, if it needs a liquid connection, and put a T in. They sell them at Autozone, in the catalog, but frankly, an oil temp unit and sender will do the same thing, you don't really want your transmission oil too hot anyway. You can see what kind of fittings they sell for it out of the catalog or drill through the oil pan on the back side where it won't likely get bashed, and use a jam nut, you can get them at Lowes in the parts drawers, to hold it in the pan with appropriate rubber washers between.
 
#28 ·
Mr. Gasket 4470 Transmission Oil Pan Drain Plug. Install this in the rear driver
side corner of the pan. The temp sending unit threads into the drain plug hole.
Nice and clean. Then you can drain the pan easily after that.
I have a Sunpro temp gauge, $26 through Amazon. Thats with the sensor.
I am in the middle of a trip that I have been documenting to give people an idea how my 2005 GC performs towing. I will be posting when we are done.
 
#29 ·
Yea right, in the bottom right hand corner of the pan. Right where it is highly likely to get ripped off on some road hump or other debris. Then you will be singing the blues, probably some where far from home.:jpshakehe But then who am I to give my opinion? I speak from experience, and besides it makes for an oil change and oh I'll change that filter next time, its not to bad. :lol:
 
#30 ·
Funny, I don't remember saying BOTTOM of the pan. Please try and READ the words that are written. It is on the back corner, up towards thebottom of the tranny actually facing rearward. Nothing to hit on a speed bump. No way of ripping it out.
3 years of travelling with it there and no problems. I live in the Great White North and even snowdrifts and ice ruts have not caused a problem.
And as far as changing the filter, this makes it easier by draining a large chunk of fluid before lowering the pan. Making it a cleaner job.


GEEZ.
 
#31 ·
Funny, I don't remember saying BOTTOM of the pan. Please try and READ the words that are written. It is on the back corner, up towards thebottom of the tranny actually facing rearward. Nothing to hit on a speed bump. No way of ripping it out.
3 years of travelling with it there and no problems. I live in the Great White North and even snowdrifts and ice ruts have not caused a problem.

GEEZ.
Oh thanks for that little correction. I get the dunce hat in the corner for 5 minutes. That happens when I am speed reading some times. I will try to do better.:nut:
 
#32 ·
No problem.
Sensor location is always a big subject when it comes to tranny temp. On the line going to the coolers will always be the hottest as that is what is leaving the converter. Others prefer after the coolers on the return line. That will always be the coolest. I prefer the pan because that is the fluid which is about to run through the trans. It will be warmer than the return line because it is mixing with fluid already in the pan. And it will be much cooler than the feed line to the coolers. I find that it gives a truer temp reading. Also, the factory sensor is in the pan area as well.
 
#33 ·
I wish you lots of luck with that and a good journey.:ThumbsUp:
 
#34 ·
You know, with all the concern about temperature, I just want to throw in that a oil pressure monitor might be a better gauge of catastrophic (not long term wear) failure. All the transmissions I have lost came from clogging of the radiator oil cooler (which I why I advocate bypassing them so much). If I had a pressure monitor on the outbound side of the transmission, that would have told me that there was a clog and I could have saved the thing just by backflushing the cooler, and, if needed, replacing the torque convertor instead of the whole shooting match. And these are much easier to install, just a T in the outgoing rubber line. These transmissions get so hot they will burn up in 100 miles if they get clogged, but I am not sure how much of that heat would register in the pan, since there is no oil circulation, that is why they burn up. I am sure there is heat transfer, but I would think that by the time it would spread through the metal down to a sump temp sensor it would be too late anyway. Ideally, you would have both. One for monitoring, the other for catastrophic failure.
Just a thought,
tc
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top