Transmission Cooler Reccomendations

[97ranger4x4]

Hey guys.

I just installed a tranny temp gauge on my 97 ranger. I have the 5R55E Auto. I have noticed that my tranny reads about 180-200 during the day. This is with normal driving around town and freeway. Outside temps are in the low 90's. I would like to get it down to around 170 so when I tow or go up to the mountains I wont put to much strain on my tranny. What is the best cooler you reccommend? How hard are they to install? I am an avid mechanic and feel pretty comfortable installing or fixing things on my truck.

-Keith :)

[Totalled]

The biggest that will fit.

[MAKG]

200 deg or so is ABSOLUTELY NORMAL. It's about the same as your coolant temperature. There are no modifications needed, and 170 deg will be overcooling. Your transmission is cooled through the radiator.

[Will]

http://www.piersdiesel.com/images/ttchart.gif

[BDAB]

http://www.transmissioncenter.net/TransTemp.htm

http://web.archive.org/web/20050304080821/http://www.transmissioncenter.net/FluidChart.jpg

http://www.transmissioncenter.net/1405.jpghttp://www.transmissioncenter.net/tc.gif



and I would mount one of these near the transmission in addition to an auxillary cooler

http://www.transmissioncenter.net/Fan2.jpg

no such thing as over cooling.

[mjonesjr]

http://www.transmissioncenter.net/TransTemp.htm

http://web.archive.org/web/20050304080821/http://www.transmissioncenter.net/FluidChart.jpg

http://www.transmissioncenter.net/1405.jpghttp://www.transmissioncenter.net/tc.gif



and I would mount one of these near the transmission in addition to an auxillary cooler

http://www.transmissioncenter.net/Fan2.jpg

no such thing as over cooling.
^^exactly...espically in a transmission....

that is how i have mine setup, and i am about to add another cooler to it.....

[BDAB]

Let me clarify

If I had one of these

http://www.transmissioncenter.net/Fan2.jpg

in my suburban I might still have a functioning transmission in it

we put one in my Uncle's 94 town and country when the new transmission went in and the new transmission has lasted twice as long as the one we replaced. I just put one in my wifes 99 town and country and I am putting one in the suburban when it gets its new transmission and one is going in the motorhome from hell when I figure out its transmission problem. you cannot over cool an automatic transmission.

[mjonesjr]

all a transmission cooler is is another radiator, just for the transmission and not the engine...

[97ranger4x4]

Let me clarify

If I had one of these

http://www.transmissioncenter.net/Fan2.jpg



Where can i get one of these and how much is it going to cost. Where have you purchased your coolers from?

Thanks for all of your help. BTW my truck has 119k miles.

[warhawk]

200 deg or so is ABSOLUTELY NORMAL. It's about the same as your coolant temperature. There are no modifications needed, and 170 deg will be overcooling. Your transmission is cooled through the radiator.

MAKG is correct, most oils are designed to work most efficently at around 190deg. So like MAKG said 200deg is normal. I think he ment that a tranny cooler isn't nessesary not that you would be overcooling.

A tranny cooler would be a good idea if you tow alot or are really put it to your transmission on a regular basis, but for the ocasional tow job or weekend in the mud or on the trail you would be fine with your stock setup.

[97ranger4x4]

MAKG is correct, most oils are designed to work most efficently at around 190deg. So like MAKG said 200deg is normal. I think he ment that a tranny cooler isn't nessesary not that you would be overcooling.

A tranny cooler would be a good idea if you tow alot or are really put it to your transmission on a regular basis, but for the ocasional tow job or weekend in the mud or on the trail you would be fine with your stock setup.

Well that sounds good to me, money I can spend somewhere else.

Thanks for all your help you guys.


Keith :)

[exbass94]

http://www.piersdiesel.com/images/ttchart.gif
So according to that chart, even with the fluid at cool 175 degrees, an automatic will only last 100k miles? Bullshit. Even my A4LD has 135k on it and has no problems yet. I believe the fluid was only changed once at about 60k and it still looks great, but I'm still gonna change it real soon.

[BDAB]

well there you go you interrupted the cycle by actually maintaining your transmission.

you can get it here for $189 http://www.transmissioncenter.net/4l80e.htm. I am going to stand by my statement that you cannot over cool an automatic transmission, and he did say he spends alot of time in the mountains and plans on towing.

[Mutant Pony]

You can over cool a transmission. You should never eliminate the cooler in the radiator because it is also a fluid heater. Your trans will last longer if you keep the fluid in the fluids viscosity range. It will shift better too.
By the charts above I would say that you want to keep your trans fluid around 170 as much as possible.

[BDAB]

let me qualify that again. you would not be able to over cool your transmission. he plans on working his transmission hard and requires extra cooling and I would never recommend doing away with the cooler in the radiator (summit tech support and I disagree on this point, the recommend using a 24,000 gvw cooler and not running the fluid through the radiator) 165 degrees to 180 degrees is where you want to stay. the fan on the above cooler is set to run the fan around 175 degrees if you buy the relay and use the temp gauge for it.

[Wicked_Sludge]

You can over cool a transmission. You should never eliminate the cooler in the radiator because it is also a fluid heater.

beat me to it. what the stock tranny cooler is designed to do is keep the tranny the same temperature as the engine coolant. your coolant temp is actively controlled via the thermostat, thus your tranny temperature is regulated.

since your stock setup is regulated, having the tranny run at 200* doesnt give you any indication of how much of your cooling capacity is used up. what you should do is hook up your trailer and go for a tow. if your tranny temperature climbs higher then what you experience driving around normally, you know your at or over the limits of your stock system, and are in need of an additional cooler.

i hope that comes out clear :rolleyes:

[almostclueless]

Dang!!!! New website, and I STILL find myself agreeing with sludge sometimes LOL.

[BDAB]

lets try this again smart guys ....... raise your hand if you have ever had transmission fluid puking out the front seal in a bronco 2. this can be caused by a few things like the front seal going bad but most of the time it is caused by the engine over heating inturn cooking the transmission fluid wich inturn makes the engine get hotter. the fluid expands and blows the seal. at this point you might as well plan on replacing the heads (because they are cracked) Therostat (because it stuck closed) and a transmission because at this point the bands and clutches have been cast into the deepest hottest parts of transmission hell. a trans cooler with a fan set to run at 175 degrees could have saved this transmission. $189 is cheap insurance for a transmission that costs around $1200... and I have no Idea what a 5r55e costs but I doubt you can replace it for $189. and auxiliary cooling is race and towing proven to keep the transmission in its happy range.

or in the case of my suburban that the temp gauge was stuck on 180 degrees and nobody noticed. it was raining so steam was coming of the truck anyways. it gave no indication it was hot until the transmission started slipping and by this time it was too late. I was towing a around 8000 pounds (rated for 9000) to ann arbor going about 70 mph and the transmission got hot and and started heating up the engine which further cooked the transmission. so yes, in my opinion you can not have too much cooling capacity for an automatic transmission. the closer it stays to 165 degrees the better it runs. Raptor transmission checks all their product in their own trucks before they are shipped and this cooler is proven on a 4L80E pulling 19,000lbs (wieght of their truck and trailer) and it keeps it cool, period

[Will]

Well, I didn't make that chart, but TCI transmissions has it on their site as well.

The tranny doesn't need help getting warm. It does that just fine. The thing about the radiator's built-in cooler is that it is fluid-fluid, not fluid-air. Put on a pair of soaking wet oven mits and you'll see how much more efficient fluid-fluid is over the dry mit fluid-air in transfering the heat from a casserole to your hands.

It's important to keep the cooling system in your truck up in order to also keep the tranny cool. But the tranny WILL get hotter than the engine and the engine's cooling system won't adjust for it enough so the factory puts an auxillary cooler on.

I do not think that particular lubricant needs to be hot to function. It's also used in hydraulic systems that don't deal with anything like the power that a transmission in a vehicle does. It's in my Bobcat--the mechanical clutches are bathed in it and a little 3gph pump drives a 1,200psi 2-valve system--and trust me, the lines do not get hot--the pump gets warm and it definately needs lubrication--which the fluid at maybe 120*F (the pump body gets much less warm than our waterheaters output) provides. But if the fluid is used to lube+cool something like an automatic tranny that might have a 200hp load slipping 5% in it, that is 10 hp worth of pure waste heat transfered to the fluid and it will easily boil, break down into deposits, harden and destroy seals and lose it's viscosity wiping out clutches and bands.

I will definately agree that you cannot overcool and automatic tranny.

This is from amsoils site. According to them (and they know nothing about it, i'm certain) you should definately shoot for that 175*F.

http://www.performanceoiltechnology.com/atfchrt1.gif

[krugford]

Also keep in mind that if you have the factory tow package (or maybe it's just the FX4s), it came with a seperate air/fluid cooler mounted in front of the radiator/ condenser. I know this because the lines they ran really get in the way when you want to remove the front license plate "bracket" and replace it with a real bumper....

-krug

[Will]

Also keep in mind that if you have the factory tow package (or maybe it's just the FX4s), it came with a seperate air/fluid cooler mounted in front of the radiator/ condenser. I know this because the lines they ran really get in the way when you want to remove the front license plate "bracket" and replace it with a real bumper....

-krug

All RBVs have that auxillary cooler. It's obvious Ford wants the temp below the radiators 195* thermostat setting. The radiator is damn efficient, but it doesn't take the temp down quite far enough.

[krugford]

All the new ones have it? When did they start that? I assumed I was special...

[Will]

All the old ones have it too.

[2manyfords]

IIRC, the factory RBV tranny cooler is down stream from the radiator cooler.

[97ranger4x4]

Okay sounds good. I will defenatly hook up a trailer in the next few days and tow it around and see what I can get the tranny up too. I will also look at getting a tranny cooler with the fan built on. The $189 is a little more than I had in mind. I know it is cheap insurance especially with the miles I am starting to get on the truck. I will see if I can find something that maybe isnt quite as hardcore. All of the towing I will do is with a small 4x6 enclosed trailer with about 600lbs of gear in it or a ski boat (but this would only be a short distance 12mi or so)

[Wicked_Sludge]

if your only talking about 7-800lbs then i would be surprised if the stock cooler wasnt enough. thats a fraction of the 3,000+lbs your truck is likely rated to tow.

if your looking for something a little less extreme then the cooler posted, look for just a bare cooler (without fan). your radiator fan will still move plenty of air to aid cooling and you can always buy a small fan to add on later should you desire.

[Wicked_Sludge]

What? You don't need to heat your radiator.

under normal conditions, the engine coolant warms the tranny fluid...not vica versa.

[Capt Jay]

Ya

[BDAB]

IIRC, the factory RBV tranny cooler is down stream from the radiator cooler.

thats how it works, goes into the radiator cooler and then into the aux. cooler. the above diagram shows the hot fluid going in on the bottom and the cold fluid coming out the top of the of the aux cooler ...... thats backwards, heat rises so you want the cold fluid coming out the bottom.

[MAKG]

Some of these diagrams are making me scratch my head.

Conventional crankcase and gear oils generally work fine up to about 350 degrees, not at all coincidentally the peak engine temperature inside crankshaft bearings. ATF is a different lubricant, but it's still an oil and I find it rather hard to stomache that it's so much worse. I think Amsoil is exaggerating. They certainly have a vested interest in doing so. Perhaps a neutral analysis such as from API might be more believable.

As for the transmission temperature charts, there clearly has to be a minimum safe temperature, even if it's nothing more than the pour point of the lubricant (though I'd expect the first problem one would see would be sticky valves in the valve body -- they are steel valves in an aluminum body and will fit tighter when the lubricant is cooler). It's also more than a little weird that the factory would require inappropriate fluid for the operating temperatures.

As for it not being possible to overcool, perhaps that might be true in the summer (though I don't really believe it), it absolutely is possible in extreme cold. Given that you can drive to the Arctic in winter, it can't be ruled out for everyone. It's like saying you don't need antifreeze.

[mjonesjr]

All the old ones have it too.
no they don't.....my '97 had no such aux cooler....it just had the one in the radiator.....and mine has the tow package....

everything else you posted Will i agree with 110%......you can't over cool a tranny.....espically an automatic....

i am in the process of installing a second aux tranny cooler on mine....
as of this coming Saturday mine will look like this:
Tranny-->Radiator-->Aux Cooler #1-->Aux Cooler #2-->Tranny.....

IF by chance the radiator has a t-stat in it so it wont flow tranny fluid until it gets to a certain temp, then it will hold the fluid in the radiator until it reaches that temp.......THEN it will take that 190* fluid and pass it throught the 2 aux coolers before hitting the tranny, thus cooling it back down to less than 190*........

also, IF you have a tranny temp gauge, you really need to put the sensor in the tranny port on the side.....there is a little 1/8" NPT plug just behind the shifter linkage (i know for sure on 5R55E's, but not on other transmissions) that is used for testing the main pump pressure. You install the 1/8" NPT sensor in place of this plug, then run your sensing wire from the gauge to the sensor.....and bada boom you are reading ACTUAL tranny temperature, not fluid temperature..........

[Will]

It's very thin lubricant. The minimum safe temperature appears to be below freezing. And it's not inappropriate for the operating temperatures. Amsoil is of course bending it for their own benefit, but they indicate the red area is borderline, not outside of its operating range.

But I wasn't too worried about that part of it. Clearly, ambient temperature in within it's operating range. And since the vehicle is unlikely to actually cool the fluid below ambient, I think it's very safe to say that overcooling is impossible. Maybe the real danger of putting too much garbage in the lines is restricting the flow too much. I would replace the factory aux. cooler and put in one of those fancy fan ones with a thermostat switch for the fan.

[MAKG]

There isn't a single transmission temperature. You always measure the fluid temperature. The important variable is that the sensor be immersed in flowing fluid.

The hottest spot is probably inside a clutch pack, the torque converter, or the oil pump, depending on what the transmission is doing at the time. None of those are good places for a temperature probe. As a replacement, I'd suggest putting the probe at the transmission outlet port (on the way to the radiator/cooler) if you want to monitor internal transmission temperature, or on the OTHER line if you want to monitor the cooling circuit. Note that these will yield very different results.

Note that those temperature diagrams don't say where the temperature is to be measured....but they suggest it's the cooler output. That's the coldest spot.

Will, there is a difference between continuous operation at ambient, and a warm-up cycle. Certainly, you won't blow up the transmission from a few minutes operation at ambient in a normal climate. But it's far from clear that continuously operating the transmission there is a good thing. A transmission has to be vented somehow, so there is a small amount of water vapor that gets in through the vent. Continuous operation below the boiling point (everywhere in the transmission) may allow some accumulation. It can't be anywhere near as bad as for crankcase oil, since there is no combustion.

[oldmantruck]

you should be able to find a cooler on ebay in the 30- 50 buck range( including shipping) there are also 10 inch fans on there for about the same if you get the relay and thermistatat, so you should be able to piece together the electric fan type cooler for about 75 bucks rather than spend $185. might just take a little more tinkering.

[97ranger4x4]

Sounds good guys. BTW my temp gauge is on the bottom of my transmission pan and submerged in the fluid. I will check ebay and some other places for tranny coolers with fans.

[mjonesjr]

There isn't a single transmission temperature. You always measure the fluid temperature. The important variable is that the sensor be immersed in flowing fluid.
no.....really? The transmission temperature sensor being placed in the 1/8" NPT plug hole will have fluid running over it.....try and take that plug out with out spilling fluid......the sensor is the EXACT same sensor that is sent with the water temperature gauges.....putting the sensor IN the tranny itself gives you an acurate reading on what temperature the tranny is running at, not what the fluid temp is inside the line....just like the engine temp is recorded INSIDE the engine, not the radiator hoses...

I'd suggest putting the probe at the transmission outlet port (on the way to the radiator/cooler) if you want to monitor internal transmission temperature, or on the OTHER line if you want to monitor the cooling circuit. Note that these will yield very different results.
and the outlet port location will show roughly a 20* LOWER temperature than the spot that i suggested putting the sensor......so if the sensor is at the outlet on the tranny line, then you are NOT getting an acurate reading.....when i had my sensor in the tranny line by the radiator, i was reading a 20* LOWER temperature than were i have it now......tranny temperature should be read just like an engine temperature is read, from INSIDE the tranny, not were it is cooled....

Note that those temperature diagrams don't say where the temperature is to be measured....but they suggest it's the cooler output. That's the coldest spot.
yes that is the coolest spot, but why would you want to measure the coolest spot? your engine temperature isn't measured at the radiator, it is measured were it picks up its heat, the engine.......why would you want to read the tranny temp after the cooler? that isn't the most accurate spot since the fluid will heat back up after it enters the tranny......you should read the temperatures from INSIDE the tranny itself.....

[MAKG]

mjones, you're confusing pressure with flow. Try the following thought experiment:

Put a foot long extension on your oil pressure sender, and put a temperature probe in it. If you remove the probe and run the engine, you'll get oil everywhere. But there is no flow with the probe installed.

That you will spill fluid out means there is pressure. Not surprising at all on a pressure port... and whether the probe is in flowing fluid depends on the geometry of the port. It's not hard to imagine it being longer than the probe.

There are a few reasons you might want to put a probe at the cooler outlet. Most importantly, if you are going to rely on a graph to draw conclusions you MUST match its assumptions or you'll simply be wrong. Another reason is to measure the effectiveness of temperature regulation -- and in particular if the cooler is big enough (which was after all the question at hand). But it's not an appropriate place for measuring transmission temperature.

Accuracy depends on what you are doing with your gauge. You're fooling yourself if you think pump temperatures are the only variables. What you would really like to know is the temperature at the seals and clutches. So, why do you think the pump is a better analog than the transmission fluid output (NOT the cooler input -- there are several feet of substantially cooled line in between)?

[mjonesjr]

the sensor does have flowing fluid over it. The pump port shows a higher temp than what it shows in the line. I have had my sensor in BOTH locations, and speaking from experience, the pump port is a more accurate tranny temp reading than that of in the line by the radiator......

[MAKG]

Please answer the question. Why do you think that the pump pressure port temperature is more accurate than the transmission fluid output? "From experience" is vague and unverifiable, and please don't confuse the two ends of the cooler line.

[mjonesjr]

i did answer, can you read?

here let me waste my time and answer it again for you:
because it is inside the tranny itself. Speaking from experience, the sensor inside the tranny itself shows a higher reading that in the line; roughly 20* higher. By the time the tranny fluid has reached the cooler, it has already cooled down from what the actual interior temperature of the tranny is.



OMG i forgot you are the technical advisor, you know all....

[MAKG]

That's a higher reading. Not a better reading.

You're assuming they are the same.

As I said earlier, what you would like to know is the temperature at the seals and the various clutch packs, but that's not easy.

It is not at all obvious that the pump temperature is more closely related to those than the output temperature.

[Will]

Excuse this long paste, but it's worth reading...it's from HERE (http://www.700r4.com/faq/whatlock.shtml)

ADDITIONAL OBSERVATIONS AND RECOMMENDATIONS


If you are going to use a high stall converter, tow, haul heavy loads, have a lifted vehicle with big tires, etc, we strongly recommend installing a temperature gauge to monitor the fluid temperature inside the transmissions pan. The fluid in the pan is primarily fluid that has just returned to the transmission after passing through the heat exchanger located inside the vehicles radiator. Locating the temperature gauge sender in the transmissions pan will tell you whether your vehicles temperature control system can handle the temperature management properly. We have installed and monitored all vehicles that have been through our shop over the last eight years and consistantly see 140 to 160 degree F in the pan when the factory cooling system is working correctly. As an observation; the temperature between what you see on the engines temperature gauge and the fluid temperature inside the transmissions pan should always maintain a 30 to 50 degree F spread! Always!

Remember, the temperature you observe on the gauge is telling you the fluid temperature after it's been cycled through the radiator heat exchanger! This reading has nothing to do with how hot the fluid got inside the torque converter. If it reached 300 degrees F inside the torque converter and you only see 150 degrees F at the sensor in the pan, it doesn't mean the fluid wasn't overheated and degraded! We do not know of a reasonable way to monitor the fluid temperature inside the converter, so we always assume it is very high during hard work situations. Locking the converter during high heat production situations is the only way to prevent the overheating from occuring in the first place!

The manufacturers of Dextron III transmission fluid have told us that a continuous steady 150 to 160 degrees will yield maximum longevity for the fluid. This is not possible because of the various driving situations you subject the fluid to so proper management of the torque converer clutch is the only reasonable way we have found to eliminate fluid degradation from overheating. I'm sure most of you have seen the charts that show the rapid destruction of transmission fluid properties as operating temperature increases. Most charts show a 50% loss of fluid life for every 15 degrees of operating temperature increase above their designed ideal operating temperature, normally 165 degrees F. This is the reason we recommend each fluid cycle start at 150 degree F. or less.

We also recommend a complete annual flush of the transmission fluid. We have a very simple method we teach our customers so they can change the whole systems volume not just the 4 1/2 to 5 quarts you can change by draining the pan.

[MAKG]

That explains a few things. Especially why 200 deg is listed as "bad" for ATF. It's not actually measuring anything meant to resemble peak temperature, but is instead looking at cooling capacity.

SOME heat is lost through the pan as well (by conduction).

[97ranger4x4]

How do you flush your entire transmission. I have always just dropped the pan and changed the filter.

[Wicked_Sludge]

the easiest way is with a fluid exchanger (in other words, have a shop do it). theres also a procedure that involves removing the cooler line, but i wouldnt reccomend it for novices as its easy to ruin a tranny if not performed properly.

[97ranger4x4]

the easiest way is with a fluid exchanger (in other words, have a shop do it). theres also a procedure that involves removing the cooler line, but i wouldnt reccomend it for novices as its easy to ruin a tranny if not performed properly.

Well in that case i will not be performing this. How much does it usually cost a shop to do it?

[Wicked_Sludge]

depends on your area. your best bet is to just call some shops in your area and ask. they can give you prices over the phone.

[arrabil]

Jiffy Lube does it. Can't be too much since they need to move you quickly to make money.

[Sasquatch_Ryda]

we charge 129 canadian for a transmission flush with regular old mercon (specialty fluids extra mercon V, mercon VI) at the dealership i work at

[Will]

no they don't.....my '97 had no such aux cooler....it just had the one in the radiator.....and mine has the tow package....
It was a standard part of the tranny at least through '91--I have the complete service manuals for '89 and '91. I suppose they increased the capacity of the built-in cooler sometimne before '97. Thanks for the correction.

[arrabil]

My '96 Ranger doesn't have one either. They probably thought they fixed the problems in the A4LD with the 4R/5R series. Fools.