Aftermarket Transmission Cooler

[Fifty150]

[Double Nickels]

On 6/14/2019 at 7:02 AM, DanDweller said:

  they also didn't recommend a power flush--Is that the same as the fluid exchanger 

 

Not the same. They are referring to a pressurized machine.  Dealership and better shops use a machine without a pump or pressure.

 

 

On 6/14/2019 at 7:02 AM, DanDweller said:

 

On the cooler, in that other thread there were comments about the tranny fluid being controlled by a thermostat.  I worry that adding an aftermarket cooler (no bypassing) could end up keeping the fluid temperature too low.  Is that worry unfounded?

 

 

 

Your van has an thermostatic bypass valve.  Until the fluid reaches operating temperature, it bypasses the cooling system.  

[Fifty150]

On 6/14/2019 at 8:38 AM, Beta Don said:

There are half a dozen different Transmax fluids, but if you buy the one that says "Ford Approved for Marcon LV applications" on the label, you've got the correct one. 

 

 

Don, thanks for pointing that out.  Real easy to make that mistake.  Especially with their High Mileage, Domestic Vehicle, Import Vehicle......the list goes on. And they are all branded as Transmax.

Edited June 18, 2019 by Fifty150

[DanDweller]

23 hours ago, Fifty150 said:

 

 

The transmission fill amount is 4 liters.  We don't use the metric system, and it is confusing.  You can do this with 12 quarts.

 

 

For your final fill, after you add 4 quarts, or 1 gallon, you will add 7.256 ounces.  That will be 4 liters.  

 

How you do it is up to you.  I used a measuring cup (stolen from ex-girlfriend's baking supplies).  Buy an extra quart, and use 7 - 8 ounces from that.  Pour out 7 - 8 ounces of the first quart you open, and set that aside for the final fill.  Or, take an ounce from each of the 1st 8 quarts you open.  If you get between 7 and 8 ounces, you will be fine.  You will not be overfilled or underfilled by less than 1 ounce.

 

Look around a little bit before you order the fluid.  There are alternatives to Ford Motorcraft LV.  Walmart now sells a Supertech LV.  Mag1 offers LV.  When I serviced my transmission, I used Valvoline MaxLife which is labeled for LV.  Another forum member used Triax Global ATF.  You always hear that you should only use Ford Motorcraft Mercon.  Motorcraft LV is what your transmission was engineered to use.  Other people have found that other fluids work also.

 

 

 

 

 

 

 

 

Thanks again for helping me understand!  I just went ahead and ordered the 12-pack through Amazon.  Rockauto.com seems to have the best price until you get to paying for shipping, and then it comes to the same cost as Amazon.  But then they also impose a tax even though my state doesn't require one (there was an IRS-style interrogation-gauntlet I started to go through to be deemed "exempt from the tax, but it quickly gave me a headache as I don't know the answers to some of the questions and usually only handle one research rabbit hole at a time--the current one being the transmission-gauntlet).  

[DanDweller]

4 hours ago, Double Nickels said:

 

Not the same. They are referring to a pressurized machine.  Dealership and better shops use a machine without a pump or pressure.

 

 

 

 

Your van has an thermostatic bypass valve.  Until the fluid reaches operating temperature, it bypasses the cooling system.  

Thanks for clarifying.

[Fifty150]

3 hours ago, DanDweller said:

  Rockauto.com seems to have the best price until you get to paying for shipping

 

It's difficult at best, to negotiate through the process of buying.  We all want the best "out the door" pricing.  Sometimes, that can be found locally.  My local O'Reilly's will price match against direct competitors.  When Amazon has a low price, Home Depot & Walmart usually has a similar price.  I go to O'Reilly's, and they will match Walmart or Home Depot's price.  

 

[Fifty150]

Okay, I think I've got it.  

 

Part No. 7A035 is the transmission cooler.  It is an oil to water cooler which uses coolant to bring down the transmission fluid temperature.

 

The line which goes back towards the front of the transmission is the return line.  Fluid has either bypassed the cooler, or is returning already cooled, to the transmission.   

 

The shorter connection at the rear of the transmission is the fluid cooling line. Hot fluid flows out from this line, to Part No. 7H322, the cooler bypass valve.

 

It looks like the parts are already available from Ford, as there are other cars which come with a factory tow package which includes auxiliary cooling.  It looks like everything could fit.

 

Edited June 23, 2019 by Fifty150

[G B L]

The fact that the cooler operation is controlled means that the fluid will operate at about the  same temp most of the time.

I pull this trailer a lot  it weighs 1400-1600 LBS most of the time I tow it.  When I have the transmission temp on the scanner it does not raise the fluid temp much so I think the cooler in the Radiator is adequate for most of the trailer towing.

[Fifty150]

5 hours ago, G B L said:

The fact that the cooler operation is controlled means that the fluid will operate at about the  same temp most of the time.

 

 

The thermostatic bypass valve is in the open position, which allows fluid to bypass the cooler and return to the transmission.  When a preset temperature is reached, the valve closes, and fluid will flow to the cooler.  It's like the radiator thermostat, except that it closes instead of opening.  The vehicle's computer needs the engine and transmission to reach operating temperature, before it operates at efficiency.  In an ideal situation, your car is not overloaded, you are not climbing hills, and the ambient air temperature under 100 degrees Fahrenheit. 

 

The little oil to water heat exchanger bolted on top the transmission allows cooled radiator fluid to bring down the transmission fluid temperature.  I have heard that operating transmission fluid temperature can be acceptable anywhere between 185 - 220, in modern vehicles.  The car is designed, with a bypass valve, so that the vehicle can warm up, and not "over-cool".  In the event that the transmission temperature is overheating, your only alternative is to pull the vehicle over, leave the engine running, raise the hood, and wait for the transmission fluid to cycle and cool. 

 

Ideally, you should not need any added cooling for normal driving.  If operating in extreme conditions, the cooler may be beneficial.  All day, stop & go, extensive idling, in hot climates.  Some people overload without knowing.  If you have 7 people, plus all of their stuff, a rooftop carrier, and a small trailer - like you're going  to a campground on a holiday weekend, everyone drives a little slower in the campground, uneven terrain, dirt roads with a little wheel slip, maybe a very small boat on a trailer......  I can imagine wanting a little more transmission cooling.  

 

Of course, I'm from the mindset of driving trucks & Jeeps.  Stupid to think that trucks & Jeeps, which you think are engineered to go offroad, all need transmission coolers because the transmission fluid temperatures soar when you go offroad.  I have no worries at all about the family loading into the van for a trip to dinner & a movie.  Even a long road trip, where it's mostly freeway driving with the torque converter locked, should be fine for 12 hour drives.  But the auxiliary cooler can't harm the transmission in any way.  

Edited June 23, 2019 by Fifty150

[G B L]

An auxiliary cooler  will help at the extreme .  I will have to find out what the temp setting is for the cooler is.

The  temp of the fluid for the Tc is 20 degrees higher than the L 480-E in my other van, and the drain color after 25000 miles shows it. Cooler is better over time.

 

[Fifty150]

The bypass valve should be set for 185.  Fluid exiting from torque converter must reach 185 before the valve closes and fluid flows to cooler.  Temp seen by sensor is lower than temperature of hot fluid in cooling line.  

[G B L]

Good info, but 185 will definitely shorten the life of the fluid.

[Fifty150]

If 185 worries you.......

 

Consider that the temperature sensor is usually located in the valve body to measure an average "pan temperature".  Same area in other transmissions where there is a transmission pan, with a test port right above the pan bolts.  This means that the torque converter temperature is a lot higher.  Fluid exiting at the cooling lines is significantly higher than what you see as a temperature reading from the car's computer.  That hot fluid travels through the cooling system, and is returned to the sump.  Theory being returned fluid at the bottom of the pan is cool, mixing with hot fluid already in the transmission, and there you have your average temperature or pan temperature.  

 

Although transmission experts advise against it, some people simply remove the bypass valve.  This forces fluid to always pump through the cooling system.  It takes a little bit longer for the fluid to heat up.  But it does nothing to create additional cooling.  Additional cooling can only be achieved by adding a cooler, and perhaps a cooler with an electric fan.  

 

My experience is that the coolers with the fans work best.

[Fifty150]

On 6/13/2019 at 6:59 AM, DanDweller said:

 

2)  Is there a chance that resetting the adaptive learning codes will make a difference?  (A guy who could have charged me $140 to do it advised against it because he said it will learn all on its own anyway, with the new fluid and my driving.)

 

 

 

You can download Forscan, and clear the adaptive learning table yourself.  It's the first option that comes up with the little wrench icon.  Don't pay that guy $140 for clicking on a mouse.  If you really want to spend the money, pay one of the guys here on this forum to come over and do it for you.

 

 

 

Edited June 24, 2019 by Fifty150

[Double Nickels]

On 6/17/2019 at 5:23 PM, DanDweller said:

Ok, so I'm about to order the Mercon LV on Amazon and I see they come in 12 quart boxes. 

 

 

How did it go? Did you exchange the ATF?

 

It may also be a good idea to monitor the ART temperature.

 

 

[stanger_missle]

I'm glad I found this thread since I'm dealing with high trans temps in my TC. My TC is a 2015 2.5L with 109k miles. I do not know the service history. I was tooling around a few days ago with Forscan on my phone and I noticed the trans fluid temp was over 200°F while cruising at 75mph on a flat interstate (it is Florida after all). It was about 95°F ambient air temp and I had the A/C running. Coolant temp was about 195°F. I got off the freeway and stopped at a fast food drive thru. They were backed up so it took about 20 minutes to get my food. I noticed the trans fluid temp was creeping up. All the way to 230°F! After I finally got my food, I took a 45mph road for about 3 miles to my house. The trans fluid temp went down to 208°F while moving but crept up to 210°F while stopped at stoplights.

 

The engine undertray is gone. It fell victim to an errant tire tread in the road (Florida road gator). After that happened, I was crawling under the front to check for damage and I noticed the infamous left side axle seal leak. Its just seeping but the whole underside of the transmission is covered in fluid. So I know the fluid level was below where it should be.

 

Today, I went to the auto hobby shop to drain and refill the transmission. I have a case of Mercon LV that I bought from Rockauto. With shipping factored in, it was still almost $3 a quart cheaper than I could get it for locally. Here is what the fluid looked like:

        

 

Not terrible but still pretty dark. There was still a hint of red in it. It did not smell burnt. I filled the transmission back up using the method outlined in the factory service manual.  On the way back to my house, I took the same freeway and 45mph road as before. The trans fluid temp hit 205°F. Ambient and coolant temps were within 3°F of the previous readings. I still need to do 2 more drain and refills on the transmission. I also have another engine undertray and lower bumper tray on order. I'm still worried that the temp is indicative that something else might be wrong. The 2-3 upshift is a little jerky at times and I swear I'm noticing some slippage or shift flaring in 3rd. I don't know if the valve body is leaking or the clutches are worn. I did order a Sonnax ZIP kit just in case. Its a lot cheaper than a new valve body ($$$) or a reman transmission ($$$$).

 

 Things that have crossed my mind:

- valve body bores are worn and leaking causing poor shift quality and slippage which is contributing to the high fluid temps.

- clutches are worn from poor maintenance from the prior owner(s). Not much to do about this other than a rebuild/reman.

- oil to water heat exchanger is clogged with clutch material. The part (Ford part # CV6Z7A095A) is only about $60. If I pull it off to inspect, I'm just going to replace it.

- axle seal leak caused low fluid level which coupled with poor maintenance by the previous owner(s) means the transmission is hurt and on borrowed time.

 

Its making me nervous to drive the van on my 55 mile daily commute. Something is going on but I don't know exactly what it is.

 

[Fifty150]

It would have been interesting to collect the drained ATF.  You could have measured it to see how much came out.  That would have given you an idea of if the transmission fluid was low, and how much it was low.  You could have also sent in a sample for used oil analysis.  

 

Get that axle seal replaced.  You don't want to keep losing ATF.

 

 

4 hours ago, stanger_missle said:

I noticed the trans fluid temp was over 200°F

Consider that the OEM thermostat opens at 190.  That transmission cooler bypass valve probably closes at 190.  Transmission operating at over 200 is nothing to be concerned about.  You should be able to operate up to around 225 without concern.  Other users see temperatures over 200:

 

 

Up to 250, I would be concerned.  From what you describe:

 

4 hours ago, stanger_missle said:

it took about 20 minutes to get my food. I noticed the trans fluid temp was creeping up. All the way to 230°F!

1st of all, Popeye's is out of those chicken sandwiches nationwide.  So forget about it.  You are only wasting your time sitting in a drive through line.  

 

With the car in "d", and you are standing on the brakes, the torque converter is still spinning and heating up the fluid.  If you have to sit in traffic, or a drive through line, it's better to be in "p" or "n".  But even then, the temps should have been maintained by the cooling system.  Your AC was on.  The electric fan was on.  The coolant should have been much lower, and reducing the ATF temps via the heat exchanger.  

4 hours ago, stanger_missle said:

- oil to water heat exchanger is clogged with clutch material. The part (Ford part # CV6Z7A095A) is only about $60. If I pull it off to inspect, I'm just going to replace it.

Coolers clog.  So do transmission lines.  Another item is the cooler bypass valve, which also can clog, and prevent the valve from closing.  A simple device.  When open, the path of least resistance is gravity bringing fluid back down the return line to the transmission.  Valve closes, and fluid now has to follow the line to the heat exchanger.  Service manuals instruct technicians to flush, and backflush the cooling & return lines, the bypass valve, and heat exchanger.  You can decide to to all of that.  And whichever parts do not, or cannot, be flushed clean, you can replace.  Or as you pointed out, once you take it off, you may as well install a new unit.  This will ensure that you do not have any blockage, anywhere in the cooling system.  

 

 

 

 

[Fifty150]

7 hours ago, stanger_missle said:

Mercon LV that I bought from Rockauto. With shipping factored in, it was still almost $3 a quart cheaper than I could get it for locally

The least expensive ATF, which appears to work without issue, is probably Valvoline Maxlife, by the gallon, from WalMart.  But I have seen where Mercon LV is available in 6 gallon boxes, which seems like the best option for those planning to service the transmission correctly, and on a regular basis.  Another forum member is using Triax fluid.  His van is running.  He has not reported any problems with that fluid.  I have seen other brands of low viscosity fluid.  Phillips 66, Mag 1, Supertech, Castrol.....so there are other options.  You do not have to feel like Mercon is the only game in town.  

 

 

7 hours ago, stanger_missle said:

still need to do 2 more drain and refills on the transmission

I thought that you are suppose to perform the triple drain & fill all at once.  Not drain & fill, drive around for how ever many weeks, then do it again.  You should probably address all of your other issues first.  Maybe clear the adaptive learning tables to see if the transmission will relearn and shift smoothly.  Fix the axle seal.  Clean out your cooling system.  Then perform the 3X drain & fill.

 

7 hours ago, stanger_missle said:

Not terrible but still pretty dark. There was still a hint of red in it. It did not smell burnt.

It doesn't look good.  But that is to be expected.  No used fluid coming out looks good.  I would be shocked if you had 100,000 miles, and clean, red fluid came out.

 

 

 

 

 

 

 

[Beta Don]

8 hours ago, Fifty150 said:

The least expensive ATF, which appears to work without issue, is probably Valvoline Maxlife, by the gallon, from WalMart.

 

I'm using Castrol Transmax Full Synthetic Multi-Vehicle that I bought online from Advance Auto Parts for $5 a quart, with free shipping on orders of $50 or more.  There are several different Transmax fluids, so make sure you get the one that says "Ford Approved for Mercon LV Applications" on the front of the label.  I'm still not sure if Mercon LV is 100% synthetic or not, but I wanted a full synthetic which wasn't ridiculously priced, so that eliminated Mercon LV from consideration  -  I hate paying 2X or 3X for the same stuff others sell for a reasonable price.  Mercedes is the same way for ATF for the trans for my Sprinter chassis motor home  -  You gotta search high and low for a 'non-Mercedes' fluid that meets their specs . . . . but it's out there if you look hard enough and you can save a small fortune if you're a believer in regular fluid changes

 

Don

[Eddy Kilowatt]

16 hours ago, stanger_missle said:

 Things that have crossed my mind:

- valve body bores are worn and leaking causing poor shift quality and slippage which is contributing to the high fluid temps.

- clutches are worn from poor maintenance from the prior owner(s). Not much to do about this other than a rebuild/reman.

- oil to water heat exchanger is clogged with clutch material. The part (Ford part # CV6Z7A095A) is only about $60. If I pull it off to inspect, I'm just going to replace it.

 

Consensus of my online reading is that the 6F35 puts a lot of wear products into the fluid, which gunks up and/or wears out the valve bores, causing poor shifts and eventually burned clutches.

 

A major source of wear products is the torque converter clutch (TCC).  It's apparently a carbon material (would explain the black fluid we see) which is durable enough that Ford programmed it for continuous slip under some operating conditions ( https://www.sonnax.com/tech_resources/254-a-slippery-slope-the-what-and-why-of-woven-carbon-friction-material ).  There's a PCM parameter for TCC slip that you can see with ForScan, TCC_Slip_Rat or something like that... sure enough if you watch it you'll see it slipping at a steady 20 rpm rate around 14-1500 RPM in 4th, 5th, and 6th, and slipping briefly during throttle transitions.  (At least, my newly-rebuilt unit does this... I presume it's deliberate.)

 

Based on the nasty black fluid everyone sees,  I myself am leaning toward trying to fit an external filter, rather than an additional cooler.  There are a bunch of filters on the market, popular with the trailer towing crowd ( http://www.trailerlife.com/tech/diy/tranny-filter-tech/  ), though I haven't found a direct 6F35 application and am just at the beginning of figuring out how you'd plumb it in (and whether the pressure drop would mess up tranny operation).

 

But if you're seeing 230F on the regular then that seems excessive to me, so I might be looking at the fluid cooling too.   The fluid cooling system seems pretty elaborate, at least per the shop manual... there's the fluid-to-water heat exchanger, the fluid cooler bypass valve, and (apparently) two PCM-controlled coolant valves, one sends hot coolant to warm up the fluid, the other sends cool coolant to cool off the fluid (!).   Plenty of things to break.  Any way to get a couple of temperature sensors on any of the coolant or fluid lines, to verify how the system is operating?  Also, what's your engine coolant temperature when this 230 is happening... it might well be 210, and a 20 degree drop is the best the little factory cooler can do.

 

 

 

[Double Nickels]

Part 3, return line from part 1 heat exchanger to part 2 bypass valve, is the best location to splice for auxiliary cooler.  This allows the OEM system to cool fluid first.  Then the auxiliary unit will provide additional oil to air cooling.  If the transmission is not warm enough, the bypass valve will send fluid back via the return line.

 

 

Green cooling line where fluid comes out the front of transmission is the best location to tap for a filter.  It will trap particulate matter before it can clog the other lines, bypass valve, heat exchanger, and cooler.

 

[Beta Don]

I think adding extra trans cooling to a modern vehicle is more complicated than it was in the old days.  The ECU wants to control the trans temp and too cool is probably almost as bad as too hot.  If you add cooling in a way that the ECU can't warm up the trans quickly on a winter day, you'd probably be doing more harm than good . . . . at least in my opinion

 

Don

[Fifty150]

Adding a cooler to any modern vehicle isn't more difficult or complicated.  You still have to find a suitable location for your cooler, drill holes, and mount.  The return line still needs to be spliced.  You still have to route the new transmission lines in a way that it doesn't interfere with anything else or get caught in a moving part.

 

The cooler bypass valve will prevent ATF from going to the cooling system until the transmission reaches the appropriate temperature regulated by the bypass valve.  Any extra coolers added inline after the OEM heat exchanger will not effect the transmission warming up.  Essentially, the ATF will warm up to 190 F before the bypass valve closes, and fluid flows through the cooling system.  If the cooling system, with an extra cooler, reduces the ATF to under 190, the valve will open again, allowing the ATF to simply bypass the cooler.  I don't think you can "overcool" the transmission.  No chance that an auxiliary cooler can drop your transmission operating temperature to an unacceptable level.

[Beta Don]

15 hours ago, Fifty150 said:

Adding a cooler to any modern vehicle isn't more difficult or complicated.  You still have to find a suitable location for your cooler, drill holes, and mount.  The return line still needs to be spliced.  You still have to route the new transmission lines in a way that it doesn't interfere with anything else or get caught in a moving part.

 

The cooler bypass valve will prevent ATF from going to the cooling system until the transmission reaches the appropriate temperature regulated by the bypass valve.  Any extra coolers added inline after the OEM heat exchanger will not effect the transmission warming up.  Essentially, the ATF will warm up to 190 F before the bypass valve closes, and fluid flows through the cooling system.  If the cooling system, with an extra cooler, reduces the ATF to under 190, the valve will open again, allowing the ATF to simply bypass the cooler.  I don't think you can "overcool" the transmission.  No chance that an auxiliary cooler can drop your transmission operating temperature to an unacceptable level.

 

Well, our resident 'expert' has spoken!!  -  Modify away!

 

Don

[Eddy Kilowatt]

18 hours ago, Fifty150 said:

  Any extra coolers added inline after the OEM heat exchanger will not effect the transmission warming up. 

 

The trans is not the only source of heat in the system.

 

According to the shop manual (303-03B, Engine Cooling), the TCs have a coolant valve that is specifically called the "transmission heater coolant control valve" (item 24 in the Engine Cooling diagram above), whose job is to direct hot coolant to the transmission heat exchanger for the purpose of speeding the warmup of the trans fluid.      Ford seems to have a temperature they want that trans fluid to be at, and they seem to want it to get to that temp faster than just letting the trans warm the fluid up.  

 

I haven't dove into it far enough to figure out how that plays with the "transmission cooler bypass valve" on the fluid side of the heat exchanger, but anyone contemplating mods would probably do well to understand how the whole system is supposed to work -- both heating and cooling the trans fluid -- before adding additional cooling.