351 Rear main seal while trans is out anyway?
#16
07-08-2015, 06:50 AM
I get your point and can't really understand or explain why 
requires TWO coolers----is that specifically specified, two in addition to the radiator cooler? Seems odd to me is all............
Despite the ID of the cooling tubes the length of the additional path as well as all the turns and bends would be the additional restriction I mention.
FWIW Mark has a reply about all this relating to cooling and why the radiator-first design has a purpose and reason. I'll find that reply and either link the thread or excerpt and post his thoughts here.
FWIW I'm about to do Mark's trans flush and in preparing have noticed my '03 E250 w/5.4 has what seems to be a factory-type second cooler, the fluid flow being radiator first then to the second cooler before being returned to the trans. Not sure if the trans was replaced before me buying that van, if was factory original or added by the PO. No other E250's I've owned--all '97 and later---have had that second cooler.
Link: https://www.ford-trucks.com/forums/1...ice-versa.html
Excerpt:
Mark replied to this question:
requires TWO coolers----is that specifically specified, two in addition to the radiator cooler? Seems odd to me is all............Despite the ID of the cooling tubes the length of the additional path as well as all the turns and bends would be the additional restriction I mention.
FWIW Mark has a reply about all this relating to cooling and why the radiator-first design has a purpose and reason. I'll find that reply and either link the thread or excerpt and post his thoughts here.
FWIW I'm about to do Mark's trans flush and in preparing have noticed my '03 E250 w/5.4 has what seems to be a
factory-type second cooler, the fluid flow being radiator first then to the second cooler before being returned to the trans. Not sure if the trans was replaced before me buying that van, if was factory original or added by the PO. No other E250's I've owned--all '97 and later---have had that second cooler.Link: https://www.ford-trucks.com/forums/1...ice-versa.html
Excerpt:
Mark replied to this question:
Not here to start an argument but how is that not more efficient? Radiator temp is hotter than ambient air. A properly sized stand alone cooler will cool the fuild more than a rad cooler. About every transmission builder I have seen does this where a radiator cooler fails. Quite a few heavy haulers around do it as well and report cooler temps than through the stock set up. Only problem I could see is in a really cold climate you could over cool the fuild if that is such a thing being that it doesn't pass through the radiator.
The old fallacies get repeated over and over.
Maybe all of the automakers don't know what they are doing when the spec both a radiator cooler and an air to oil cooler on all vehicles that tow.
The water to oil cooler inside the radiator is much more efficient at removing heat from the ATF than the largest air to oil cooler you can mount in a pickup. The water to oil heat transfer is MUCH more than you can get with air to oil.
And the difference in temperature between the radiator coolant and the ambient air? Not as much as you think it is.
The coolant where the ATF is being cooled is in the "cold" side of the radiator. This is the side where the coolant has already passed through the radiator to be cooled. It is not at engine temp, usually not even close.
I've measured extreme temperatures in my capacity as an Automatic Transmission Cooling Engineer at Ford. At VERY cold temperatures, such as -40F, the coolant in the cold side of the radiator didn't rise above about -30F. The coolant going into the radiator was about 200F. The engine thermostat only opens for a very short time before it cools off with -40F coolant coming into the engine. So the coolant in the radiator sits there with -40F air blowing over it. So the ATF goes into the radiator and sees coolant that is not above -30F. Kinda blows the whole heating the ATF myth out of the water, doesn't it? And remember, I measured these temperatures, I'm not just guessing how this works.
And in hot climates we only tested at +95F and above. When I ran trucks (up to the F-550) up 8% grades at max GCVW the temperature drop across the radiator would get down to as little as 15F. The "cold" side of the radiator was still cooler than the ATF. The transmission was also working very hard and generating a ton of heat. The radiator really helped keep the trans temps under control.
And where the radiator cooler really shines is where the air to oil coolers are next to useless is high load reversing. Try backing up a heavy trailer up a grade or on a soft surface. There is little to no airflow over the air to oil cooler so it does very little cooling. The fan clutch in these trucks won't react to transmission temperature, only engine temperature. If the radiator cooler is in the loop then the heat goes into the radiator and if the coolant temp gets hot enough the fan will come on. It won't do that if only the trans gets hot.
Maybe all of the automakers don't know what they are doing when the spec both a radiator cooler and an air to oil cooler on all vehicles that tow.
The water to oil cooler inside the radiator is much more efficient at removing heat from the ATF than the largest air to oil cooler you can mount in a pickup. The water to oil heat transfer is MUCH more than you can get with air to oil.
And the difference in temperature between the radiator coolant and the ambient air? Not as much as you think it is.
The coolant where the ATF is being cooled is in the "cold" side of the radiator. This is the side where the coolant has already passed through the radiator to be cooled. It is not at engine temp, usually not even close.
I've measured extreme temperatures in my capacity as an Automatic Transmission Cooling Engineer at Ford. At VERY cold temperatures, such as -40F, the coolant in the cold side of the radiator didn't rise above about -30F. The coolant going into the radiator was about 200F. The engine thermostat only opens for a very short time before it cools off with -40F coolant coming into the engine. So the coolant in the radiator sits there with -40F air blowing over it. So the ATF goes into the radiator and sees coolant that is not above -30F. Kinda blows the whole heating the ATF myth out of the water, doesn't it? And remember, I measured these temperatures, I'm not just guessing how this works.
And in hot climates we only tested at +95F and above. When I ran trucks (up to the F-550) up 8% grades at max GCVW the temperature drop across the radiator would get down to as little as 15F. The "cold" side of the radiator was still cooler than the ATF. The transmission was also working very hard and generating a ton of heat. The radiator really helped keep the trans temps under control.
And where the radiator cooler really shines is where the air to oil coolers are next to useless is high load reversing. Try backing up a heavy trailer up a grade or on a soft surface. There is little to no airflow over the air to oil cooler so it does very little cooling. The fan clutch in these trucks won't react to transmission temperature, only engine temperature. If the radiator cooler is in the loop then the heat goes into the radiator and if the coolant temp gets hot enough the fan will come on. It won't do that if only the trans gets hot.
#17
07-08-2015, 09:51 PM
Yes, they call out replacing the existing external cooler AND adding another cooler.
I'm sure they have found that the original cooler doesn't clean out very well, so they want it replaced, not cleaned, and another cooler suggests they have found the stock setup is marginal.
Still, I'd love to know the actual GPM numbers that I'm getting.
FWIW I'm about to do Mark's trans flush and in preparing have noticed my '03 E250 w/5.4 has what seems to be a factory-type second cooler, the fluid flow being radiator first then to the second cooler before being returned to the trans. Not sure if the trans was replaced before me buying that van, if was factory original or added by the PO. No other E250's I've owned--all '97 and later---have had that second cooler.
factory-type second cooler, the fluid flow being radiator first then to the second cooler before being returned to the trans. Not sure if the trans was replaced before me buying that van, if was factory original or added by the PO. No other E250's I've owned--all '97 and later---have had that second cooler.Well, except for the deer damage!
Good stuff there. I hadn't realized the bottom of the radiator is that much colder. I wonder what the difference is in a side-flow radiator.
Of course the heat transfer efficiency of liquid-to-liquid is vastly higher than liquid-to-air.
What also counts is the heat differential. The higher it is, the faster heat transfers, and then dwell time comes into play.
I'd be interested in his take on my setup, specifically because it has TWO external coolers.
#18
07-09-2015, 06:32 AM
Perhaps we'll be fortunate to have Mr Mark Kovolsky drop in and share a few of his thoughts----OTOH he might be reading and would most likely add something if only to correct a myth or grave incorrect thought.
Glad this went so well for you Mr WirelessE----its been an interesting thread for sure.
As a heads up I found my local stealership had the absolute best price on Mercon V fluid, $5.28/qt. I'd been searching Amazon et al for the one gallon or 5 quart jugs, those running just at $40 minimum per---figures out to $8/qt
.
While I'd strongly prefer the larger jugs over 15 single quart bottles the cost savings was too much to pass by. The bottles and fluid will be recycled but still the jugs would have been more convenient.
Glad this went so well for you Mr WirelessE----its been an interesting thread for sure.
As a heads up I found my local stealership had the absolute best price on Mercon V fluid, $5.28/qt. I'd been searching Amazon et al for the one gallon or 5 quart jugs, those running just at $40 minimum per---figures out to $8/qt
. While I'd strongly prefer the larger jugs over 15 single quart bottles the cost savings was too much to pass by. The bottles and fluid will be recycled but still the jugs would have been more convenient.
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