High Transmission Temperature

[ptjones]

I have been getting up to 250*F Transmission Fluid Temp (TFT) on my ScanGaugeII. Contacted my local FORD SM and asked him what the normal operating temps for the TFT and he came back with 200-220*F. Then I got worried.  

I just talked to a FORD AutoNation (Electric Dealer) SW who talked to Transmission Specialist who looked it up and said it(Transmission Electronics) will trip a code at 301*F and come up with a wrench symbol. I'm surprised that it could go that high without hurting something. I'm not really having any problems with the Transmission. ;)

 

Paul

[fbov]

I should have thought about this sooner.

 

We're all thinking like it's an automatic, a hydraulic transmission with a torque converter that uses transmission fluid to convey power. Answers like "better to stay at 180F" and "you'll kill the tranny at 240F" are true for these devices (speaking as a former class-A motorhome owner who took it over the Rockies).

 

However, if you look at the hybrid synergy drive, it's more of a manual transmission than an automatic, especially when it comes to the stresses placed on the transmission fluid (which is ATF, by the way). There's no torque converter, no gears shifting, no valves to get stuck, and a whole lot less bulk mechanical stress, even if the oil film stresses are high when the gears are in mesh. I see no reason to expect the kind of failure modes that plaque conventional automatics when their AFT heats up.

 

Your thoughts?

Frank

[SPL Tech]

fbov, on 19 Feb 2015 - 10:33 AM, said:

I should have thought about this sooner.

 

We're all thinking like it's an automatic, a hydraulic transmission with a torque converter that uses transmission fluid to convey power. Answers like "better to stay at 180F" and "you'll kill the tranny at 240F" are true for these devices (speaking as a former class-A motorhome owner who took it over the Rockies).

 

However, if you look at the hybrid synergy drive, it's more of a manual transmission than an automatic, especially when it comes to the stresses placed on the transmission fluid (which is ATF, by the way). There's no torque converter, no gears shifting, no valves to get stuck, and a whole lot less bulk mechanical stress, even if the oil film stresses are high when the gears are in mesh. I see no reason to expect the kind of failure modes that plaque conventional automatics when their AFT heats up.

 

Your thoughts?

Frank

 

 

 

 

 

One problem: ATF bakes a high temps, and the lubricating properties nearly disappear when the oil is flash heated. You can tell as the oil turns brown and smells burnt. Even if the oil is 10 miles old, if the oil overheats it's dead and needs to be replaced immediately. Not sure about the Mercon LV used in the Ford transaxle, but most ATF will only last about 30k at 220F, which is very far short of the 150k that Ford recommends between changes (or 100k, I forget which).

 

I would take it into the shop under the 8/100k hybrid warranty which covers the transaxle.

 

A good option would be to call a major oil company and ask them what the max temp for their Mercon LV fluid is if it's expected to be changed at 150k intervals in a sealed tranny. Specify you have the CMAX.

Edited February 21, 2015 by SPL Tech

[drdiesel1]

One problem: ATF bakes a high temps, and the lubricating properties nearly disappear when the oil is flash heated. You can tell as the oil turns brown and smells burnt. Even if the oil is 10 miles old, if the oil overheats it's dead and needs to be replaced immediately. Not sure about the Mercon LV used in the Ford transaxle, but most ATF will only last about 30k at 220F, which is very far short of the 150k that Ford recommends between changes (or 100k, I forget which).

 

I would take it into the shop under the 8/100k hybrid warranty which covers the transaxle.

 

A good option would be to call a major oil company and ask them what the max temp for their Mercon LV fluid is if it's expected to be changed at 150k intervals in a sealed tranny. Specify you have the CMAX.

 

 

 

The C-Max HF35 is not a sealed unit. It has a fill and drain plug.

Edited February 21, 2015 by drdiesel1

[ptjones]

fbov, on 19 Feb 2015 - 10:33 AM, said:

I should have thought about this sooner.

 

We're all thinking like it's an automatic, a hydraulic transmission with a torque converter that uses transmission fluid to convey power. Answers like "better to stay at 180F" and "you'll kill the tranny at 240F" are true for these devices (speaking as a former class-A motorhome owner who took it over the Rockies).

 

However, if you look at the hybrid synergy drive, it's more of a manual transmission than an automatic, especially when it comes to the stresses placed on the transmission fluid (which is ATF, by the way). There's no torque converter, no gears shifting, no valves to get stuck, and a whole lot less bulk mechanical stress, even if the oil film stresses are high when the gears are in mesh. I see no reason to expect the kind of failure modes that plaque conventional automatics when their AFT heats up.

 

Your thoughts?

Frank

 

 

 

 

 

One problem: ATF bakes a high temps, and the lubricating properties nearly disappear when the oil is flash heated. You can tell as the oil turns brown and smells burnt. Even if the oil is 10 miles old, if the oil overheats it's dead and needs to be replaced immediately. Not sure about the Mercon LV used in the Ford transaxle, but most ATF will only last about 30k at 220F, which is very far short of the 150k that Ford recommends between changes (or 100k, I forget which).

 

I would take it into the shop under the 8/100k hybrid warranty which covers the transaxle.

 

A good option would be to call a major oil company and ask them what the max temp for their Mercon LV fluid is if it's expected to be changed at 150k intervals in a sealed tranny. Specify you have the CMAX.

Here is a Link to MERCON LV Trans Fluid:  www.fcsdchemicalsandlubricants.com/main/additionalinfo/Product Data Sheet MERCON LV.pdf

 

The Flash point for it is 421*F , 120*F higher than trip temp. :)

 

Paul

[plus 3 golfer]

I have been getting up to 250*F Transmission Fluid Temp (TFT) on my ScanGaugeII. Contacted my local FORD SM and asked him what the normal operating temps for the TFT and he came back with 200-220*F. Then I got worried.  

I just talked to a FORD AutoNation (Electric Dealer) SW who talked to Transmission Specialist who looked it up and said it(Transmission Electronics) will trip a code at 301*F and come up with a wrench symbol. I'm surprised that it could go that high without hurting something. I'm not really having any problems with the Transmission. ;)

 

Paul

Under what conditions are you getting 250 F?  

 

The shop manual shows typical TOT (transmission oil temperature) and gen / motor temps for normal conditions at certain speeds -- ambient 75 F, acc. off, and engine up to operating temperature at 30 mph and 55 mph and such temperatures are a lot lower than 250 F (about 50% lower).  I can't image getting up to 250 F unless ambient were extremely high, high speed driving, or grille blocks. 

[ptjones]

Under what conditions are you getting 250 F?  

 

The shop manual shows typical TOT (transmission oil temperature) and gen / motor temps for normal conditions at certain speeds -- ambient 75 F, acc. off, and engine up to operating temperature at 30 mph and 55 mph and such temperatures are a lot lower than 250 F (about 50% lower).  I can't image getting up to 250 F unless ambient were extremely high, high speed driving, or grille blocks. 

Thanks for the info Ken.  Around town driving TFT stays under 200*F but not 125*F . Can you monitor your TFT?   At this point I think we need to test several CMAXs and see what Trans temps they are running on the FWY. ;)

 

Paul

[drdiesel1]

Thanks for the info Ken.  Around town driving TFT stays under 200*F but not 125*F . Can you monitor your TFT?   At this point I think we need to test several CMAXs and see what Trans temps they are running on the FWY. ;)

 

Paul

I should be able to get a chance to monitor mine today. I'll post my results for you.

I will be using my Ford IDS to get the data, so mine will be accurate info.

[ptjones]

I should be able to get a chance to monitor mine today. I'll post my results for you.

I will be using my Ford IDS to get the data, so mine will be accurate info.

Thanks for the Help. Do you have a CMAX Hybrid and NRG?  We need the Temps for Hybrid. Thanks again. :)

 

Paul

[drdiesel1]

Thanks for the Help. Do you have a CMAX Hybrid and NRG?  We need the Temps for Hybrid. Thanks again. :)

 

Paul

NRG with the pump :wub2:

[plus 3 golfer]

Thanks for the info Ken.  Around town driving TFT stays under 200*F but not 125*F . Can you monitor your TFT?   At this point I think we need to test several CMAXs and see what Trans temps they are running on the FWY. ;)

 

Paul

Here's the reference values from the manual.  Ford says "Reference values may vary 20% depending on operating conditions, altitude, and other factors. The RPM values are axle and tire dependent.  Values are taken at an altitude of approximately 189 meters (620 ft) above sea level with the engine at normal operating temperature and accessories off."  

 

I'll have to input the PID for the transmission temperature.  I may not get around to it until next weekend..

 

TOT = Transmission Oil Temperature

GCLTEMP = Generator Coil Temperature

MCLTEMP = Motor Coil Temperature.

 

[ptjones]

NRG with the pump :wub2:

Hybridbear has a NRG FFH and His highest TFT  was 170*F at 70*FOT on trip to CA because the pump runs all the time.  When I'm driving on the FWY I  EV 25-40% of the time which allows Temps to go up when ICE is not running and circulating Trans Fluid. ;)

 

Paul

[SPL Tech]

The C-Max HF35 is not a sealed unit. It has a fill and drain plug.

Why doesent it have a dip stick then? And why is the ATF rated for 150k while other trannys on new cars are rated for 50k?

[SPL Tech]

 

 

The Flash point for it is 421*F , 120*F higher than trip temp. :)

 

Paul

What does that matter? Flash point is the minimum temperature in which the substance can burn when vaporized into the air. I dont see how that matters here at all. ATF is destroyed well before it's flash point.

 

Anyway, the lifespan of the ATF is still in question.

[drdiesel1]

Why doesent it have a dip stick then? And why is the ATF rated for 150k while other trannys on new cars are rated for 50k?

 

Dude....... Get a grip.   It's setup like a manual transmission because it doesn't use fluid power like a

conventional trans with a torque converter. Try thinking about this stuff before you light your hair on fire

and run off like a crazed lunatic.

 

I have no idea why they would rate it for 150K. Maybe because it's not conventional. I really don't

care what they rate things at. I'm always gonna service my stuff as I see fit. You can follow any plan you like.

Edited February 23, 2015 by drdiesel1

[ptjones]

What does that matter? Flash point is the minimum temperature in which the substance can burn when vaporized into the air. I dont see how that matters here at all. ATF is destroyed well before it's flash point.

 

Anyway, the lifespan of the ATF is still in question.

I suggest you bring that up with FORD.  This  morning I had the Trans Heater on for three hours and It was reading 148*F with garage temp of 57*F.  My HVB was low so the ICE started up immediately and TFT dropped to 132*F quickly and back up to 136*F by the time I got to work in 2.4mi., an indication that the Trans pump is working some, OT was 41*F. :)

 

Paul

[fbov]

Why doesent it have a dip stick then? And why is the ATF rated for 150k while other trannys on new cars are rated for 50k?

 

... It's setup like a manual transmission because it doesn't use fluid power like a convention trans with a torque converter. ...

I'd give this a +1 but for the severe editing required to remove off-topic nonsense. It's the point of post #2 - very different stresses on the oil in a CVT than a multispeed hydraulic automatic, much more like engine oil. It's quite possible that the transmission runs fine with burnt fluid... or what we think we know about hydraulic automatics is wrong.

 

We're quoting tranny cooler input temps, as that's where the sensor is. Instantaneous, local temperatures within the torque converter may be quite a bit higher, albeit in places where you can't put a sensor. I've always had a hard time with the idea that tranny fluid broke down around the boiling point of water. Oils, in general, don't break down at 100C. 200C is a different story. Any cook knows that...

 

Have fun,

Frank

[Bill-N]

Just to be clear, the C-Max transmission does not have a torque converter.  The planetary gear set and motor/generators replace all that.

 

 

Cheers.

[ptjones]

Here are the right numbers for the XGauge for Trans Fluid Temp for the ScanGaugeII:

 

TXD: 07E6221E1C

RXF: 0462051E061C

RXD: 3010

MTH: 000900500020

NAM: TFT

 

 

 

:) Paul

Edited March 12, 2015 by ptjones

[drdiesel1]

I'd give this a +1 but for the severe editing required to remove off-topic nonsense. It's the point of post #2 - very different stresses on the oil in a CVT than a multispeed hydraulic automatic, much more like engine oil. It's quite possible that the transmission runs fine with burnt fluid... or what we think we know about hydraulic automatics is wrong.

 

We're quoting tranny cooler input temps, as that's where the sensor is. Instantaneous, local temperatures within the torque converter may be quite a bit higher, albeit in places where you can't put a sensor. I've always had a hard time with the idea that tranny fluid broke down around the boiling point of water. Oils, in general, don't break down at 100C. 200C is a different story. Any cook knows that...

 

Have fun,

Frank

That's ok.... No one asked you to edit my post or grade my response. If it's a problem for

you, just ignore it.  Thanks!

[ptjones]

:)

Edited February 25, 2015 by ptjones

[ptjones]

  There is a drain plug and a filler plug on top for changing Trans Fluid.   But changing Fluid isn't a trivial thing to do if you have to take the air cleaner off coming from experience with cut up hands replacing the Air Filter.  I wonder if it is possible to do with out removing air cleaner?

 

Paul

Edited February 25, 2015 by ptjones

[drdiesel1]

  There is a drain plug and a filler plug on top for changing Trans Fluid.   But changing Fluid isn't a trivial thing to do if you have to take the air cleaner off coming from experience with cut up hands replacing the Air Filter.  I wonder if it is possible to do with out removing air cleaner?

 

Paul

It's all done from under the car. The drain plug is on the bottom and the fill plug is on the side.

Just remove the closeout panel just like when you change the oil. You can see both plugs.

You will need some type of fluid pump to fill it.

[ptjones]

It's all done from under the car. The drain plug is on the bottom and the fill plug is on the side.

Just remove the closeout panel just like when you change the oil. You can see both plugs.

You will need some type of fluid pump to fill it.

Thanks drdiesel1, I have the Service Manual on CD. See .pdf below!

 

Paul307-01 Automatic Transmission.pdf

Edited February 26, 2015 by ptjones

[jdbob]

Thanks drdiesel1, I have the Service Manual on CD. See .pdf below!

 

Paul307-01 Automatic Transmission.pdf

 

Interesting, that procedure was revised 1/24/2013.

 

The online version was revised 8/7/2013 and shows doing it all from below.

 

Maybe they decided it was cheaper not to have to remove the air filter and cowl panel and use a pump instead.