[Meyergsr]

From what I can tell my 22 nine speed only has an external air to oil cooler. This is the reason it takes so long for the oil to warm up. I don't see any connections to the radiator. It connects directly to the transmission.

 

[zroger73]

There's a water-oil heat exchanger (ATF warmer in the diagram below) through which coolant and ATF pass as well.

 

[HRL383]

The t-stat "closed" portion of that diagram shows no engine coolant flow thru the hockey puck.

 

[F6Hawk]

The t-stat "closed" portion of that diagram shows no engine coolant flow thru the hockey puck.

It also shows that the water interacting with the tranny fluid is the cooler water from the radiator, not the hotter water from the engine.

 

[wjfyfe]

Well, I thought after digesting all the posts shared on this forum over the years, I was confident that I had the 6-speed's failure issue's all nailed down, at least before I purchased the ScanGauge. With our first fluid analysis we can see that at 35,000 miles the fluid is at the end of it's useful life. With all of the anecdotal evidence provided up to that time the answer was obvious, most everybody were convinced that the fluid was getting over-heated, breaking down, and thus taking the transmission with it. Now after installing the ScanGauge it appears that over-heating is really not an issue at all, at least in a non-towing vehicle, (the jury is still out while towing.) So apparently it is back to square one with determining the cause of the seemingly rapid fluid deterioration in the 6-speed, though at least the remedy still should be the same, replacing single dump-n-fills with multiple dump-n-fills?

Bill

 

[zroger73]

With our first fluid analysis we can see that at 35,000 miles the fluid is at the end of it's useful life.

So apparently it is back to square one with determining the cause of the seemingly rapid fluid deterioration in the 6-speed, though at least the remedy still should be the same, replacing single dump-n-fills with multiple dump-n-fills?

According to this post, the exact quote from Blackstone was, "The viscosity came in thin, and for ATF that's a sign that it's nearing the end of its useful life." There is a different between at and nearing.

They measured viscosity at 4.9 and stated that the range should be 5.1-7.9. Less than 1,000 miles later, they said it should be 4.5-7.3. Do they really expect viscosity to change by that amount in that distance? I question where they're getting these numbers and strongly doubt their significance. Realistically, there's relatively little difference in viscosity between the lowest and highest they measured and stated. To put this into perspective, water has a kinematic viscosity of 0.3163, olive oil measures 43.2, and glycerin measures 176 at 100ºC. Now, think about where viscosities from 4.5 to 7.9 fall.

Don't forget the 6-speed failures that occurred before 35,000 miles...or even 10,000 miles. Do you think we should perform a 3x ATF drain-and-fill at every engine oil change?

 

[wjfyfe]

According to this post, the exact quote from Blackstone was, "The viscosity came in thin, and for ATF that's a sign that it's nearing the end of its useful life." There is a different between at and nearing.

You really believe that there is a difference between the two terms to construe as being significantenough to make an argument?

Don't forget the 6-speed failures that occurred before 35,000 miles...or even 10,000 miles. Do you think we should perform a 3x ATF drain-and-fill at every engine oil change?

Where on earth have you come up with that I have ever proposed doing 3X ATF drain-n-fills every engine oil change?

(Isn't it interesting to note who gave a thumbs up to this post? )

Bill

 

[HRL383]

It also shows that the water interacting with the tranny fluid is the cooler water from the radiator, not the hotter water from the engine.

The other diagram I'm referring to shows coolant flow when the t-stat is closed. When closed, coolant does not flow thru the hockey puck. Monitoring CT2 and TFT verifies this from a cold start.

 

[F6Hawk]

The other diagram I'm referring to shows coolant flow when the t-stat is closed. When closed, coolant does not flow thru the hockey puck. Monitoring CT2 and TFT verifies this from a cold start.

The diagram just shows the path the water takes. Obviously, the water cannot flow past the thermostat until it warms up, which means that ATF warmer is doing nothing at first, until the water temp is high enough to keep the t-stat open. And when that first happens, the water flowing thru the warmer will still be ambient.

What would be interesting to see is a graph (or at least your experience) of which heats up faster, the water or the ATF. Until the ATF reaches 195°, the water is warming it. Once the ATF exceeds 195°, the water is cooling it.

 

[stevem5215]

 

[wjfyfe]

@stevem5215, what was your OAT?

Going back and forth to work this week, a 30 minute drive @ 60MPH, in the mornings with OAT into the 30s, TFT are getting into the 120s. Coming home with OAT reaching maybe into the 70s, I am seeing TFT only into the 130s?

On our first extended drive with the ScanGauge last weekend of approximately 100 miles, with outside Air Temp: 45 plus/minus 5 and speed 55 plus/minus 10, we finally reached a maximum TFT of 140 plus/minus 5

A real test is coming up next weekend when we will be taking our loaded Ridgeline, towing a 4500 pound trailer, 2000 miles plus round trip over the Cascade and Rocky Mountains. Knowing what I know now, I am having a sneaking suspicion that my theory up to now about using D4 is going to get blown to hell!

Bill

 

[zroger73]

The other diagram I'm referring to shows coolant flow when the t-stat is closed. When closed, coolant does not flow thru the hockey puck.

Obviously, the water cannot flow past the thermostat until it warms up, which means that ATF warmer is doing nothing at first, until the water temp is high enough to keep the t-stat open.

I haven't looked closely at the thermostat used in the Ridgeline, but in some other thermostats I've seen, there's a bypass hole instead of a jiggle pin through which a small amount of coolant flows even when the thermostat is fully closed.

 

[stevem5215]

@stevem5215, what was your OAT?

Going back and forth to work this week, a 30 minute drive @ 60MPH, in the mornings with OAT into the 30s, TFT are getting into the 120s. Coming home with OAT reaching maybe into the 70s, I am seeing TFT only into the 130s?

On our first extended drive with the ScanGauge last weekend of approximately 100 miles, with outside Air Temp: 45 plus/minus 5 and speed 55 plus/minus 10, we finally reached a maximum TFT of 140 plus/minus 5

A real test is coming up next weekend when we will be taking our loaded Ridgeline, towing a 4500 pound trailer, 2000 miles plus round trip over the Cascade and Rocky Mountains. I am having a sneaking suspicion that my theory up to now about using D4 is going to get blown to hell!

Bill

https://www.accuweather.com/en/us/pittsburgh/15219/october-weather/1310?year=2021

history from accuweather.com

 

[HRL383]

I haven't looked closely at the thermostat used in the Ridgeline, but in some other thermostats I've seen, there's a bypass hole instead of a jiggle pin through which a small amount of coolant flows even when the thermostat is fully closed.

I've never seen a closed t-stat that sealed perfectly water tight....ECT rises rather quickly after start-up due to virtually all coolant being recirculated thru the block/heads (heater core depending on design) until the t-stat opens/allows coolant circulation throuought all of the cooling system. A jiggle valve only opens when the motor is off (to bleed air).....otherwise, coolant flow keeps the jiggle valve closed due to circulation.

 

[SimiMike]

I was towing approx. 3500lbs over the weekend. These are the temps I was seeing. I snapped the pic during a traffic back up on the highway. I have never seen over 160 towing so far. It's around 100 not towing. Outside temp was around 60 at the time.
View attachment 424797

207 Degrees is fine, in fact perfect for any normal driving conditions in a late model vehice. The new synthetic ATFs are designed for 300 deg.+.

Having been in the trans business for 40+ years my experience has been that most all vehicles built in the last couple of decades or longer have a safety function built into the ECM/TCM that when it gets to a temp that the manufacturer feels is too hot it turns the TCC off to bring the temp down, and in some cases also disables OD until the temp is back in specs.

It is possible to over cool a trans, especially in areas like the NE states that see temps in the teens or lower for long periods of time. Most transmissions have to get up to a certain temp ( usually in the 140-degree+ area ) for TCC & shift points to function as designed. There are a lot of vehicles that have bypasses built into the trans cooler lines that work similar to an engine thermostat & bypass the fluid back to the trans until it reaches a certain temp & opens up to let fluid go through the cooler.

One of the worse things I've seen car owners do over the years is to install a trans temp gauge without understanding the proper temps of a trans & they start freaking out over nothing when they see 225-250 degrees on the gauge which is totally acceptable in some instances.

That said if a vehicle is being used under more severe conditions than normal ( constant towing, loaded most of the time, etc. ) then an add-on external cooler could be considered. BUT not by-passing the factory cooler unless a larger cooler is used. All aftermarket cooler GVW ratings are rated figuring the OE trans cooler is still in place. Example: If you are wanting to add an external cooler with a 10,000 GVW rating & are planning on bypassing the OE cooler then get an external cooler rated in the 15,000+ GVW rating. Increase the cooler rating by 50% or more.

I could go on & on about this topic because I've seen so much BS & misinformation toss around over the years. Todays vehicles are not the same as last centuries, but people still treat them as if they should be treated, repaired & upgraded like they are.

If it ain't broke don't fix it.

 

[zroger73]

...it turns the TCC off to bring the temp down...

Do you mean on since turning the TCC off results in a difference in rotational speed between the torque converter's turbine and impeller and more fluid friction thus more heat generated?

 

[wjfyfe]

207 Degrees is fine, in fact perfect for any normal driving conditions in a late model vehice. The new synthetic ATFs are designed for 300 deg.+.

Thank you SimMike for that information. You discussed the higher temps in automatic transmissions, how about a little more information operating at lower temps? For example, with our stock 2019 commuting 30+ miles a day, (one way), with OAT at 30-60 degrees, my transmission temps are sneaking up to maybe 110-130 degree range, should I also consider this to be "normal?"

Bill

 

[Happy Tom]

There's a water-oil heat exchanger (ATF warmer in the diagram below) through which coolant and ATF pass as well.

View attachment 424912

Thanks for this diagram, I wasn't aware that the throttle body was warmed by a coolant circuit. Is this commonly used in other vehicles? I assume it provides better driving in cold conditions and may reduce emissions....

 

[wjfyfe]

Thanks for this diagram, I wasn't aware that the throttle body was warmed by a coolant circuit. Is this commonly used in other vehicles? I assume it provides better driving in cold conditions and may reduce emissions....

Our two "classic" pickups use exhaust channeled through the intake manifold to warm the carburetor, I am assuming warming the throttle body in our Ridgelines is basically the same idea?
Bill

 

[zroger73]

Thanks for this diagram, I wasn't aware that the throttle body was warmed by a coolant circuit. Is this commonly used in other vehicles? I assume it provides better driving in cold conditions and may reduce emissions....

Yes - it is common. In cold, humid conditions, ice can form between the throttle blade and bore of the throttle body causing the throttle blade to stick. Heating the throttle body helps prevent that from happening.