[ARB1977]

It’s no different than my 15 Tacoma transmission. In my truck I measure what comes out cold. Add that much plus half to a qrt more. I use a Bluetooth OBD reader and the Fusion app to read the transmission temp. Once the temp is met. Remove the level plug till the fluid stops trickling, done.

 

[cintocrunch]

I got an A in thermo an don't care to revisit it... I just want someone to give me the information now.

 

[Daltongang]

I got an A in thermo an don't care to revisit it... I just want someone to give me the information now.

Short answer, yes it expands. That's the reason for the hot transmission fluid check procedure for those with dipsticks. Transmission dipsticks, not relatives. 😆

 

[cintocrunch]

Short answer, yes it expands. That's the reason for the hot transmission fluid check procedure for those with dipsticks. Transmission dipsticks, not relatives. 😆

But how much... too many of those variables I don't care to hunt for... if only I knew someone retired who could use a Friday project...

So tell me the volume of whatever transmission fluid you can find info for (3.1, maxlife, dw-1) at 80 degrees vs 180 degrees.

 

[Daltongang]

But how much... too many of those variables I don't care to hunt for... if only I knew someone retired who could use a Friday project...

So tell me the volume of whatever transmission fluid you can find info for (3.1, maxlife, dw-1) at 80 degrees vs 180 degrees.

"Give a Man a Fish, and You Feed Him for a Day. Teach a Man To Fish, and You Feed Him for a Lifetime"
I gave you the tools to "fish" so if you want fish for dinner, ya gotta pick up the tools. 😁 😁

 

[Nail Grease]

I got an A in thermo an don't care to revisit it... I just want someone to give me the information now.

Short answer, yes it expands. That's the reason for the hot transmission fluid check procedure for those with dipsticks. Transmission dipsticks, not relatives. 😆

Set my new ATF outside in the cold so it will be the same temp as what drains out.
I'm a rebel on a lot of things Honda. Measuring the amount of ATF drained out on a 9-speed and using that as a benchmark to refill is not one of them. Regardless of temperature.

 

[cintocrunch]

"Give a Man a Fish, and You Feed Him for a Day. Teach a Man To Fish, and You Feed Him for a Lifetime"
I gave you the tools to "fish" so if you want fish for dinner, ya gotta pick up the tools. 😁 😁

I already told you, I got an A in thermo... so I'm a pro fisherman in this case. I just don't like to fish anymore and eat meat so I'm instructing the amateur fisherman with the time on his hands to do it for me.

Makes me think... since I've always preferred experiments and tangible evidence to theoretical calcs... maybe next time I do an ATF D&F I will measure what comes out and the temperature it's at and see how much the volume changes when the temp drops to ambient.

 

[Daltongang]

Oh all right......
Coefficient of thermal expansion for oils and transmission fluids is around 0.0007 per degree C (0.07%/C). So, if you've got 12 liters in the pan, it will expand 0.0084 L per degree C. Since there's increased volume, and the surface area of the fluid does not change appreciably, the fluid goes higher on the dipstick. Volume = Area x Height. So, Height = Volume/Area. Therefore, height on the dipstick is proportional to volume change. Summer time temperature change might be ambient air temperature 68F (20C), at start up, to around 180F(82C) at operating temperature. Or, around 62C. Therefore, during the summertime, the fluid could be expected to expand 0.0007 x 62C = 0.0434 (4.3%).

Maybe this will help. For the NAG 1 transmission.

Happy now?????

 

[Daltongang]

I already told you, I got an A in thermo... so I'm a pro fisherman in this case. I just don't like to fish anymore and eat meat so I'm instructing the amateur fisherman with the time on his hands to do it for me.

Makes me think... since I've always preferred experiments and tangible evidence to theoretical calcs... maybe next time I do an ATF D&F I will measure what comes out and the temperature it's at and see how much the volume changes when the temp drops to ambient.

Oh yeah, Here is one more equation for you since you have kids......

😁 😆 😅😂🤣

 

[Nail Grease]

Oh all right......
Coefficient of thermal expansion for oils and transmission fluids is around 0.0007 per degree C (0.07%/C). So, if you've got 12 liters in the pan, it will expand 0.0084 L per degree C. Since there's increased volume, and the surface area of the fluid does not change appreciably, the fluid goes higher on the dipstick. Volume = Area x Height. So, Height = Volume/Area. Therefore, height on the dipstick is proportional to volume change. Summer time temperature change might be ambient air temperature 68F (20C), at start up, to around 180F(82C) at operating temperature. Or, around 62C. Therefore, during the summertime, the fluid could be expected to expand 0.0007 x 62C = 0.0434 (4.3%).

Maybe this will help. For the NAG 1 transmission.
View attachment 158359

Happy now?????

Stop! Lol you win

 

[beemerphile]

... so I'm instructing the amateur fisherman with the time on his hands to do it for me.

"Instructing" a volunteer resource to solve a problem that one knows how to, but doesn't want to expend the effort to solve? 🤔

 

[ARB1977]

Set my new ATF outside in the cold so it will be the same temp as what drains out.
I'm a rebel on a lot of things Honda. Measuring the amount of ATF drained out on a 9-speed and using that as a benchmark to refill is not one of them. Regardless of temperature.

I did that to my Tacoma. The fluid was at 97 degrees before stating the truck up. Which is the staring fluid temp. Stared it up as the fluid came out. All was good during the drive. May irk on the Pilot as well.

 

[cintocrunch]

"Instructing" a volunteer resource to solve a problem that one knows how to, but doesn't want to expend the effort to solve? 🤔

Part of being a good manager is knowing how to motivate others to do work that you yourself can do but are too busy to do. This particular subject is retired and does not make dinner on Fridays since it is takeout day. Knowing said subject has more time on his hands and also has a general thirst for knowledge and is also an administrator on this very forum, it was pretty easy to do.

And this is why I left the position that had me managing people and am now responsible for my own work, it's tiring and annoying when met with resistance and I'd rather spend my time solving problems than playing babysitter.

 

[viper74656]

Measuring what came out and using that to refill won't work on the 9-speed. Something in the internal workings means more of the fluid drains to the sump out of the torque convertor than does on the 6-speed. This is why the fill procedure is so complicated.

When I did the fluid change on my ZF8-equipped vehicle (same procedure) I got in another 1.5 qts easy AFTER doing the prescribed "drive simulation". You simply couldn't get the full amount in without the drive cycle, because the "extra" fluid is still filling the pan rather than circulating up in the torque convertor. Before doing the "drive simulation" the fluid level is at the fill hole. Afterwards, there is room for quite a bit more fluid.

 

[ls973800]

We know that not all fluids expand or contract at the same rate or amount. Supposedly the Honda 3.1 fluid expands a lot with heat hence the specific instructions for doing the Honda written instructions for checking the proper level when certain conditions including fluid temps are met.

Easy enough to avoid any doubt by leaving the car level in the garage overnight along side the replacement fluid. Drain using an oil drain pan which will catch any fluid coming from the drain hole big enough that holds 6 or more quarts, less chance of spilling when pouring into a measuring container with larger pans.

Pour the removed fluid into an inexpensive measuring container you can pick up at Lowes, Home Depot, Dollar Tree, etc that has markings usually in ounces and mls. I have learned from experience NOT to use my wife's turkey baster or measuring cups for garage or automotive use! Measure the exact amount that came out and put in the same exact amount. Done!

If there are any visible signs of transmission fluid leaks or transmission performance problems, then you may want to have the fluid checked the Honda way to make sure you have the correct amount in there to begin with. If you are the first owner then you know how the transmission has performed and you can confidently change the fluid yourself with just a drain and fill, IMHO.

I use four Rhino Ramps Max and drive the Pilot onto them for a level and elevated vehicle. I found them for $49.99 a pair on Amazon but see they have gone up since then.

Rhino Ramps Max

 

[Daltongang]

Part of being a good manager is knowing how to motivate others to do work that you yourself can do but are too busy to do. This particular subject is retired and does not make dinner on Fridays since it is takeout day. Knowing said subject has more time on his hands and also has a general thirst for knowledge and is also an administrator on this very forum, it was pretty easy to do.

And this is why I left the position that had me managing people and am now responsible for my own work, it's tiring and annoying when met with resistance and I'd rather spend my time solving problems than playing babysitter.

 

[ls973800]

Quick honest question. Remove the transmission fluid while it is hot into one pan and then allow it to cool to room temperature. Once cooled and if the transmission had been factory filled to the correct specification of 3.5-3.75 quarts, wouldn't the fluid you removed have shrunk or contracted back to the 3.5-3.75 quarts? While it is hot inside the transmission it may have expanded but it didn't grow in quantity or amount.

Should be no problem draining the fluid while it is hot as long as you put the correct amount back in, which would be the 3.5-3.75 quarts.

 

[AVC]

The measuring of what comes out is going to be the trouble. It's always going to be different for each vehicle, depending on temperature, how long the vehicle has sat and what grade the vehicle is parked on. Give us an absolute number, cold (sitting overnight), on level ground, then I'd be more comfortable with a drain and fill.

We've prattled on and on and on in the 2nd Gen forum. From another engineering perspective; if you have a vehicle that has sat overnight, is on a level floor, you drain out 3.5 qts at that "room temp" and the new bottle you pour in 3.5 qt from is at the same room temp, it'll be exactly putting in what came out. I add a whiff (short of an ounce) to make up for any residue that stuck to the drain pan that didn't make it in the measurement. Note the final amount (measure once, drain and fill many over the service life). Close enough, except for the OCD on your forum who think an unpowered drivetrain (engine off, key off) somehow magically knows you are draining and filling.

 

[Daltongang]

We've prattled on and on and on in the 2nd Gen forum. From another engineering perspective; if you have a vehicle that has sat overnight, is on a level floor, you drain out 3.5 qts at that "room temp" and the new bottle you pour in 3.5 qt from is at the same room temp, it'll be exactly putting in what came out. I add a whiff (short of an ounce) to make up for any residue that stuck to the drain pan that didn't make it in the measurement. Note the final amount (measure once, drain and fill many over the service life). Close enough, except for the OCD on your forum who think an unpowered drivetrain (engine off, key off) somehow magically knows you are draining and filling.

Thus the call for a good digital scale, weigh the catch container empty, then weigh the catch container with what ever you drained, subtract the weight of the catch container and you have the weight of what you drained. Then measure out the same weight of new fluid to replace the old.

 

[viper74656]

We've prattled on and on and on in the 2nd Gen forum. From another engineering perspective; if you have a vehicle that has sat overnight, is on a level floor, you drain out 3.5 qts at that "room temp" and the new bottle you pour in 3.5 qt from is at the same room temp, it'll be exactly putting in what came out. I add a whiff (short of an ounce) to make up for any residue that stuck to the drain pan that didn't make it in the measurement. Note the final amount (measure once, drain and fill many over the service life). Close enough, except for the OCD on your forum who think an unpowered drivetrain (engine off, key off) somehow magically knows you are draining and filling.

This is perfect for any Honda transmission, but the ZFs just don't appear to work this way. The "simulated drive cycle" to work the new fluid from the pan up into the torque convertor, before rechecking the level is standard across the ZF lineup. A standard drain and fill will almost certainly leave the transmission down a quart or 2 on fluid.

How to Change the Transmission Oil on a Passenger Car

Transmission oil change

aftermarket.zf.com