Checking automatic transmission fluid question

[mtnbkr]

I know as an adult I should know this, but I've owned very few automatics and none as long as this one.

It's a 2007 Honda Odyssey with 165k miles. No issues currently, but the transmission was replaced under warranty at 98k miles (was showing very early signs of failure).

Recently, I did a scheduled transmission oil change and filled it up with the prescribed amount of Honda-branded fluid. Everything went smoothly and the transmission hasn't shown any issues since.

The problem is when I went to check the fluid. Per the instructions, I am to check the fluid with the transmission fully warmed up (supposedly by the time the engine cooling fans turn on). I shut the engine down and wait 60 seconds, but not more than 90 seconds and check the fluid via the dip stick. This is exactly what the owner's manual says.

When I do that, the oil volume is either at the very bottom of the dipstick (ie very low) or randomly smeared up and down the dipstick and virtually impossible to read accurately. I can get variations of that checking multiple times in a row.

There are no leaks and the transmission shifts and drives like it should.

If I check when it's cold, the fluid is halfway between the low and high marks.

I know ATF expands while hot, which is why you check it after the transmission is warmed up, but it makes no sense that the volume would be ok when cold and low when hot.

I don't want to add more if it's not low, but my inability to get an accurate or logical reading when the transmission is warm has me concerned.

Thoughts? Suggestions? Everything I read on Honda boards is a mix of "follow the manual" or "check it while hot, that's what the infallible Honda Engineers said you should do" or "I check it cold and it reads the same as hot". Should I just remain confident that the cold reading at halfway between low and high is accurate and thermal expansion would put it to the high mark?

Chris

[hufnagel]

Don't feel bad; i've been a car guy since before my teens and I didn't see an automatic until I got married in my late 20s. I still struggle with reading the damn dipstick on autos sometimes. The fact that the reading window is often moronically narrow and a specific "dance" that's dependent on the vehicle doesn't help. The one "trick" I learned is that sometimes it'll wick/contaminate less if you rotate the dipstick 180* and put it back in. Experiment with how you pull the dipstick out in terms of speed and/or alignment. As a last resort, go to a trusted shop and ask them to check it and show you what they do so you can learn.

[Hambo]

Recently, I did a scheduled transmission oil change and filled it up with the prescribed amount of Honda-branded fluid. Everything went smoothly and the transmission hasn't shown any issues since.



You did it, or had it done? Just wondering because on my truck, a total transmission fluid change (not just what's in the pan) is a major PITA.

[mtnbkr]

Don't feel bad; i've been a car guy since before my teens and I didn't see an automatic until I got married in my late 20s. I still struggle with reading the damn dipstick on autos sometimes. The fact that the reading window is often moronically narrow and a specific "dance" that's dependent on the vehicle doesn't help. The one "trick" I learned is that sometimes it'll wick/contaminate less if you rotate the dipstick 180* and put it back in. Experiment with how you pull the dipstick out in terms of speed and/or alignment. As a last resort, go to a trusted shop and ask them to check it and show you what they do so you can learn.

I tried that (changing dipstick orientation) thinking that may be the issue. It didn't help.

Going to a shop and having them check it is my next move, but I wanted to be sure I wasn't missing something.

Chris

[mtnbkr]

You did it, or had it done? Just wondering because on my truck, a total transmission fluid change (not just what's in the pan) is a major PITA.

I did it. The regularly scheduled change for the Honda is a partial fluid change and doesn't involve a filter change. Honda also put in handy drain and fill plugs. It's not hard at all.

The spec is to drain until it stops, then refill with 3.3qts. I bought 4qts and have a bit over a half qt left.

Chris

[Hambo]

I tried that (changing dipstick orientation) thinking that may be the issue. It didn't help.

Going to a shop and having them check it is my next move, but I wanted to be sure I wasn't missing something.

Chris

Honda recommends the change you did, but your transmission holds a lot more than what you drained and filled. If it was low before your service, it's still low now with what you replaced. I check fluids hot, but I am not obsessive about the time window. If I have issues reading the level, which is often the case with my engine oil, I check several times and go with the consensus. That's probably not too helpful.

[mtnbkr]

Honda recommends the change you did, but your transmission holds a lot more than what you drained and filled. If it was low before your service, it's still low now with what you replaced. I check fluids hot, but I am not obsessive about the time window. If I have issues reading the level, which is often the case with my engine oil, I check several times and go with the consensus. That's probably not too helpful.

Yup. I considered that, but would expect it to read even lower when cold since the fluid must be hot for a proper reading and the same fluid expands when warm. If it were low when cold, I'd just add more, but since it's within the normal ranges while cold, I'm concerned about overfilling.

I'm probably over thinking this, but I really don't want to replace this transmission and would like to get another year out of this van. Odyssey transmissions aren't known to be durable (note that I replaced ours at 98k miles!).

Chris

[Doc_Glock]

I'm probably over thinking this, but I really don't want to replace this transmission and would like to get another year out of this van. Odyssey transmissions aren't known to be durable (note that I replaced ours at 98k miles!).


The engines are pretty amazing though. I have a 2006 at 267k miles currently. No tranny issues on this one but had a 99 that had trans replaced at 80k. I don't think you will have trouble getting another year out of it. They are absolutely beautiful vehicles for the daily grind (and mountain biking)

[willie]

On my 2019 Tacoma, there is no dip stick.

[Mitch]

On my 2019 Tacoma, there is no dip stick.

Same with my 2018 Charger. It’s annoying.


Sent from my iPhone using Tapatalk

[mtnbkr]

The engines are pretty amazing though. I have a 2006 at 267k miles currently. No tranny issues on this one but had a 99 that had trans replaced at 80k. I don't think you will have trouble getting another year out of it. They are absolutely beautiful vehicles for the daily grind (and mountain biking)

No issue with the engine itself, but a lot of stuff bolted to it has been crap (AC, steering pump, AT, timing belt tensioner, etc).

Chris

[Doc_Glock]

No issue with the engine itself, but a lot of stuff bolted to it has been crap (AC, steering pump, AT, timing belt tensioner, etc).

Chris


Engine Mounts have been a recurring source of drama.

[LJP]

Hmmm. I don’t consider myself to have any specific mechanical aptitude, but was always taught to check oil with the engine off and transmission fluid with the engine on and warm and the vehicle in park. At least that’s what we do with the ambulances at my service.

[Joe in PNG]

Back in my mechanic days, I'd generally take a peek at the Owner's Manual, and see what it recommends.
Most tend to go with Warm, Running, In Park, and Level.

I'd also do multiple dips not quite all the way in, and wipe of the stick, to remove the stuff in the tube before checking. Then I'd do it again.

[mtnbkr]

Hmmm. I don’t consider myself to have any specific mechanical aptitude, but was always taught to check oil with the engine off and transmission fluid with the engine on and warm and the vehicle in park. At least that’s what we do with the ambulances at my service.


Back in my mechanic days, I'd generally take a peek at the Owner's Manual, and see what it recommends.
Most tend to go with Warm, Running, In Park, and Level.

I'd also do multiple dips not quite all the way in, and wipe of the stick, to remove the stuff in the tube before checking. Then I'd do it again.

Per my owner's manual, you check it warm/hot with the engine off, not less than 60 seconds after you shut off the engine and not more than 90 seconds after shutting off the engine.

Multiple dips while hot gives me multiple readings ranging from super low to spread all up and down the dip stick.

Chris

[RoyGBiv]

Warm as instructed. Shut off car and start timer.
Immediately wipe dipstick and re-insert.
When timer goes ding, check level.

Once you verify that the level is correct per manufacturers instructions, drive the car into your usual parking spot and let it get cold. Wait several hours. Overnight is better.
Note the ambient temp.
Check the level with the vehicle cold.
Now you know what the level should be cold at XX'F ambient, at whatever level your garage floor is, immediately after confirming you have the correct volume.

I do this with motorcycle oil sight glasses routinely. No problems so far.

[txdpd]

Multiple dips while hot gives me multiple readings ranging from super low to spread all up and down the dip stick.

Chris

Get a rubber plug for the tube. That first pull to wipe the stick gets oil on the inside of the tube. Get it warm with no stick, stick it once and check it. replace the stick, store the plug.

I drain the pan on my Corolla every year and that takes about 3.5 quarts. What I do is drain into a pan, pour that into a jug that has been marked at 128oz, and then use the 4th quart of new fluid to bring the fluid in the jug up to the mark. The rest goes in the car and it amounts to an ounce for ounce replacement. The residual fluids more or less balances out. I've always hit the mark on fluid, I'd rather waste half a quart than mess with trying to get it right later. I've also used a dipstick tube pump on vehicles with or without a drain plug and to make small adjustments on overfills.

IMO you're better off a bit low than too high.

[0ddl0t]

Sounds like the correct reading is at the very bottom of the low range. Try adding 1/4 quart.

[fixer]

If you are 100% confident you added the exact same amount of fluid back to the unit, then there is really nothing much to worry about other than a PITA dipstick reading.

However, if its easy to drain out some fluid, try adding small amounts to see if there is a response on the dipstick.