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Since you're only getting about a third of the total capacity, I've made it a habit of doing a drain and fill at 30,000 miles then with the next two oil changes and do it all again 30,000 miles later. This way you've replaced mostly all if the fluid by the third change.
You can but a 1 gallon measured pitcher at a garden center and know to the ounce exactly what you removed. You easily spilled a couple of ounces so I'd say all four quarts could have gone in.

Clint
 
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Discussion Starter · #3 ·
Thanks clint

Thanks Clint,

I just bought the truck and this is the second time I have done this in about 1600 miles, so that makes 2/3rds new fluid. Without knowing the history of the truck, I wanted to try to put fresh fluid in it.

I was concerned about possible clutch wear, so that when I put in the fresh fluid, that didn't have the clutch material suspended in it, it would slip.

I plan on doing a 4 quart drain and fill every 30K miles, since I will be towing with it...

I might have been able to put the 4 quarts in, but I want the level right to the middle of the "ok" mark, so if the while I am towing, there is room for expansion, since I don't know how much room Nissan provides...

As the dipstick was, the level was way past the half way mark, and within say a 16th to an 8th of the top mark... I will drive it for a while, and see how it looks after a week.

Since you sit on the transmission while you are driving, there isn't room for a deep pan and sump like on the oil pan. It is a shame because going up hill, the fluid I guess can slop to the back of the pan and the sump can run partially dry. Since it is so shallow, you can overfill it in a hurry.. The other day, when I went to look at the fluid, I pulled out just under 200 milliliters, and it went from totally at the top of the OK mark, to mid way, which is were I wanted it, not knowing how full is over full..

Thanks so much for your reply, and tip!

I had VDC error issues, where the truck would buck and the Slip light, and once the ABS light would come on. I did a few things, and it stopped. New plugs, etc

Not sure if I fixed it, or the EMU just relearned... I am not sure if I posted it here or NICOclub, but I put up a video telling people how easy it is to change the plugs without removing the intake manifold.

I had read were people said "it couldn't be done", so I wanted to add that..

Have a good night, or what is left of it, at this time!
 

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I plan on doing a 4 quart drain and fill every 30K miles, since I will be towing with it...
...
Since you sit on the transmission while you are driving, there isn't room for a deep pan and sump like on the oil pan. It is a shame because going up hill, the fluid I guess can slop to the back of the pan and the sump can run partially dry. Since it is so shallow, you can overfill it in a hurry.. The other day, when I went to look at the fluid, I pulled out just under 200 milliliters, and it went from totally at the top of the OK mark, to mid way, which is were I wanted it, not knowing how full is over full..
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not sure what you mean by "... there's not enough room for a deep pan...". PML makes a newly revised pan that is a hair over 1 qt larger than stock, THICK cast aluminum, finned and fits under a trans skid plate. I have this config. It works great. Even on the trails going slow temps stay slightly cooler (crawling along ~5mph) and when hauling serious weight (bed full of wood for my father's woodstove -max capacity or over) when I get to the flats or downhill side the trans cools down right quick.
I wouldn't bother with the powdercoating (defeats purpose extra cooling) and I WOULD have them tap it for an external temp sensor, you can always just install a plug till you decide to get a sensor (I made this mistake and kick myself periodically). The bottom set of photos is my install. You can see the clearance between the fins & the skid.

By the way, what yr / mileage is your truck?
 
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Discussion Starter · #5 ·
Meh

To explain what i mean about a deep pan. Think about the oil pan on the engine. Now if you wanted to do one like that on the trans, it would illuminate ground clearance, and might get caught on things.

Now it is not the holding capacity that is the issue. The very wide, shallow pans are why level is so critical.

I am going to demonstrate.

Take a measuring cup and measure 4 ounces of water into a standard, tall relatively thin drinking glass. Take a straw and put it into the cup and sip at it. Now turn the cup 45 degrees to that it is is slightly tipped at the top, and try to sip at it.

Observe what happens with the cup strait like sitting on a counter, and then with it tilted 45 degrees.

Now take a wide, shallow container, and fill it with the same 4 ounces. Stick a straw into the container and sip from it, and take note of what happens.

Now tip it 45 degrees, and try to sip from the SAME spot you just did.

Notice, all the liquid ran to one side, and away from your straw?

It is the same with a transmission pan. The entire bottom is the same depth, and shallow, where as the oil pan has a deep well.

The sump for the oil pump in the engine is always at a depth fall below several quarts of oil. So much so, that you can let your oil run probably 3 quarts low on a 5 quart capacity, and you probably will not have issues, as long as the oil sump remains submerged in the liquid. Sure there are issues with that oil getting more dirty quickly, and sludge and such, but I am illustrating a point.

With the trans pan, Even a quart low will likely cause serious issues.

Do you see what I mean?

so it isn't the capacity that is the problem. It is the shape of the pan. The shape is neccesitated by the location of the trans, which runs under your butt to the back of the car.
 

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I think you forgot one important thing about the deep transmission pan. No matter what going up hill, down hill, flat or side ways, the transmission fluid pick up is always submerged in fluid. The shape of the pan doesn't change anything to do with the transmission except adding better cooling and more fluid.

You can not compare and engine oil pan and transmission pan. They are 2 different systems and different in there own ways. you are over thinking it. You said level is critical, that would mean anytime a person drove their vehicle up or down a hill or mountain they would have transmission problems.
 
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It is hard to tell if that is sarcasm or not.

The problem with your straw theory is that, you did not add more water. Remember the deep transmission pan adds more fluid capacity.

The deep transmission pan is like a inground pool with a swallow end and deep end. If we go by what you are trying to explain then the water would be higher in the deep end. Liquids find its own level.
 
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Discussion Starter · #9 ·
It is hard to tell if that is sarcasm or not.

The problem with your straw theory is that, you did not add more water. Remember the deep transmission pan adds more fluid capacity.

The deep transmission pan is like a inground pool with a swallow end and deep end. If we go by what you are trying to explain then the water would be higher in the deep end. Liquids find its own level.
Hey Brother,

I am not trying to be sarcastic at all.

I could just tell you weren't getting what I was trying to say, and I had no idea how to illustrate what I was saying... I didn't want to come off like I was an "expert", because I am not.

However, I believe your logic is flawed. I am not saying authoritatively that this is what happens in a transmission, all I am saying is my theory is very sound.

If you actually do the experiment you will see what I mean. Try to get two containers that hold the same amount of liquid. Shape matters.

The transmission oil pan is very much wider at the bottom, than an oil pan.

Now I would't expect your transmission to run out of fluid when you go up hills because it is filled at the right level. The design of the transmission pan is such that if the fluid level is full, as the fluid runs to one side of the pan, the slump is still fully submerged. If the trans is not full, the sump, which happens to be very wide, with a lot of surface area can be partially unsubmerged, and suck air.

Now as for the other case, of an overfilled transmission, I understand the ATF fluid gets agitated, and becomes frothy. This lowers the density of the oil significantly, and the sump can not supply enough dense oil to drive the transmission, and on the other end, since the oil is aireated, it will not prevent metal to metal contact between gears.

I have not idea what mechanically happens in the Transmission to cause the oil to froth up when it is over full.

Now my theory is sound. I do not in fact know if that is what happens in a transmission. I just know if it the level is too low, you will have slipping and poor shifting. Primarily from lack of sufficient pressure to drive the fluid circuits with enough pressure.

I believe your idea about fluid dynamics is wrong, but there may be another reason why fluid level is so critical on a transmission. However, I think what I am saying might be likely.

I just don't think it is worth arguing about. Especially because I don't claim to be an expert!

I do however appreciate your advice, and intent to help me out!
 
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Discussion Starter · #10 ·
Important update!

Listen, I wanted to come back and add some information for others that might read this looking for the capacity to do this...

If you watch the video, you will see that I drained it, measured it, and put back in 300ml less of 4 quarts. So, it was something like 3.67 quarts I put back into the transmission.

I said that put the level about 1/16th to 1/8th from the top of the dip stick hash marks.

I said in the video that the transmission shifted okay.

I had decided to drain out another 100ml of fluid. The transmission shifts BETTER. When it shifts the shifting process is quicker, more positive and smoother.

There was never any shifting flair, but the process was kind of rough when it shifted. Some times it was nice and positive although with a bigger "shock" than I would like, and other times the actual shift would take longer than I thought it should. For example, you are driving down the road, it shifts at the appropriate RPM, but the shift takes long enough that you go forward in your seat a little. No flair, the rpms stay where they are until going down after the shift, but the process was kind of like a person that isn't that great at driving a manual.

With that 100ml taken out, the shifts are quicker, and smoother, while still being positive.

I also notice another thing. Before when sitting on a hill waiting to back into my driveway in reverse, when I first shifted the car into reverse, it would hold for about 5 seconds and then start to creep down the hill. I thought it was weird, but since the truck was new to me, and I know I am on a hill and the truck is heavy it might be normal for the truck. Even though I thought it was strange....

Now, the truck will hold there all day!

Now to summarize, I think the 3.67 quarts i put back in on the second drain and fill was too much ATF. I think the 4 total quarts I put back in on the first transmission refill was WAY too much!

So someone else on one of these forums nailed it. He said, he would start with 3.5 quarts back in and top it off as needed. I am going to say put back in 3.5 quarts and probably stay around that area...

Work harder to check that the fluid is level is closer to the middle of the upper hashmarks.. It is very hard to see, but work at it.

Measure what you take out, but don't think that is the end all be all, as the person before you, or even the factory could have overfilled.

I can tell you this. Taking that 100ml out, and making the refill amount closer to 3.5 quarts seemed to make a positive change!

I wanted to be sure and add this info as there really are no answers on how much it takes to fill back up. Stay closer to 3.5 quarts and check and re-check, it seems to make a big difference. EVEN THAT 100ML DIFFERENCE!
 
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