Checking Trans Fluid Level

[The_Nuke]

Transmission is the venerable NAG1 (MB 722.6?) that every Dodge LX has in them up until a few years ago. When checking the fluid level on that transmission, I made sure it was up to operating temp (170F), and I ran it slowly through all the gears immediately prior to checking the fluid, landing on R and checking with it still running and in R.

Is that the proper fluid level check procedure, or am I missing something, getting one of the steps wrong, etc.?

I am unable to get a valid reading, which leads me to believe i'm Doing something wrong in my fluid steps.

NOTE: I've checked it before and got readings, and it's running fine, no operating signs of incorrect fluid level.
And when I say I'm getting an incorrect reading, I mean really incorrect. Like 35mm/50% off, incorrect (too low).

 

[The_Nuke]

The more I think about it, it seems like previously I didn't have in a forward/reverse gear when I checked it. I landed on N and left it there to check.

Possible for that mistake in the procedure to manifest itself as a fluid level almost half of what it's supposed to be?

Hmmm, me thinks definitely maybe...

 

[Chris142]

All older Chrysler stuff was checked in neutral because the pump didn't pump in park. That may have changed though.

 

[The_Nuke]

Originally Posted by Chris142
All older Chrysler stuff was checked in neutral because the pump didn't pump in park. That may have changed though.


My curiosity got the better of me and I went back out to the parking lot and tried again with the shifter in N and still got 35mm (supposed to be 65mm). I even tried it in P, but that didn't change it much either way.

I have been doing 2.5 qt drain and fills the last few mornings to refresh the fluid in it (approx 25K miles on it), but I have been careful to add back only as much as I've drained out...I know I have...I think I have...

Missing 30mm of fluid would equate to about 3 qts according to my paper napkin math, is it possible I did a d&f but forgot the f part? Surely not...right?

I just drove 40 miles in stop and go traffic, would it be slipping or running hot if it was 2.5-3.0 qts low on fluid?

Dang, now I'm all worried about my transmission, I'll never be able to do any work today!

 

[andyd]

Maybe apples and oranges. But every RWD AT I've had will shift funny from Low into 2 on the first shift of the day if the ATF is a pint low. It feels and sounds as if you're giving the engine too much gas with the clutch on partially engaged. Dip stick aside, if you feel a weird shift when stone cold, the level is low. A qt low is noticeable when driving.

 

[The_Nuke]

Originally Posted by andyd
Maybe apples and oranges. But every RWD AT I've had will shift funny from Low into 2 on the first shift of the day if the ATF is a pint low. It feels and sounds as if you're giving the engine too much gas with the clutch on partially engaged. Dip stick aside, if you feel a weird shift when stone cold, the level is low. A qt low is noticeable when driving.


Well, the transmission didn't do much shifting (down or up) on its own this morning due to my propensity for using the Autostick functionality to effect the shifts at my preferred shift points. I didn't notice anything out of the ordinary while doing so though.

I'll leave it I regular D and let the trans do all the shifting when I go to lunch and see if it's exibiting any behavior like what you describe.

 

[StevieC]

Here is the chart for your transmission.

If you want the measuring dipstick it's Dorman Part Number: 917-327 (Available on RockAuto or Amazon)

 

[andyd]

The FIRST shift of the day. All the ATF is drained to the lowest point. If it sits for a few hrs,it still hasn't drained down enough for the weird shift.

 

[The_Nuke]

Originally Posted by StevieC

....


If you want the measuring dipstick it's Dorman Part Number: 917-327 (Available on RockAuto or Amazon)


I am using the Dooreman tool and it's showing me 35mm with trans at 170F. According to the chart, I'm supposed to have 65mm, and that's the number I have used previously, which is why I immediately knew something was NOT stirring the Kook-Aid when I measured it this morning.

 

[The Critic]

This transmission is checked in Park. It looks like you need to add some fluid.

 

[StevieC]

Make sure to run it through the gears for several seconds a few times before checking it in park on level ground.

 

[Astro14]

Originally Posted by The_Nuke
Originally Posted by StevieC

....


If you want the measuring dipstick it's Dorman Part Number: 917-327 (Available on RockAuto or Amazon)


I am using the Dooreman tool and it's showing me 35mm with trans at 170F. According to the chart, I'm supposed to have 65mm, and that's the number I have used previously, which is why I immediately knew something was NOT stirring the Kook-Aid when I measured it this morning.


Then you're low. Please see the posted chart. These often leak from the connector plug, and will often wick fluid up the wiring to the TCU. I would do a pan drop, filter change, and swap out the connector plug, then refill according to the chart. Dead level ground, idling in park/neutral, and use a good scanner, or even an IR gun on the pan, to know where your level should be. It's not simple and it's not easy to get this level correct.

 

[incognito_2u]

I have the same transmission in the Jeep in my sig.
What are you using to determine the Temperature of the fluid.....I use a dongle attached to the OBD port and the "Torque" app.
Beside ensuring the transmissions at the proper temperature, make sure that the vehicle is level.
As crazy as it sounds, I usually check this fluid at a local Gas station by me that I know for a fact has level ground at the Pumps ( I checked it with a long level).

 

[The_Nuke]

Originally Posted by Astro14


Then you're low. Please see the posted chart.


I saw the posted chart, and other than the max high/min low lines, I don't think it's any more useful than the two I already have or the one posted by @StevieC earlier. The chart, and the data it contains, is not an issue for me. It would appear as though extracting more than I put back in is my issue...though if I started out at correct level and replaced what I removed, I still cannot find where I lost the missing fluid...I am thinking it must have been the communists.


Originally Posted by Astro14

These often leak from the connector plug, and will often wick fluid up the wiring to the TCU. I would do a pan drop, filter change, and swap out the connector plug, then refill according to the chart. Dead level ground, idling in park/neutral, and use a good scanner, or even an IR gun on the pan, to know where your level should be.


I dropped the pan, cleaned it & and the magnet, and replaced the filter back in June. I also inspected the infamous connector plug for signs of foul-play but did not see any at the time. Ironically enough, I actually inspected it again 4 nights ago when I was under the car trying to figure out why everyone keeps saying I will have to remove the start to change the Crank Position Sensor. There was still no outward signs of trouble at home with the plug or anywhere else on the outside of the transmission, at that time.

I have used an IR gun on the pan just to see how closely it would get me to the actual temperature, and it was surprisingly inaccurate. When the fluid inside it was at 170F, the IR gun aimed at the pan only read back 145-150F. That is not an issue for me, as my EVIC will tell me the transmission fluid temperature if I navigate through the Vehicle Info menu and down to the bottom of the list...well not the VERY bottom, that is reserved for the engine's run-time hours and idling hours...but just above those it will show me the transmission fluid temp.

But only if I am not in Park. If I am in Park and flip to that screen, the temperature it reads out is just the ECT number. Strange, but not crazy...crazy is that it does not have any indication the number in P is not the true trans fluid temp. That seems a little risky to me, but whatever. They didn't ask me how to build their software, so I won't tell them how to make it better.


Originally Posted by Astro14
It's not simple and it's not easy to get this level correct.


I agree, it is not simple, nor is it easy to get the level correct. However, I do not believe it is as much of a big deal as it's made out to be if the fluid level is not correct when the transmission is put back on the road. I mean, I'm at roughly half of the fluid that I am supposed to be running, and it's been like that for days and days evidently, not to mention I've done some decent stunt driving during that period. Yet, not one hiccup or flared shift or delay in responding to my commands to shift during this time of meager fluid.

Are these transmissions just that tough? Eh, possibly...it's also just as likely IMHO that this notion that an incorrect fluid level will cause irreparable harm to the transmission has been blown out of proportion. I am not saying it's good for them, nor would I recommend anyone do it just for kicks, but surely the transmissions aren't so brittle that they can't absorb the shock of being on the wagon for a few days....

 

[The_Nuke]

Originally Posted by incognito_2u
I have the same transmission in the Jeep in my sig.
What are you using to determine the Temperature of the fluid.....I use a dongle attached to the OBD port and the "Torque" app.
Beside ensuring the transmissions at the proper temperature, make sure that the vehicle is level.
As crazy as it sounds, I usually check this fluid at a local Gas station by me that I know for a fact has level ground at the Pumps ( I checked it with a long level).


I used the aforementioned Dooreman tool, and I have also broken out the 36" zip ties and fashioned my own to use. The Dooreman tool is a little wonky to try to use for these transmission IMO. I can never seem to get a straight reading with mine.

I have always had much better luck with my zip ties, no lie!!

 

[jeep58]

How did you check for the right temp on the transmission fluid, have the same transmission hate that they do not have the dipstick like all other cars !!!

 

[The_Nuke]

Originally Posted by jeep58
How did you check for the right temp on the transmission fluid, have the same transmission hate that they do not have the dipstick like all other cars !!!


My EVIC has oil temp and trans temp available, so I was able to just check it. But in the absence of that, you can just drive around for 30 min or so to make sure the trans fluid is up to operating temperature (170F), and then check it, looking for 65mm as the full mark.

If it is significantly off one way or the other, I will say don't panic, it's not nearly as underfilled/overfilled as the reading might indicate.

Mine was 25mm low recently, so I added a quart and a half, then checked it, only to find it was now almost 20mm over. So I extracted about 3/4 of a quart, and now I'm good.

The moral to that anecdote is that even though you might be showing only half what it should be on the dipstick, it's not half a transmission low. It's likely only a quart or so low, if that.